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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1959-U.S.G.S. Professional Paper

Shorter Contributions
to General Geology

1959

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961

UNITED STATES DEPARTMENT OF THE INTERIOR
STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

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CONTENTS

[The letters In parentheses preceding tho titles designate separately published chapters]

(A) Intrenched meanders of the North Fork of the

Shenandoah River, Virginia, by John T. Hitck
and Robert S. Young

(B) Interpretation of the composition of trioctahedral

micas, by Margaret D. Foster

Miller

(D) Early Cretaceous (Albian) Ammonites from the

Chitina Valiev and Talkoetna Mountains, Alaska.
by Ralph W. Imlay .

(E) Interpretation of the composition of lithium micas.

by Margaret D. Foster.

Page

(F) Zones and zonal variations in welded ash flows, by

Robert L. Smith

1 (G) Deposition of uranium in salt-pan basins, by Kenneth

G. Bell

XI (II) Foraminifera from Onotoa Atoll, Gilbert Islands, by
Ruth Todd

(I) Occurrence and significance of marine animal remains

in American coal balls, by Sergius H. Mamay and
Ellis L. Yochelson

(J) Lituyapeclen (new subgenus of Patinopecien) from

Alaska and California, by K. Stearns MacNeil

(K) Stratigraphic Occurrence of Lituyapeclen in Alaska,

115 by Don J. Miller

U. S. GOVERNMENT PRINTING OPSICE : mi O .55V101

Page

149

101

171

193

225

241

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Intrenched Meanders of the
North Fork of the Shenandoah
River, Virginia

By JOHN T. HACK and ROBERT S. YOUNG

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 3 5 4- A

A study of the channel of a river
intrenched in hard rocks
and an analysis of factors
that cause it to meander

UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington 25, D.C. - Price 20 cents (paper cover)

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CONTENTS

i’nre

Abstract 1

Introduction 1

Geology of the river basin 2

River channel -I

Longitudinal profile 4

Channel cross section 4

Bed material 4

Discharge 0

rase

River channel — Continued

Summary of channel characteristics 0

Controls of meander formation 6

Intrcnchment hypothesis 7

Meandering streams in rocks other than the Murtinsburg

shale 9

Conclusion !•

References 10

ILLUSTRATIONS

Plate I. Outcrops of Martinsburg shale. .1, Outcrop near Woodstock showing typical l>cds of fine sandstone and siltstono

alternating with shale; /?, Outcrop near Udinhnrg showing typical prismatic cleavage cutting a spheroid Facing 6

FIGURE l. Map of the meandering reach of tile North Fork of the Shenandoah River 2

2. Simplified geologic map of the drainage basin of the North Fork, Shenandoah River 2

3. Longitudinal profile of the -North Pork of the Shenandoah River 1

4. Graph on logarithmic scales comparing the dimensions of the channel of the North Fork at different places along

the stream. , .

5. Profiles of valley floor

Table 1. Summary of data on size of fragments on the streambed. North Fork, Shenandoah River, A

2. Mean annual discharge at gaging stations on the North Fork of the Shenandoah River 6

111

.wawu

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loc bi

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

INTRENCHED MEANDERS OF THE NORTH FORK OF THE SHENANDOAH RIVER, VIRGINIA

By John T. Hack and Roiiert S. Yoi.no 1

ABSTRACT

Tin- North Fork of the Nhemuiilonh River traverses rocks of
different, lithology iti ureas of greatly different to|s>Rraphy.
The S|K*ctneutar uieamlers In which the river travels 3.2 times
ns far as the direct down valley distance coincide with the out-
crop area of a belt of Martinstnirg shale. Along the entire
river the channel is adjusted to carry bed material of approxi-
mately uniform slate, and passes through the meandering reach
without significant change in chuunel cross section. The pro-
file of the stream follows a simple logarithmic curve from
source to mouth. The upland on either side of the stream,
however, slopes downstream at a grade much steelier in the
area of the meanders than in the non meandering area u|istream.
It is concluded that the meanders are caused by strong planar
and prismatic structures in the Martinsburg shale that favor
uort Invest -southeast differential erosion. The topography of
the adjacent uplatid is graded to the present river. There is no
reason to believe that the river has been intrenched from nil
erosion surface on which the relief was less than that of the
present upland or that changes In base level have inllueuced the
meander development.

INTRODUCTION

The North Fork of the Shenandoah River, Va., is
a classic example of a meandering stream intrenched
in hard rocks. Photographs of these meanders have
appeared in several te.xl hooks of geology and geoinor-
phology (Thompson, 1047, p. I7f>; Monnett and Brown,
1950, p. 110; Thornbury, 1954, p. 146). The meanders
are prominently displayed in an illustration in a paper
hj' Rich ( 1939) describing a section across the Appa-
lachians. Butts (1940, p. 508) oilers an interpretation
of the origin of the meander Ixdt, and Fisher (1955)
describes the physical character of the meanders.

A similar meander belt on Conodoguinot Creek, near
Harrisburg, Pa., has received at least an equal amount
of attention as an example of an intrenched stream and
has been studied by Strahler ( 1946).

Most authors who mention either of these meander-
ing streams imply that they are inherited from a sur-
face of low relief and were intrenched into the valley
floor during rejuvenation, as a consequence of uplift
or change in base level. As pointed out hv Thornbury,
however (1954, p. 145), geomorphologists are not

* University of Virginia, formerly of the Virginia Division of Geology
(now the Virginia Division of Mineral Resource*).

agreed that all intrenched meanders have been formed
in this way. For example. Cole (I960) has shown that
meanders may form in hard rocks by erosion along
joint, planes. Gregory and Moore (1931, p. 136) l>e-
lieve that many of the meanders that, are sjiectacular
features of the Colorado Plateau region were formed
by lateral corrusion of the hard rock strata.

The writers believe that the meandering reach of t he
North Fork of the Shenandoah River is simply a river
segment with a smooth and regular profile, adjusted for
the transportation of a certain load. The enclosing
rocks have special characteristics favoring erosion in
a preferred direction, and the adjusted channel slope
is maintained in spite of the increase in sinuosity. No
change in base level is necessarily involved in the for-
mat ion of the meanders.

The meandering reach of the North Fork is shown
in figure 1, a map prepared from the Strasburg and
Edinburg quadrangles of the Ll.S. Geological Survey.
The reach begins at Edinburg and ends at Strasburg,
14 miles downvallev. The sinuosity (the distance
measured along the stream, divided by the distance
measured along the valley) attains the remarkably high
value of 3.2. The narrow valley bottom is 100 to 150
feet below the general level of the adjacent shale hills.
Measured along the channel, the river lias an average
gradient of 5.5 feet per mile, whereas the valley floor,
measured across the hilltops lietween the bends, has a
gradient of 17 feet per mile. As shown on the geologic
map, figure 2, the meander belt is localized within (lie
outcrop area of the Martinsburg shale (Ordovician).
This formation, as described on page 6, is lithologic-
ally unique in the region and its close relation to the
meanders led the writers to undertake this study. The
relation is not. confined to the North Fork; similar
meanders occur in other areas of Martinsburg shale, as
on the Middle River, Augusta County, Ya., and on
Conorochengue Greek, Washington County, Md. In
these areas the meandering reaches correspond closely
to the limits of the same format ion.

The writers' work on the Shenandoah River grew out
of bedrock geologic mapping by It. S. Young in the

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

B<**-t* horn u $ Geological Survey topographic

map :i» Ihr Slr^buig quadrangle

Figure 1. — Map of tlie meandering reach of the North Fork of the Shenandoah River. Redrawn from the Strasburg. Va.. quudrnnglt* of the

U.S. Geological Survey (1047).

Edinburg- Woodstock nrai in 1051-52, and studies of
streams by J. T. Hack in the Shenandoah Valley in
1952-57. Measurements of the stream channel were
made in 1957. The writers are grateful to colleagues
in the Virginia Division of Geology and the. U.S. Geo-
logical Survey for their suggestions and critical review.

GEOLOGY OF THE RIVER BASIN

The valley of the North Fork may be, divided into
three parts, each having distinctive geology, as shown

on the map of the river basin, figure 2. The head-
water area above Cootes Store is in folded sandstone
and shale of Silurian and Devonian age. The inter-
stream divides are steep sandstone ridges rising 1,500
to 2,000 feet above the shale valleys. Along the main
streams the valleys are broad and flat floored. The
channels are flanked by broad flood plains and gravel
terraces. Rock is not exposed in the channels, and the
beds and banks are composed of rounded cobbles in
imbricate arrangement, derived from the thinking

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INTRENCHED MEANDERS OF THE NORTH FORK OF THE SHENANDOAH RIVER, VIRGINIA

?e e 30

78® lb'

79® 00'

5 I

5 9z

)3<§
J ^ Q

)ii

J IA(£

)gl

Mnninsburn: nhwl** ' a U

CdfotrWta* tkalt aw rj _j O >

38® W

I I

j Eoy

CD Z >
s < O
< °
u ?

Thrust fault

T. «),/#*<• p/ol*

j-- i

15 Miles

FioOM 2. — SlmpUllnl geologic map (if 111# ilraloagc bnxln of tlie North Fork, Shenandoah River, shooing relation of the meanders to the

Martlnaburg shale, and location of proQlea (Og. 51.

sandstone ridges. In tin* segment of the river
from Cootes Store, to Edinburg the river crosses the
main Shenandoah Valley, a rolling country with an
average relief of about 2(H) feet, that is underlain by
Cambrian and Ordovician carbonate rocks. The river
is bordered by terraces, narrower than those upstream
but nevertheless considerably wider than the channel.
In a few places terraces are a mile wide. The width of
t.he flood plain and terraces diminishes, however, in a
downstream direction. Hanks and IhhI are composed
primarily of cobbles of sandstone transported from

upstream. Above Broadway the river crosses the st rike
of the rocks at right angles. Below Broadway it
parallels the strike following closely a belt of limestone
at the top of the Cambrian. As far as Mount Jackson
it remains on the northwest, side of prominent and
resistant cherty l>eds in the Beokmantown dolomite
(Ordovician). Just above Edinburg the river crosses
the cherty beds and enters a belt of Mart inshurg shale.

Below Broadway, outcrops of limestone occur in the
l»ed in many places. From Mount. Jackson to Edin-
burg limestone outcrops are more numerous, and the

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

strenmbed coni u ins angular cobbles and boulders of
limestone of local origin equal in number to the sand-
stone cobbles transported from upstream.

The. third distinctive segment of the river is the
meandering reach extending from Edinburg to beyond
Strasburg. In this segment the river Hows on the
Martinsburg shale, a tightly folded belt of weak silt-
stone, fine sandstone, shale, and subordinate calcareous
shale, that has a prominent fracture cleavage and joint
system oriented northwestward. The river is Hanked
on the southeast by the steep shale slopes of Massanut-
ten Mounrain, a complex syncline. The side of this
mountain that borders the North Fork has a core of
hard quartzite, of Silurian age, exposed at the crest.
The quartzite breaks up in boulders forming talus
slides and block Helds that extend down the hollows in
the mountainside to the meander bends of the river.
In contrast to the upstream reaches, the riverbed in the
meandering segment is mostly exposed ljcdrook.
(travel and cobbles occuply less than one third the area
of the bed. The channel is bordered by a narrow Howl
plain and in some places by gravel terraces. In three
places the terraces occupy abandoned meander loops *20
to 40 feet above river level.

RIVER CHANNEL
LONGITUDINAL PROFILE

It is of first importance to consider whether the
profile is smoothly graded or whether there is a break
in grade, an irregularity, or other change that marks

DISI»NCl IHOVSCOHa IN WILIS

Florae 3. — Longitudinal profile of the North fork of the Shenandoah
Ittver, The distance from the source Is measured alone the longest
or principal stream of the drainage basin which bends on the Vir-
ginia-West Virginia boundary nt lnt 38*40’ N. The horizontal scale
Is logarithmic.

the beginning of the meandering segment. Examina-
tion of the profile, measured along its channel, shows
that it is uniform. The profile follows fairly closely
a simple logarithmic curve, as shown in liguro 3,
though there are departures from it. It is a property
of such a profile t hat, the channel slope (N) at any point
on the stream is inversely proportional to the stream
length ( L ) (the distance from the source to the same
point.) The ratio of the slopes at any two points (-S,
and S 2 ) is equal to the reciprocal of the ratio of the
lengths of these points (/d and L s ) •

5 _ b_

~ u

CHANNEL CROSS SECTION

Channel cross section is a significant factor affecting
the adjustment of the stream to its load. If there were
changes in the nature of the equilibrium conditions in
the channel the cross section might be expected to
change. The results of measurements made by traverses
with tape and hand level across the channel from flood
plain to flood plain are shown in figure 4. The varia-
tions within a reach are much greater than the varia-
tions between the meandering and nomneandering
reaches. Therefore no significant difference can lie
shown.

BED MATERIAL

Hock fragments resting on the bed of the North
Fork are course throughout and consist of pebbles,
cobbles, and boulders. The bed material was sampled
nt several loealit ies, including two in the lower or
meandering segment, two in the middle or limestone
segment, and three in the upper segment above Cootes
Store. Size was estimated by measuring the inter-
mediate diameters of more than 50 fragments on the
stivanibed selected at regular intervals along a tnj>e
stretched across the streambed. The size statistics at
these localities are given in table 1.

Taiii-E 1 . — Summary of data on xise of frnpinrnl * on the xlrcam-
hrd, North fork, Shenandoah Hirer

fKl'ttill* |>( iuml>w.< made In I lie fu'bl by rite Wolman mil hod (Woltnan. 1#M;

Hack, l»7)|

Locality

Number

dtscmtnl

Miles
fro: it
source
of river

ul f'av-
nuins In
simple

rhi

mean

J*iW

rhi

deviation

< Jeornct-
rlc mean
(mm)

tjtml*
stone in
sample

Cp|KT scRmenl

7 x

.'41

-«.*!

1. 15

7ft

ion

I.V 1

i :v.

IIN>

KMI

|H. S

-ti.ir.*

«4

KKI

— -------- ■

■ — - -

• w >u <

. . . .

— — _ . — .

M i* If Ur* M»:mcnt

(limestone!

WL 2

7i*

-.von

1 to

IX J

lift

-IV IN!

1 4fi

Lower segment

■

(Mnrtliubun;

shale t.

TV .i

4.'.

1.74

V2 7

Mil

—Ik Ml

1.37

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INTRENCHED MEANDERS OF THE NORTH FORK OF THE SHENANDOAH RIVER, VIRGINIA

Cootes Store Edinburg

10 SO 100 200

MILES FROM HEAD OF north FORK SHENANDOAH RIVER

Fiouiik 4. — Grii|'li on lugarltlunlc ucales comparing the dimensions of
the channel of the North Fork nt different places along the stream.

These statistics do not apply strictly to the traction
load that is moved day by day or month by month.
They describe material that is now on the bed, some
of which has la*en moved from upstream, and some of
which is residual and represents a lag concentrate of
fragments torn otf the bedrock locally but- that is not
yet broken into sizes small enough to have been moved
in the last flood. It was shown by studies in other
streams in the Shenandoah Valley (Hack, 1057, p. 70-
87), however, that siliceous rocks like sandstone and
chert are moved great distances downstream from their
source, whereas rocks like limestone and shale arc soft
and are not carried far downstream before they are
broken into sizes too small to remain as a lag concen-

trate on the bed. Inasmuch as the lied samples of the
North Fork all contain sandstone from upstream, in
addition to locally derived rocks, and the sandstone is
on the average coarser than the local rocks, it is in-
ferred that the river is competent to move material
of the size that is on the bed.

The sampling indicated no significant change in size
of lied material along the stream, as shown by an analy-
sis of variance of the phi mean sizes. The bed mate-
rial is equally as course or coarser near the mouth, in
the meandering reach at mile 92.7, as it is near the
source, at mile 7.8. The lack of change of particle size
along the stream is related to the regular form of the
longitudinal profile. Studies in a wide selection of
streams in the Shenandoah Valley and in nearby Mary-
land and Virginia (Hack, 1957) show that the range in
the size of fragments on the streumljeds is from mean
sizes more than (500 millimeters to mean sizes less than
10 millimeters. These size variations are related to
differences in discharge, channel slope, and to other
hydrologic variables as well as to the material itself,
and it was shown that streams with the comj>etonce to
move the material of the same size along their entire
course, have longitudinal profiles like that shown in
figure -'1, of the North Fork. In such profiles the fall
is proportional to the logarithm of the length, and the
channel slo|>e is inversely proportional to the length.

The problem is illuminated by consideration of the
relative proportions of the materials on the bed. It is
noteworthy that in the upper segment the bed material
is all sandstone. This is an area of high relief in which
many tributaries enter (he stream from ridges composed
predominantly of sandstone of Silurian and Devonian
age. Although the river itself is flowing in a shale
valley, the bedrock is so soft, relative to the sandstone
introduced by the t ributaries, that the bedrock is broken
up and carried away in small fragments, and the pro-
port ion that remains on the l>od is too small relative
to the sandstone to appear in the sample. In the middle
segment (Cootes Store to Edinburg), where limestone
is the dominant bedrock, sandstone on the bed dimin-
ishes in relation to limestone. This is because the part
of the drainage basin underlain by sandstone diminishes
ns the basin enlarges in the limestone region. In the
lower segment, underlain by Martinsburg shale, the
proportion of sandstone diminishes still further, and
fragments of Martinsburg shale, although much softer,
make up three- four! Its of the total material in transit
on the bed.

Although not shown in table 1, wherever sandstone
bed material is mixed with shale and limestone frag-
ments, the sandstone component is the coarsest. The
mean size, of all the bed material sampled averages (58

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

millimeters. The mean of all .sandstone fragments is
78 millimeters, and the mean of all limestone and shale
fragments is 50 millimeters. Sine© sandstone is the
most resistant material it determines the size of the
other components of the lied material. Fragments of
locally derived rock that are much smaller are quickly
transported downstream, whereas larger fragments
accumulate at their source until they are broken into
sizes small enough to be moved by traction. The size
of the sandstone fragments must be a function of sev-
eral factors including inherent properties of the rock,
such as its toughness, and the spacing of joints, and of
external factors such as the distance from the source
and rate of transport. If the sandstone were all de-
rived from the headwater area above Cootes Store the
size of fragments on the IkkI probably would diminish
downstream as it does in the Middle River (Hack, 1057,
fig. 38). In the North Fork, however, the load of large
sandstone fragments transported only short distances is
renewed downstream by tributaries like Smith ('reek
and by rock discharged into the stream from the slopes
of Massanutten Mountain.

DISCHARGE

The North Fork shows a regular increase in dis-
charge as the drainage area becomes larger. Data on
the average discharge are available at three gaging
stat ions along the river as shown in t able 2.

Table 2. — i lean annual discharge at gaging station s on thr Worth
Fork of thr Shenandoah Hirer
[Commonwealth ol Virginia. Division ol Water Hwourow. 1»S2|

Intention of Karo

Drainage

arm

tttiuurc

mifoO

length of
rewml
(years)

Average

annual

iliM'llUVgl*

(cfs)

Cootes Store - - . . . - . - .

215

181

Mount Jackson

500

351

Strasburn

772

508

SUMMARY OF CHANNEL CHARACTERISTICS

The North Fork of the Shenandoah River has a
smooth longitudinal profile so regular that it follows
closely a simple logarithmic curve throughout its
length. Measurement of the bed material indicates
that the channel slope and cross section are adjusted
with the available discharge so as to transport bed
material of the same size. This size is determined in
part by t he physical properties of sandstone Inals of
Silurian and Devonian age, the most resistant rocks
of the drainage basin. The adjustment of various fac-
tors seems to be precise with regard to the ln*d mate-
rial and longitudinal profile. This adjustment is
maintained throughout the entire river course in spite

of great changes in bedrock conditions and in the
sinuosity of the river.

CONTROLS OF MEANDER FORMATION

The close correlation of the meanders with the out-
crop area of the Martinsburg shale (fig. 2) shows that
the meanders are related in origin to this formation.
Furthermore, other rivers in the Shenandoah \ alley
have elongate meanders in the same rock formation.
The straight, reaches of the North Fork within the
meander belt, all trend uniformly northwestward, al-
though as reported by Fisher (11155) the river has some
short, rectilinear reaches less than 1,000 feet long at the
bends that trend N. 40° E.

The Martinsburg shale consists of thin laminae al-
ternately of fine-grained sandstone, siltstone, and shale.
Calcareous beds occur at some horizons, particularly
near the base of the formation. A typical lithologic
unit is exposed in a roadcut shown in plate 1. A sec-
tion 25 feet thick at this locality contains 8 fine-grained
sandstone beds averaging 2.3 feet in thickness and 7
siltstone and shale beds averaging 1.0 feet in thickness.
The sandstone beds are notably more resistant to ero-
sion than the slmle. In the river channel the fine
sandstone beds stand up as slablike corrugations, sepa-
rated by grooves of shale, in places 2 feet deep. The
corrugations are prominent and striking features of
the riverbed for long distances, and at low-water
|M*riods form straight lines crossing the water surface
northeastward at right, angles to the channel hanks.

The prominent slalts or laminations are cut. hv a
strong joint system in which the most sharply defined
planes are alined northwest-southeast. There is also
a prominent fracture cleavage. The siltstone lieds, in
particular, are broken into crude match-shaped
prisms whose long axes are oriented northwestward
parallel to the principal joint planes. The prismatic
cleavage is independent of the bedding. This structure
is illustrated in plate 1. Spheroids are common in the
Martinsburg, especially in the more massive siltstone
beds. These hear no apparent relation to the fracture
cleavage, which cuts through them.

Another characteristic of the Martinsburg shale that
may favor meander development is its relatively low
resistance to erosion. The shale is commonly found
in the lowest parts of the valleys and is nowhere a
ridge maker.

Examination of the meanders (fig. 1) shows that, un-
like alluvial meanders, they consist of long straight
reaches connected by 180° bends. The amplitude of
the meanders is irregular and in places is more than
twice the value of the wavelength. Alluvial meanders,
on the other hand, are more symmetrical. The curves,
or arcs, that form the bends generally exceed 180° of

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UKOIAXilCAI. SURVEY

PROPER S ION A I# PAPER 354

PLATE 1

A. OUTCROP NEAR WOODSTOCK

Showing typical b«<i« of hoc *in<l«tor.c and ultatour alternating with ihalc

tt. OUTCHOP NEAR EDINBURG

Showing typical pritmtlir cleavage cutting a aphrroid. The tmill talua apron
at r lit ht i» composed of ailutonr pri«m*

OUTCROPS OK MARTI NSBURG SHALE

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INTRENCHED MEANDERS OF THE NORTH FORK OF THE SHENANDOAH RIVER, VIRGINIA

arc, and the amplitude is regular and may be nearly
equal to but rarely larger than the wavelength. In
alluvial meanders, crossovers (where the current
crosses from one side of the stream to the other) gen-
erally occur at the same {mint on the l»en<ls. In the
North Fork, crossovers occur not only on the IhmkIs
but also in the straight reaches. This phenomenon is
a consequence of the extraordinary amplitude of the
meanders.

The North Fork meanders bear at least one similar-
ity to alluvial meanders, however. Their wavelength
is regular and is a function of the discharge or width
of the stream. Opequon Creek, for example, and the
Middle River, which are smaller streams in the Shenan-
doah Vailey, have meanders of the same, type but the
wavelengths are smaller. Leopold and Wolmnii (1957,
p. 58) have shown that there is a regular relat ion be-
tween the wavelength of the bends in a stream and the
channel width and discharge. Streams with a chan-
nel width of 250 feet, like the North Fork, have an
average meander wavelength of about 8,000 feet. The
wavelength of the North Fork meanders is 1,000 feet
which is in agreement with Leo]X>1d and Wolmnn’s
data, considering the range in variation.

In summary it has been shown that the North Fork
has throughout, its length just the sIojh* and cross sec-
tion required with the gradually increasing discharge
to transport the more resistant rock fragments eroded
in the drainage basin. The extraordinary elongate
meanders are formed in the least resistant ris k of the
drainage basin and follow closely planes of structural
weakness in that- rock. In the upstream reaches the
riverbed is mostly covered by cobbles and boulders,
whereas in the meandering reaches the bed is mostly on
exjjosed bedrock. The river travels a much greater
distance within the meandering reaches for a given
down valley distance than it does in the non meandering
reaches, and a larger pro|Hirtion of the valley floor is
occupied by stream channel.

The explanation for the meanders, then, is that in
the Martinsburg shale the river channel was cut along
lines of structural weakness in the rock while the sIo|»e
and cress section necessary to transport cobbles and
boulders derived from upstream or from tributaries was
maintained. The lesser amount of sandstone and other
t ransported cobbles on the lied suggests that in the
meandering reaches, greater energy has been expended
in the excavation of rock by elongation of the channel
and less by the transportation of rock fragments. In-
stead of a lied composed largely of cobbles the river
has a lied mostly of shale arranged in projecting
laminae that resemble a washboard. These projec-
tions may supply a frictional resistance to streamflow
similar to the resistance supplied upstream by gravel

and cobbles and thus maintain the equilibrium of grade
and cross section. Spacing of the meanders, as shown
by a comparison with typical alluvial meanders, is a
function of hydrologic factors rather than factors re-
lated to the lied rock.

INTRENCHMENT HYPOTHESIS

The argument in the preceding pages disposes of the
hypothesis of meander origin suggested by Charles
Butts (1940, p. 508), which supposes that the meanders
are inherited from alluvial meanders formed on a
(Mmeplain and that they have been preserved but modi-
fied in shape as the river was rejuvenated during a
postulated Pleistocene regional uplift. The meanders
are coincident with the outcrop area of the Mart insburg
shale, and are related in origin to structural properties
of that formation rather than to an alluvial deposit
that has been removed.

It has bean noted by many geologists, however, that
the North Fork is bordered by steep valley walls, and
the stream has often been referred to as intrenched, or
entrenched (for example Thornbury, 1954, p. 146, fig.
6.2). The word "‘intrenched" itself implies that the
river has cut down through bedrock in a narrow valley
but that at one time it flowed across a more open plain
such as a peneplain or at least an open valley less nar-
row than the present one. If this were the case pre-
sumably the meanders developed during intrenchment.

The topography adjacent to the river is now con-
sidered to determine whether the intrenehment hypoth-
esis is necessary in explaining the valley. Figure 5
shows a series of transverse profiles across the Shenan-
doah Valley from Massanutten Mountain to the sand-
stone ridges on the northwest. Profiles A-A’ to
!>-!>’ cross the valley in the limestone area above the
meandering reaches of the river, whereas profiles
K to //-//' cross the meanders. The topography
ns illustrated by these profiles is hilly and irregular.
It is not feasible on the basis of this topography to
reconstruct a hypothetical peneplain or erosion surface
of low relief. The hilltops are too irregular in altitude
and in relative height above the streams. Further-
more, study of the. geology of the. area shows that the
height of the hills is closely related to their lithologic
composition. The high hills in the western part, of
profile .4-.!'. for example, are underlain by limestone
containing thick lieds of chert. If the area ever were
a peneplain its surface must have been above the present
topography.

The narrow, liedrock valley of the North Fork typi-
fied by the cross section 77-//' (fig. 5) is adequately
explained without recourse to the idea of peneplanation
or a surface of low relief. The topography along the
North Fork is an equilibrium or graded topography

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

LINE CONNECTING POINTS IN CHANNEL OF RIVER AT
SECTIONS A-A' TO H-H'

LONG PROFILE OF CHANNEL (INCLUDES BENDSi

fioiiiE 5.- Profile* with greatly exaggerated vertical scale showing the relief of the floor of the Shenandoah Valley In the outcrop area of
Cambrian and Ordovician limestone mid shale. The location of the profiles is shown on figure 2.

like that described by Hack and Goodlctt (in press,
19(50) in an area nearby, or by St raider (1950) in l lie
Verdugo Hills, California. As shown by many recent
geomorphological works, principally that of Horton
(1945), drainage networks are characteristically regu-
lar in pattern and the density of drainage of streams
of the same order tends to be nearly constant in areas
of the same climate and geology. As a consequence the
interstream divides form a system of ridges rising almve
the streams about the same height. A large trunk
stream in such a network of valleys ami ridges appears
to be intrenched because it is bordered mostly by the

steep slopes of interstream areas. These slopes are
graded for the transportation of soil and rock frag-
ments by the process of creep, ami hence arc convex
upward. The streams that intersect the trunk streams
are mostly first-order streams and they intersect,
at a high angle. The ap|>earanc8 of intrenclunent is
enhanced if the topography is underlain by a non-
resistant rock on which the profiles of the interstream
areas are convex upward and therefore appear rounded
or flattish.

Such a topography may be said to lie composed of
slopes that are everywhere in a state of continuous

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INTRENCHED MEANDERS OK THE NORTH FORK OF THE SHENANDOAH RIVER, VIRGINIA

adjustment so ( hut the materials weathered and eroded
from (lie. surface are transported through a network
of channels into larger and larger trunk streams. De-
pending on the rate of erosion and the total relief, the
average slopes of such a topography may lie very steep
or very gentle.

The longitudinal profile of the North Fork shown
at. the bottom of figure 5 by the. line J'-l", is drawn
along the channel and includes the bends of the
meanders. It is a smoot h curve, gently concave upward
and is of simple form because adjusted to transport
material of the same size with a gradually increasing
discharge. The profile above it (that has a larger
horizontal scale) connects points in the river channel
along a nearly straight line. It does not include the
meander trends and therefore represents the profile, as
the crow Hies, drawn along the lowest points of the val-
ley bottom. This curve is steeper in the meandering
reaches than in the reaches upstream. The adjacent
network <>f tributary channels and intervening hills are
graded to the main trunk channel, and therefore the
entire topographic surface adjacent to the North Fork
has a downvalley or northeast ward component of sIojk*.
that is stee[>er in the meandering region than in the
part upstream.

If the topography adjacent to the North Fork can be
satisfactorily explained as a graded topography or a
topography in which the erosions] slo|>es are in equi-
librium. then the meanders exist simply because they
are in the Martinsburg shale, and we can expect, that
any river of comparable size with the gradient necessary
to transport cobbles and boulders will also meander in
the Martinsburg. An exception to this generalization
would 1 h> a stream so heavily loaded with waste of
material derived from upstream that, the IhhI and banks
would be blanketed by this material thereby insulat-
ing the river from the shale.

It becomes pointless to speculate on the geologic
history of the North Fork and the manner in which
it has cut down into the Martinsburg. The. river may
have eroded its way downward in the northwest limb
of the Massanutten syncline thousands of feet, and may
have developed and maintained a meandering course
in the Martinsburg shale in the distant geologic past.

MEANDERING STREAMS IN ROCKS OTHER THAN THE
MARTINSBURG SHALE

Meandering streams of the Shenandoah type are
common in the central Appalachians, and they are not
all confined to the Martinsburg shale. Meandering
reaches are spectacular in the Middle River, Augusta
County. Yn., in Cambrian limestone. The l’otomac

River has well-developed meanders that, are apparently
structurally controlled in rocks of Devonian age.
Meanders almost as striking as those in the Martins-
burg shale occur in southwestern Virginia in metamor-
phic rocks on both sides of the Hlue Ridge escarpment.
The New River, Reed Island Creek, Dan River, and
Blackwater River, for example, display meanders with
extreme amplitudes. The meanders of the Dan, like
the meanders of the North Fork, are confined in
strongly laminated rocks, although the rocks are meta-
morphie with alternating thin layers of quartz mica
schist and amphibolite schist.

CONCLUSION

The meanders of the North Fork have been explained
within a framework of ideas in which rejuvenation and
a former surface of low relief are not factors. In the
writers’ hypothesis the meanders arc an essential part
of a graded, erosional topographic system. The ar-
rangement of the rocks in spare and the action of
hydrologic factors on them is the lmsis for our explana-
tion of the topography and pattern of drainage, rather
than a change in regimen or slope resulting from an
uplift.

The elevation of the mouth of the North Fork is
determined largely independently of conditions in its
own drainage basin, for it. empties into a much larger
stream, the South Fork, which determines the local
base level. The elevations of the headwaters of the
North Fork are also to some extent determined inde-
pendently for they are related to the physical and
chemical resistance of the rocks under the drainage
divides. Between these two independently fixed points
the profile of the stream is determined by a combina-
tion of factors, some local — related to the recks along
the channel — others related to duties imposed from up-
stream such as quantity of water and size and amount
of la*d material. The meanders result from the inter-
action of these factors with those of local origin re-
lated to peculiar structural properties of the enclosing
rock.

I Leopold and AVolman (1057), dealing primarily with
streams flowing in alluvial channels, have demonstrated
ft close relation between hydrologic factors, including
channel sIojh*, discharge, and load, that apparently de-
termine whether or not a stream will meander. It seems
from our data and analysis that the meanders of the
North Fork, even though in bedrock, exist in harmony
with the same kinds of factors. Probably st reams that
meander in bedrock ore actively eroding streams that
have a relatively small load for the slope and discharge
and t hat erode weak rocks with strong linear and planar
structures.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

REFERENCES

Hulls, diaries. 1940, Geology of tlie Appalachian Valley In
Virginia : Virginia Geol. Survey Hull., v. 52, 3(18 i>.

Cole. W. S.. 1030, The interpretation of Intrenched meanders:
Jour. Geology, v. 38, p. -123 -430.

Commonwealth of Virginia, Division of Water Resources, 15152,
Surfaee water supply of Virginia, 1’otoiuae, Rapimhannoek.
and York River ltnsins. 1942-50: Commonwealth of Vir-
ginia, Dept, of Couserv. and Devel. Hull. 12. 372 p.

Fisher, C. (5.. 1955, Elongate meanders of the North Fork of
the Shenandoah River [nbs.] : Geol. Sne. American Bull.,
v. 60, p. 1087.

Gregory, II. E.. and .Moore, R. C., 1931. The Kalparowlts region:
a geographic ami geologic rei-onnalssaui-e of |uirts of Utah,
and Arizona : U.S. Geol. Survey I’rof. I’aper 104, 157 p.

Hack. .1. T., 1957, Studies of longtltudinal stream profiles in Vir-
ginia and Maryland: U.S. Geol. Survey I’rof. l’nper 294-B,
p. 45-97.

Hack. J. T., and Goodlett. J. C., (15X10). Geoinorpliology and
forest ecology of a mountain region in the <-«>utral Appa-
lachians: U.S. Geol. Survey I’rof. I’aper 347, in press.

Horton, It. K., 15M5. Erosional development of streams and their
drainage Imsins: hydrophysicul approach to <)uantitatlve
morphology : Geol. Soo. American Bull., v. 50, p. 275-370.

Leopold, I„ It., ami Wolman, M. G., 1957, River channel pat-
ients : braided meandering and straight : U.S. Geol. Survey
I’rof. l’njier 282-B, p. 39-84.

Mon licit, V. E., and Brown. 11. E., 1950, The principles of physi-
cal geology : Boston, Ginn & Co., 450 p.

Rich, John L., 1939, A bird's eye cross section of the Central
Appalachian Mountains and I’latean, Washington to Cin-
cinnati ; Geog. Rev., v, 29, p. 501-586.

Strahler, A. X.. 1910. Elongate Intrenched meanders of Conodo-
guluet Creek, l’n. : Am. Jour. Sel., v. 244, p. 31-10.

— 1950. Equilibrium theory of erosional sloites approached

by frequency distribution analysis: Am. Jour. Sci., v. 248,
p. 673-696 and 800-814.

Thompson, H. D., 15*47, Fundamentals of earth science: New
York. John Wiley & Sons, 618 p.

Thornbnry. W. I)„ 1951, I’rinclples of gcomorphology : New
York. John Wiley A Sons. 618 p.

U.S. Geological Survey, 1947, Strasbnrg quadrangle, Virginia,
scale 1 :62.500, shaded relief.

Wolman. M. G.. 1954, A method of sampliug coarse riverbed
material : Am. Geophys. Union Trans., v. 35. p. 951-956.

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Interpretation of
the Composition of
Trioctahedral Micas

By MARGARET D. FOSTER

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-B

A study of the compositional and
layer charge relations of
phlogopites , biotites , siderophy llites
and lepidomelanes

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documcnst, U.S. Government Printing Office
Washington 25, D.C. - Price 35 cents (paper cover)

CONTENTS

Alkstruct ... . .

Pus

Magnesium replacement system

Introduction

Fhlogopites

Laver charge relations of the trioctahedral micas, then-

Knstonitc* . _ _ _ _

ret.iral

Biotites . . . _ _ _

liMlrnl mien*

Siderophvllites and lepidomelanes.

Calculation of formulas

Chemical composition and geologic occurrence

Excluded analyses and formulas

Discussion of relation between mica composition and oc-

Accommodation of extra positive octahedral charges

currence

in micas studied

Summary and conclusions

relation in trincLfthdlral micna _

References cited .

Mg-Fe 41 relation in trioctahedral micas

Index

ILLUSTRATIONS

p»««

FkiUre 6. Relation between additional positive octahedral charges and negative charges available to neutralise them 17

7. Relation between additional positive octahedral charges and negative tetrahedral charges in excess of 1.00 18

8. Relation between octahedral occupancy and the number of additional octahedral positive charges due to tri-

valent and quadrivalent cations in trioctahedral micas 20

9. Relation between R+> cations displaced and proxying R+* (and R 4 ') octahedral cations _ 23

10. Distribution of trioctahedral micas with respect to the numl>er of additional positive octahedral charges carried

by trivalent and quadrivalent octahedral cations .... ... 24

11. Relation between Mg, Fe +, (Mn +1 ), and R +1 (A1, Fc 4I ,and Ti) in trioctahedral micas 25

12. Relation between chemical composition and geologic occurrence of trioctahedral micas 33

13. Relation between the composition and the geologic occurrence of biotites 38

TABLES

Page

Table 1. Calculation of structural formula 13

2. Average octahedral and tetrahedral cation content of formulas for phlogopites, Mg-doininant biotites, and Fe 4>

dominant biotites in order of number of additional positive octahedral charges ........ 19

3. Selected data on phlogopites from Holzner (1936, table 2) with added data for octahedral and total charge.... 22

4. Selected data on biotites from Holzner (1936, table 3) with added data for octahedral and total charge 22

5. Range in octahedral composition of phlogopites (in order of decreasing Mg content in terms of octahedral

positions) 26

6. Range in octahedral composition of biotites (in order of decreasing Mg content in terms of octahedral positions

occupied) 28

7. Average octahedral composition of biotites in order of decreasing Mg content 29

8. Formulas of representative siderophvllites 30

9. Formulas of representative lepidomelanes.. 31

10. Formulas of micas intermediate in composition between siderophvllites and lepidomelanea 32

11. Analyses and data for writing formulas of trioctahedral micas used in correlation study (in order of decreasing

MgO content) ... 41

12. Analyses and data for writing formulas of trioctahedral micas not used in correlation study (in order of decreasing

MgO content) ........ ..... ... ........ 46

ill

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

INTERPRETATION OF THE COMPOSITION OF TRIOCTAHEDRAL MICAS

By Margaret D. Foster

ABSTRACT

Structural formulas calculated for more than 200 published
analyses of phlogopites, biotites, sidcrophyllites, and lepido-
mclanos indicate that the additional positive charges carried by
trivalont cations proxying for bivalent Mg in the octahedral
group of trioctahcdral micas are accommodated in two different
ways, (1) by a positive charge on the octahedral layer, which is
neutralized by an equivalent increase in the negative tetrahedral
charge (increased replacement of Si by Al), and all the octahedral
sites are occupied, or (2) arc neutralized by negative charges
associated with unoccupied octahedral sites.

In almost all the structural formulas the octahedral group had
a positive charge and octahedral occupancy was less than 3.00,
indicating some degree of accommodation by both methods.
The degree to which accommodation is made by (1) or (2) varies
greatly. In general, however, there is a greater accommodation
by (2) than by (1) the greater the octahedral trivalent cation
content. As a result, there is also a general decrease in octa-
hedral occupancy with increase in octahedral trivalent cation
content. In most biotites, siderophyllites, and lepidomelanes
octahedral occupancy is significantly less than 3.00 sites — hence
they are not truly trioctahedral, nor are they octaphyllites. The
few formulas in which trivalent cations occupy more than one
octahedral site suggests that this is the essential limit of replace-
ment of R+> by R + * in these micas. It is also strong evidence
against the existence of a complete series between phlogopito
and muscovite.

Coincident with replacement of Mg by R +I , there is also
replacement of Mg by Fc M , ion for ion. With fow exceptions

the calculated formulas show both types of octahedral replace-
ment. But the two types, although coincident, are independent;
there is no relation between the amount of R* 1 present and the
amount of Fe +1 present. Neither type of replacement forms a
separate series, as a series of Fe +J only replacing Mg, of which
Winchcll’s annite is the theoretical end member. No repre-
sentative of this end member was found among the more than
200 analyses collected. On the evidence of the analyses and their
calculated formulas, an octrahedral occupancy of more than
2.20 positions by Fe +I is not to be expected.

The only trioctahedral micas in which more than 90 percent
of the octahodral positions are occupied by one species of cation
arc some phlogopites. From pure phlogopite as the prototype,
tho composition of all other trioctahodral micas may be derived
by replacement of Mg by, most commonly, Fe + * and R + > (Al and
Fe + *). In phlogopites the proxying of such cations for Mg is
minor, and Mg occupies more than 70 percent of the occupied
positions. Progressively greater proxying of these other cations
for Mg leads successively to Mg biotites, in which Mg is still the
dominant octahedral cation but in which Fe fl is present in
significant amounts, Fe +1 biotites, in which Fe +1 is the dominant
octahedral cation, with Mg present in subordinate but significant
amounts, and siderophyllites and lepidomelanes, in which Mg is
essentially absent, with Fe +1 the greatly dominant bivalent
octahedral cation and with significant amounts of aluminum and
(or) ferric iron. These relations are expressed in the following
formulas, which show the range in composition of the different
groups:

Phlogopite

Mg biotite
Fe +I biotite

Siderophyllites

and

lepidomelanes

<+0.30 <-1.00)-(— 1.30)

l(R<* jeP p <oj»Mgi. l »_j.o))(Sii,oi>-j.?oAli.o#-i jo)Oio(OH)j] _, .® ±, w K (Na,Ca/2)f<ii^*{o 10
3.00-2.84

<+0.60

(—1 .00)- (—1 .40)

[(Ih&-i.»F<^M-i.nMgi.7»-«.M)(8ij.»-j.»A! 1 ^-i js)Oi«(OH)j]~ , - m± *- w K(Na,Ca/2)+i)^, 0 o 1<

2.20-2.64

<+0.40 (-J.OO)-(l AO)

1(Bom-i o»Fpjj5-i.»)Mg<fi.uLiii.i})(Sij.ni-;,tiiAli.M)-i

2.90-2.65

Thus the trioctahedral micas can be considered members of a
complete system, at one end of which is phlogopite, with essen-
tially complete octahodral occupancy by Mg, and at the other
end of which is siderophyllite and lepidomeiane, with essentially
zero octahedral occupancy by Mg.

There is not a clear distinction in the composition of biotites
from different kinds of rocks. Biotites from different igneous
rocks, granites, diorites, granodiorites, nephelinc syenites may

be very similar in composition; on the other hand, biotites from
the same kind of rock may differ greatly in composition. Micas
at the extreme ends of the trioctahedral replacement system,
phlogopites and sideroph.vllites-lepidomelanes, which have
extremely high or extremely low Mg content, occur in more
extreme types of rocks, peridotites and other ultramafle rocks,
metamorphosed limestone, and contact zones of metamorphism
on the one hand, and pegmatites and greisen on the other.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

INTRODUCTION

This study of the compositional and layer charge re-
lations of the trioctahedral micas is an extension of a
similar study (Foster, 1950) of the composition and
layer charge relations of the dioctahedral potassium
micas. In that study it. was shown that these micas
may he classified and correlated on the basis of the re-
lation between the charges on their tetrahedral and
octahedral layers. It is the purpose of this paper to
present a similar interpretation of the composition and
layer charge relations of the trioctahedral micas.

LAYER CHARGE RELATIONS OF THE TRIOCTAHEDRAL
MICAS, THEORETICAL

Ideally, the layer charge relations of the trioctahedral
micas arc the same as those of muscovite, as expressed
in their theoretical or ideal formulas,

0.00 - 1.00

((Mg.Fc 4 , )j - (o(Sij.ooAli.(i))Oi»(OH)}J _ 10 # K, 4 ^i 00 ,
ooo -1.00

|Ah.o.(8i,^Al ljM )0 1 ,(OH),J-*-«Kji“.

In both of these formulas the octahedral group is neu
tral; all the inherent unit layer charge is on the tetra-
hedral group, owing to occupation of one-fourth of the
tetrahedral cationic sites by Al.

Few natural micas, however, have the exact compo-
sition specified by these theoretical or ideal formulas.
In the dioctahedral micas bivalent cations occupy some
of the octahedral positions ideally presumed to be oc-
cupied by Al, and in the trioctahedral micas some of
the octahedral positions, ideally presumed to be occu-
pied by bivalent ions like Mg or Fe + *, are occupied by
trivalent ions like Al or Fc +3 . Proxying of a bivalent
for a trivalent octahedral cation, ion for ion, in the
dioctahedral micas induces a negative charge on the
octahedral layer equivalent to the number of bivalent
octahedral cations. Constancy of charge and K con-
tent is preserved by an equivalent decrease in the
negative tetrahedral charge, that is, equivalent de-
crease in tetrahedral Al content and increase in Si con-
tent. These changes can be expressed by the equation,
+ nR +, + nSi— — 2nR +J . Replacement of one-half of
the trivalent octahedral rations by bivalent cations
produces the tetrasilicic end member of the trisilicic-
tetrasilicic series,

-1.00 0.00

I(R|.a»U|io)hii.o»0|o(OH)j)' ,- “K|.oo ao

in which all the inherent unit layer charge is on the
octahedral layer.

By analogy', proxying of a trivalent cation for a bi-
valent ion, ion for ion, in the octahedral group of a

trioctahedral mica should induce a positive charge on
the octahedral layer, which, for constancy of inherent
lay’er charge and K content, would require an equiva-
lent increase, in the negative tetrahedral charge and,
consequently, equivalently increased proxying of Al for
Si. This charge relation is assumed in Winchell and
Winchell’s (1951, p. 373) formulas (recast in the nota-
tion used in this paper) for castonite,

+0.4 -1.4

l (AU jMr 4 ) (Sij .1 Al 1 j) OiofOI I )i)“ K.ti 00
and siderophyllite,

+0.4 -1.4

[(Alo4Fe£j)(Sij,jAI,.t)Oio(OH)i|~ , - ro K, + Ji m

In these formulas it is also assumed that all 3 octahedral
positions are occupied, as they would be if the proxying
of trivalent for bivalent cations were 1 to 1 .

Holzner (1936, p. 435) noticed, however, that in for-
mulas calculated from biotite analyses, the number of
occupied octahedral positions is between 2.89 and 2.49;
in none of his formulas were 3.00 positions occupied.
To explain this low octahedral occupancy' he postulated
that biotite is intermediate between phlogopite and
muscovite in composition and that the crystal structure
is built up of the 2 mica types, most biotites approxi-
mating the composition of 2 of phlogopite to 1 of
muscovite, which yields a formula for biotite of:

0.00 -ICO

KAIo, t7 Mg,.(o) (Si4. w Al|. ro )0| t (OH)i)- 1 . ,t Kjjo”

Z«7

In this formula the tetrahedral group has the same com-
position and charge as it has in the ideal formulas for
pldogopite and muscovite, and the octahedral layer is
neutral, as in the theoretical or ideal formulas. The
0.67 additional positive charges carried by the 0.67
trivalent ions are neutralized by the 0.67 negative,
charges associated with the 0.33 unoccupied octahedral
positions.

Thus in Winchell's formulas for eastonite and sidero-
phyllite and in the formula suggested by Holzner for
biotite, trivalent octahedral ions are accommodated in
two quite different ways. In one the proxying of triva-
lent for bivalent octahedral ions is 1:1; all the octa-
hedral ca ( ionic positions are occupied ; and the additional
positive charges carried by the trivalent octahedral
ions form a positive charge on the octahedral layer
and are neutralized by' an equivalent increase in the
negative, tetrahedral churge owing to greater proxy'ing
of Al for Si. These relations are expressed in the
equation

(+2nR +3 ) = (— nR +2 )-K— nSi+<) (A)

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

In tho other way of accommodating trivalcnt octahedral
cations, 2 trivalent cations proxy for 3 bivalent cations.
There is, consequently, no increase in the number of
positive charges present, nor i9 there any change in the
layer charge relations, between the octahedral and
tetrahedral groups, but there is a decrease in the
number of octahedral positions occupied equivalent to
one-half of the number of trivalent octahedral cations.
These relations are expressed in the equation

(+2»R +8 )=(— 3nR + *) + (-n Oct. Pos.) (B)

In the first type of accommodation for trivalent octa-
hedral ions, the formula is characterized by full octa-
hedral occupancy, a positive octahedral charge, and a
negative tetrahedral charge greater than 1.00 by the
number of trivalent octahedral cations; in the second
type of accommodation the formula is characterized
by deficient, octahedral occupancy, a neutral octahedral
layer, and a negative tetrahedral charge very close to
1 . 00 .

ACCOMMODATION OF TRIVALENT CATIONS IN
NATURAL TRIOCTAHEDRAL MICAS

CALCULATION OF FORMULAS

For a study of the general characteristics of natural
trioctahedral micas and, particularly, their accommo-
dation of trivalent octahedral cations, structural
formulas were calculated from more than 200 analyses
of phlogopites, biotites, siderophvllites, and lcpidome-
lanes. The formulas were calculated by the method
devised by Marshal) (1949, p. 58) and modified by the
author (Foster, 1951, p. 728). The calculations in-
volved are illustrated by example in table 1. The
gram-equivalents of cationic constituents in the struc-
ture are obtained by dividing the percent of each con-
stituent present by a factor obtained by dividing the
molecular weight of that constituent by the number of
cationic valencies in its molecular formula. Thus for
FejOj the factor to be used is the molecular weight of
Fe 2 0,, 159.70, divided by 6, which is 20.617; for FcO
it is 71.85 divided by 2, or 35.925.

Table 1 . — Calculation of structural formula
| For 49, tuble 11)

Q raw* Cationic

(quit dent* talrncie s

of cationic per

Percent constituent* unit cell

Osi ions
per

unit cell

SiOi

..36.32-1- (60. 04-+-4) =

2. 419-1-0. 1109=

21. 912-1-4 =

5. 453
2. 547

tetra-

hedral

/ 8.000,

group

AljOj...

..14. 66-t-( 101. 96-i-6) =

0. 863-i-O.

1109 =

7. 781-1-3=

2. 594—0. 047]

TiO,. . .

3. 42-i- (79. 90-i-4) =

. 171-r- .

1109 =

1. 542-4-4 =

. 385

octa-

FejOj —

.. 4. 80-h( 159. 70-t-6) =

. 180-1- .

1109=

1. 623-i-3=

. 541

hedral

FeO__._

..14.74-t- (71.85-1-2) =

. 410-1- .

1109=

3. 697-1-2=

1. 818

group

MgO —

..12.38-1- (40.32-1-2) =

. 614-«- .

1109 =

5. 537-*-2=

2. 768

MnO

„ 0. 34-1- (70. 93-4-2) =

. 010-1- .

1109=

. 090-1-2=

. 045 j

Charge

-2. 547

+ a 630

Sum (—Si and Al) 12.480 5.634 (octahedral 1. 917 (composite

Octahedral Al cations X 3— * . 141 == occupancy) layer charge)

+ 12. 630
- 12. 000

+ 0. 630 (octahedral
charge)

CaO Trace

Na,0 0.90-1- (61. 98-4-2) = 0. 029-4-0. 1109“ 0. 261-4-1= 0.261

K,0 8.63-4- (94. 20-1-2) *= .183-4- . 1109= 1.650-4-1 = 1.660

HjO.

4.879 1.911

4. 879-4-44 = 0. 1109

2. 72

Structural formula (half-cell)

+0.77 -1.27

l(Alo.«Tio.i»Fe^ 2 ’fe^M8i jfMn^M)(Sij.nAli.ir)Oii)(OH)j) _ln<, (K»JJ>^' a «.u^o.M* i

ISO

1.911 (interlayer
= -_—■= cationic
charge)

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8H0RTER CONTRIBUTIONS TO GENERAL GEOLOGY

The second step in the calculation is to convert
grain-equivalents of the cationic constituents to cationic
valencies in the unit cell. As the number of cationic
valencies must be the same as the number of anionic
valencies present, the number of cationic valencies
present is usually based on the number of anionic
valencies furnished by the HjO-f and F reported in the
analysis. However, in many of the analyses insufficient
data were given for this; in some F was not reported, in
others plus and minus waters were not reported, only
total water, and in still others the H,0-f and F together
were much too low. The formulas were, therefore, all
calculated on the basis of the cationic and anionic
valence content of the idealized unit cell, 44. The sum
of the gram-equivalents of the cationic constituents
was, therefore, divided by 44 to obtain the factor for
converting them to cationic valencies per unit cell.
After dividing the gram-equivalents of each cationic
constituent by this factor, the number of valencies per
unit cell thus obtained of each cation is then divided by
its valence to obtain the number of cations per unit cell.

The aluminum cations are divided between the
tetrahedral and octahedral groups; enough A1 is allo-
cated to the tetrahedral group to bring the total, with
silicon, to 8.00, and the remainder is assigned to the
octahedral group. The sum of the cations in the
octahedral group should, theoretically, be 6.00, but in
most of the calculated formulas for trioctahedral micas
it is less than 6.00.

Throughout this paper the discussion is based on the
half-cell formula. To write the half-cell formula, the
values for the cations and charges per unit cell are
merely halved, as in the formula at the bottom of table
1 . Attention is called to the order in which the groups
and cations within each group in the formula are
written. First the octahedral group (enclosed in
parentheses) is noted, with the cations in that group
written in order of decreasing valence, except for Ti,
which is written after Al. Then the tetrahedral group
(also enclosed in parentheses) is noted, with Si, the
principle cation, written first. Above each group its
charge is noted. After these two groups, which indi-
cate the cationic composition, the anionic composition,
Oi 0 (OH) 2 , is written; and the whole is bracketed, as
indicating the composition of the composite layers.
After the upper part of the closing bracket, the total
negative charge on the composite layer unit is written.
This is followed by a notation of interlayer cation con-
tent, with the positive charge carried by these cations be-
ing written at the top of the closing parenthesis, and the
number of positions occupied by these cations at the
bottom. The interlayer cations are written last,
rather than first, the more conventional position,
because the amount and charge of the interlayer cations

is dependent on and must neutralize the charge on the
composite layers.

Theoretically 32 of the 44 anionic or negative
charges are allocated to the tetrahedral group and 12
to the octahedral group. Thus if the tetrahedral group
is entirely made up of Si cations, which are quadri-
valent, the number of positive charges present is
exactly equal to the number of negative charges,
4X8=32, and the tetrahedral layer is neutral. But
if the tetrahedral group contains some Al, which is
trivalent, there are not enough positive charges to
neutralize all the negative charges present and the
tetrahedral layer has a negative charge. Thus in the
example given in table 1, the tetrahedral group contains

5.453 Si cations and 2.547 Al cations, which carry

29.453 positive charges, and the tetrahedral layer has
a negative charge of 2.547, exactly equal to the number
of Al cations in that layer. If all the 6 octahedral
positions in the unit cell of a mica are occupied by
bivalent cations, as by Mg in phlogopite, the 12 positive
charges they carry exactly equal the 12 negative charges
allocated to that layer, and the layer is neutral; but if
some of the positions are occupied by trivalent ions,
the octahedral layer may have a positive charge, even
though all the octahedral positions are not occupied,
as in the example given in table 1. The number of
positive octahedral charges present is calculated by
multiplying the number of cations of each constituent
by its valence and by adding these together. More
simply, the same result can be obtained by taking the
sum of the gram-equivalents per total of 44 of all the
octahedral cations except Al cations and adding to this
the number of octahedral Al cations (from the column
headed cations per unit cell) multiplied by 3, as is
shown in table 1. If this number, as in the example
given, exceeds 12.000, the octahodral layer has a posi-
tive charge equal to the excess; if it is less than 12.000,
the octahedral layer has a negative charge.

The algebraic sum of the tetrahedral and octahedral
charges is the inherent charge on the unit layers and
should closely agree with the charge on the interlayer
cations, as it does in the example given. The nega-
tive inherent charge on the unit layers and the posi-
tive charge on the interlayer cations should be close
to 2.00 (1.00 in the half-cell formula) for trioctahedral
micas like the phlogopites and biotites. In evaluating
the half-cell formulas used in this study, a variation
of plus or minus 0.1 (0.2 in the unit cell) was permit-
ted in these values. Formulas, in which cither the
negative inherent charge on the unit layers or the pos-
itive interlayer cation charge, or both, were greater or
less than 1.00 by more than 0.1, were not used in the
study. This was done in order to exclude from the
study the formulas that may represent hydrous micas,

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

in which the interlayer cations are generally lower than
in true micas, or, possible contamination of trisilicic
trioctahedral micas with other materials.

The role of titanium in micas is ambiguous. Appar-
ently no studies have been made to determine whether
or not the titanium reported is actually in the mica
structure. In some micas discrete crystals of rutile
can be discerned, but what proportion of the total
titanium content these represent is not known. In
other micas discrete crystals of rutile are not discern-
ible, and the color of the micas suggests that the
titanium is in the layer structure. For some analyses
used in this study, formulas were calculated as if all
the titanium were in the layer structure and as if none
of the titanium were in the layer structure. These
calculations showed that for the amount of titanium
usually reported, the inclusion or exclusion of titanium
in calculating the formula has only a slight effect on
the number of positions occupied by other octahedral
cations. In accordance with general usage, therefore,
titanium was included in the octahedral group in cal-
culating the formulas herein used. The analyses (and
data from which their calculated formulas may be
written) that were used in the study are given in
table 11; the excluded analyses (and data from which
their calculated formulas may be written) are given
in table 12.

EXCLUDED ANALYSES AND FORMULAS

Exclusion of certain analyses and formulas from the
Btudy does not necessarily indicate that they repre-
sent poor specimens or poor analyses. Many of the
formulas in which the negative inherent unit layer
charge and the positive interlayer cation charge is les9
than 0.90 represent very high magnesium trioctahedral
micas, that is, phlogopites. In addition to their low
inherent unit layer charge and low interlayer cation
charge these formulas are, in general, character-
ized by a positive octahedral layer charge greater than
the number of extra positive charges carried by their
trivalent octahedral cations, and by a high octahedral
occupancy, many of the formulas having an octahedral
occupancy greater than 3.00. These characteristics
indicate the allocation of too many cations to the
octahedral layer, and too few to interlayer cation posi-
tions. Reallocation of some octahedral cations in these
formulas to interlayer positions would produce more
rational formulas.

For many years it was customary in calculating for-
mulas from analyses of montmorillonite, which has the
same structure as the micas, to allocate all the Mg to
the octahedral group. The result was that in most
formulas for montmorillonite the number of occupied
octahedral positions was greater than 2.00, up to 2.24,

027919—69 2

and Ross and Hendricks (1945, p. 44) concluded that
in montmorillonite more than 2.00 octahedral positions
were characteristically occupied. However, the writer
(Foster, 1951, p. 725) determined the exchangeable
cations in a number of montmorillonites and found
that they all contained some exchangeable Mg, and
that when only nonexchangeable Mg was allocated to
the octahedral layer, the number of octahedral posi-
tions occupied wa9 2.00 ±0.02 in the same specimens
that apparently had as many as 2.12 octahedral posi-
tions occupied when all the Mg was allocated to the
octahedral group.

These facts indicate that Mg can occupy interlayer
positions and suggest that in the highly magnesium
micas mentioned some of the magnesium should be
considered as occupying interlayer positions. For
example, if all the MgO, 24.60 percent, analysis Dl5,
table 12, is allocated to the octahedral group in the
usual way, the positive octahedral layer charge is 0.44,
whereas only 0.32 additional positive charges are carried
by the trivalent octahedral cations present; an excessive
number of octahedral positions are occupied, 3.06 ; the
inherent unit layer charge is only —0.82; and the inter-
layer cation charge in only +0.83. If, however, 0.75
percent of the MgO is allocated to the interlayer cations
the positive octahedral layer charge is 0.28, 0.04 less
than the number of positive charges carried by the
trivalent octahedral cations present, 2.98 octahedral
positions are occupied, the inherent unit layer charge
is —0.98, and the interlayer cations charge is 0.99. A
comparison of the two formulas,

*t*0 .44 —j

((Alo.nTio.wFeiJol, (Sij.jjAii j»)Ou(OH)a] -0J1

3.08

(K,Na,Ba/2) 0 + i, M

« •

+ .28 -1.38

[(Alo »Ti«.otf'eaotr , aiMtMg>j>)( Si|.nAli,M)On(OII)>} _0H

2.98

(K,Na,Ba/2,Mg/2)» + ,y®

shows that the only change in layer occupancy is in
the number of octahedral positions occupied by Mg;
the number of positions occupied by all the other
cations, in both the octahedral and tetrahedral layers,
is the same in both formulas. Therefore, if Mg does
occupy interlayer positions in micas, analyses like this
group which contain considerable Mg and in which the
negative inherent layer charge and the positive inter-
layer cation charge are low, may not be faulty, or
represent poor materials, but may simply represent
trioctahedral micas in which some of the Mg occupies
interlayer positions.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Another group of formulas was excluded from the
study because their negative inherent unit layer charge
and their positive interlayer ion charge was greater
than 1.10. In formulas calculated from analyses in
which lithium was not determined the high unit layer
and interlayer charges may be due to the failure to
separate lithium from sodium. Failure to separate
lithium from sodium has a double effect on the formula
calculation, as it is reported as sodium and is calculated
as an interlayer cation rather than as an octahedral
cation. Thus, in the formula the interlayer cations
and their charge are high, the octahedral cations and
the positive octahedral charge are low; and, conse-
quently, the negative inherent unit layer charge is
high. This double effect is shown in tho formulas
below for D58, table 12,

+ 0.31 — 1 .54

|(AU. M Tt 1 . w Fe,tAKe,^M8».,,Mu^, a «)( 8i rM AI, J ,Fc a 4 i,)0,,(0n)d- * 1 ^

Z57

(K,Na,Ca/2)£&* 4

+0 .50

((AlnooTiftMFe^i&Fe^Mgo.uMno^HLis.M)

Z87

- 1.45

(Si 1 . u Al I . M F^)0,o(OH), ]-♦■•* (K, Na, Ca/2 )}$»

In the first formula, which is calculated from the
analysis as reported, the negative inherent layer charge
and the positive interlayer cationic charge are very
high, but the octahedral occupancy is quite low. The
second formula is a recalculation from the same analysis
on the assumption that the Na 2 0 reported contained

1 percent of LijO. The formula content of other cations
present is very little changed, but the octahedral
occupancy is raised from 2.57 to 2.87, and the negative
unit layer charge and the positive interlayer cation
charge are reduced to 0.99 and 0.98, respectively.
Thirteen of the eighteen formulas that were not used
because of high unit layer charge and high interlayer
cation charge were of the type most likely to contain
lithium, high in Fe +S and very low in Mg. Thus,
although high unit layer and interlayer cation charges
may be due to faulty analysis, particularly in determina-
tion of the alkalies, it is also possible that a calculated
formula may show such high charges because of the
analyst’s failure to separate sodium and lithium.
Failure to separate and determine Rb and Cs may also
contribute to an apparently high alkali content.

In calculating the formulas for several analyses pub-
lished as analyses of phlogopites or biotites, it was found
necessary to allocate all the Al 2 O a , all the Fe 2 0 2 , and

some of the TiOj to the tetrahedral layer to complete
the filling of that layer, and in one phlogopite analysis
it was necessary to assign all the Al a O a , Fe 2 O a , Ti0 2 , and
FeO to the tetrahedral layer, leaving only MgO and a
little Li a O in the octahedral layer — even so, the octa-
hedral occupancy was high, 3.08 positions. All such
analyses and formulas were excluded from the study
as not representing the general chemical composition
of trioctahcdral micas, the subject of this study, whether
or not the analyses themselves may be faulty or may
represent contaminated materials.

Two other small groups of analyses with their derived
formulas that were excluded from the study were not
representative of the kind of micas under consideration.
In one group the K content was very low, occupying
fewer than 0.75 positions, with relatively high Ca
and (or) Na content; in the other group the octahedral
trivalent occupancy was very high, greater than 1.50,
and total octahedral occupancy was very low, less than
2.50 positions. In several of the latter group the tri-
valent octahedral cations made up more than 65 per-
cent of the octahedral cations. In one analysis, D61,
table 12, which has 19.49 percent of Fe 2 O a , and 14.10
percent of FeO, Clarke (1903, p. 77) suspected altera-
tion. A later analysis showed 24.22 percent of Fe a O*
and 13.11 percent of FeO. Another analysis reports
27.19 percent of Fe 2 0»with only 0.64 per cent of FeO.
In the formula for this analysis bivalent cations occupy
less than 30 percent of the occupied octahedral positions,
all the rest are occupied by trivalent cations. In
analyses that yield formulas with unusually high octa-
hedral A1 content, contamination with muscovite may
be suspected. For example, the material represented
by one analysis was obtained from arborescent aggre-
gates of biotites wdth muscovite occurring in the ter-
minals of the aggregates.

ACCOMMODATION OF EXTRA POSITIVE OCTAHEDRAL

CHARGES IN MICAS STUDIED

In a few of the formulas included in the study, the
proxying of trivalent for bivalent octahedral cations is
in accordance with equation A, (+2nR + *)=(— »R +1 )
+ (— nSi* 4 ), as in the following formula for a mica from
Russia (26, table 11),

+0.34 -1.33

KAh.,,Ti,.»F«&Fc&Mgi.») (S i..«7Al, , o )0„(0H),)-«»

3.01

(Ko.: < .Na<i.i(Ca/2 c .M)a5i® 7

In this formula the proxying of trivalent for bivalent
ions is 1:1, 0.26 Al, Ti, and Fe +1 ions proxy for 0.25
R +1 ions, and all the octahedral positions are occupied.
The additional positive charges carried by Al, Fe +S , and
Ti form a positive charge of 0.34 on the octahedral

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

layer, which is neutralized by an equivalent increase in
the negativo tetrahedral charge. On the other hand,
a few formulas exhibit the type of accommodation for
trivalent octahedral ions expressed by equation B,
(+2«R +, )=(— 3nR +s )-f(— nOct. Pos.), as does this
formula for a biotite from L&vcn Island (84 table 11),

+0.04 -1.07

[ (Alo., t TU. M Fe 0 + , , 8 Pe7i,Mg4.MM no + 3 > ) (Si,. w AI,.i n )O l ,(OH),l- |W

2.78

(K.j,Na,

In this formula the proxying of trivalent for bivalent
octahedral cations is approximately 2:3; 0.42 Al, Ti,
and Fe +S cations carrying 0.46 additional positive
charges proxy for 0.63 R +1 cations, and 0.21 unoccupied
octahedral positions furnish 0.42 negative charges to
neutralize 0.42 of the additional positive charges.
The octahedral layer is, therefore, almost neutral,
having a positive charge of only 0.04; and the tetra-
hedral charge is 1.07, close to the 1.00 of the theoretical
formula. However, most of the formulas calculated
for this study are characterized by both a positive octa-
hedral charge and a deficiency in octahedral occupation;
this indicates a dual adjustment, as in this formula for
a phlogopite from Uganda, 33, table 11,

Fwbk 8.- Rdlntlon bctwwn »ddltlniial positive octahedral ehantw and nognttvo
charges available to neutralise them.

+ SO -1 .29

KAle.toTie.itFeQ^Peo^Mfo.HMne.iaR Sir.nAli j>)Oio(OH)>)~ iw
US

(Ko.».Nao.ej,C&/2o.oiB a /2(>.e4)a«^ 4

In this formula the trivalent and quadrivalent octa-
hedral cations carry 0.52 positive charges in excess of the
number of positive charges carried by the same number
of bivalent cations. Of these additional charges, 0.30
are neutralized by 0.15 unoccupied octahedral positions
and 0.22 form a positive charge on the octahedral layer,
which is neutralized by an increase in the negative
charge on the tetrahedral layers. The inherent layer
charge is, consequently, very close to 1.00 (1.07), and
is balanced by interlayer cations, K, Na, Ba, and Ca,
carrying an equivalent positive charge.

As illustrated by this example, in dual accommoda-
tion for trivalent and quadrivalent octahedral cations
in trioctahedral micas, the additional positive octa-
hedral charges are neutralized by the negative
tetrahedral charge in excess of 1.00, in accordance with
equation A, and by the negative octahedral charges left
available by unoccupied octahedral positions, in accord-
ance with equation B. Theoretically, the sum of these
negative charges should exactly equal the number of
additional positive charges carried by the trivalent and
quadrivalent octahedral actions. This relation in the
trioctahedral micas studied is shown in figure 6, in
which the number of additional positive charges carried

by trivalent and quadrivalent octahedral cations in
each formula is plotted against the number of negative
charges available to neutralize them; that is, the sum
of the tetrahedral charge in excess of —1.00 plus the
number of unoccupied octahedral positions doubled.
Points for formulas in which the number of additional
positive octahedral charges is exactly equal to the
sum of negative charges available fall on the line
bisecting the figure. Location of a point above or
below the line indicates that in the formula represented
by the point the negative charges available are greater
or less, respectively, than the number of additional
positive octahedral charges, by the distance of the
point from the line. The close clustering of the points
along the line indicates that there is a fairly close
agreement in the formulas between the number of
additional positive octahedral charges and the number
of negative charges available to neutralize them The
points on or close to the line represent formulas in
which the inherent unit layer negative cliarge and the
interlayer cation positive charge is almost exactly 1.00.
Those farthest from the line represent formulas in
which the inherent unit layer negative charge and the
interlayer cation positive charge is near 0.90 or 1.10.
In the formulas in which the inherent unit layer nega-
tive charge and the interlayer cation charge is less than
1.00, the tetrahedral negative chaige in excess of —1.00
is less than the octahedral positive charge ; in formulas

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

in which the inherent layer negative charge and the
interlayer cation positive charge is greater than 1.00,
the tetrahedral negative charge in excess of —1.00 is
greater than the octahedral positive charge. As
pointed out in the discussion on the calculation of
formulas (p. 13), these discrepancies may be due to
analytical error, particularly in the determination of
Ca, Na, and K, to failure to determine Li or CO», or to
the use, in calculating the formulas, of the theoretical
oxygen and hydroxide, fluorine values (O l0 (OH,F),)
because of lack or obvious inaccuracy of data on these
constituents in the analyses.

The degree of accommodation for additional positive
octahedral charges by each of the two methods in the
trioctahedral micas under study is shown (fig. 7) by
plotting, for each formula, the additional positive
octahedral charges against the number of negative
tetrahedral charges in excess of 1.00. Points for

Fjqurx 7. Rotation between additional positive octahedral charges and negative
tetrahedral charges In excras of 1.00.

formulas that exhibit accommodation for trivalent and
quadrivalent octahedral cations exclusively in accord-
ance with equation A fall on line A, those for formulas
that exhibit accommodation for trivalent and quadri-
valent octahedral cations exclusively in accordance with
equation B fall on the ordinate, and those for formulas
exhibiting both types of accommodation for trivalent
octahedral cations fall between these two lines. The
location of most of the points between these two lines
makes it quite apparent that in most of these tri-
octahedral micas both types of accommodation for
trivalent and quadrivalent octahedral cations are repre-
sented. In formulas represented by points near the
middle of the area between lines A and B, accommoda-
tion has been made both ways about equally; in formulas
represented by points closer to line A or to the ordinate
of the graph, line B, that type of accommodation repre-
sented by line A or line B was made to a greater degroo
than by the other type.

The average adjustment in trioctahedral micas for
different amounts of additional positive octahedral
charges due to trivalent cations is shown by the average
formulas in table 2. To arrive at these average formulas
the calculated formulas used in this study were grouped
according to the number of additional positive charges
carried by their trivalent (and quadrivalent) octahedral
cations. If the formula contains no Ti, the number of
additional octahedral positive charges is equivalent
to the number of octahedral positions occupied by
trivalent cations, usually A1 and Fe +S . But if the
formula contains Ti, the number of positions occupied
by Ti must be multiplied by 2, as Tr*" 4 carries 2 more
charges than a bivalent cation, and this number is
added to the number of octahedral positions occupied
by trivalent cations. For example, in tbe formula for
No. 33, table 1 1 , trivalent cations occupy 0.22 octahedral
positions and Ti occupies 0.15 octahedral positions.
Thus the number of additional positive octahedral
charges present is 0.22 + (0.15X2) =0.52. From the
formulas in each of these groups, separate average
formulas were derived for the magnesium and for the
bivalent iron-dominant micas when both are sufficiently
represented in a group. However, sufficient numbers
of formulas to permit derivation of average Fe + *-
dominant formulas are found only in the groups in
which the number of additional positive charges is
greater than 0.50. In only three Fe + *-dominant for-
mulas were the number of additional positive charges
carried by trivalent and quadrivalent octahedral cations
less than 0.50. On the other hand, Mg-dominant
formulas are found in all the groups, and from these
the general mode of adjustment of trioctahedral micas
to the presence of trivalent and quadrivalent cations
in the octahedral layer can be deduced.

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INTERPRETATION OF TRIOCTAHEDRAL MICAS 19

Tablx 2. — Average octahedral and tetrahedral cation content of formulae for phlogopitee, Mg-dominanl biotitee, and Ve +, -dominant biotitee

in order of number of additional poeilive octahedral chargee

Oroup

Number of
additional
positive
octahedral

charges

Number of
formulas

Mg-domlnnni formulas

Number of
formulas

^•■-dominant formulas

0. 00-0. 10

+0.05 -1.00

( A1«.m F«ouo» Foibos Mgj .*) (Sis .te A1 1 M )
3.00

None

0.05

0. 11-0. 20

+0.16 -1.15

(Als.ioF c^ojF «o + I'oMgj.jj) (Si,. u Ali.u)

None

0.15

300

0. 21-0. 30

+0.26 -1.26
(AJe.iiFe^ 1 , 0 Feo^i)Mg,. a ) (Sij.j 4 Al 1 . 4 t)

None

0.26

300

0. 31-01 40

+025 -1J5

(Ale.iiTie. M Fe^*oFeo!iMg).s») (Sij., s Ali. u )

0.35

2.05

0. 41-0. 50

+025 -125

( Ale .uTio mF Colo Fe^w Mgi.si) (Sij .u Ali.u)

0.45

zoo

0. 51-0. 60

+0.25 -125

(AlojoTie. 1 eFea* 6 Feo)MMgi.j»)( 8 is.j»Al|.js)

+024 -1.25

(Alo.ioTle.uFeo) 1 J 4 Fe^.iMgo.*e)(Si,,7,Al|.i t )

0.66

2AS>

7JU

0. 61-0. 70

+0.25 -125

( Alo.uTifl.isFeoJoFeo!*) Mgi.se) (Sit. uAli.ss)

+025 -124

(AJs.ijTio.i,!' e^JoFe^tsMgs.ss) (Sit.ts All .«)

0.65

220

2.80

0. 71-0. 80

+0.25 r -125

(Als.s»Tie.itFea'j 4 Feo4jMgi,to)(Sij.riAli jj)

+0.25 -123

(Ale.»Tio.ieFeo^jjFei f 3sMg8.u)(Sij.tjAli.tj)

0.75

226

2.75

a 81-0. 90

+0.25 -125

( Al« ,tsTio.jeFe^» Fe^«o Mgi .u) (Sh .is Alt js)

+024 -1.25

(Alo.uTio.uFeo'iFei + j 4 Mgo7») (Sij.jsAli m)

0.85

2.70

The average Mg-dominant formulas indicate, in
general, that if the number of additional positive charges
carried by trivalent and quadrivalent octahedral cations
is less than 0.25, all the additional positive charges form
a positive charge on the octahedral layer, the negative
tetrahedral charge is greater than 1.00 by an amount

equivalent to the positive octahedral charge, and all the
octahedral cationic positions are occupied; that is,
adjustment for the additional positive octahedral
charges is predominantly in accordance with equation
A. Thus the average formula for group A, in which the
average number of additional octahedral positive

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

charges is 0.05, has a positive octahedral charge of 0.05,
a negative tetrahedral charge of 1.05, and all the octa-
hedral positions are occupied. Similarly in the average
formulas for groups B and C, in which the average
number of additional positive octahedral charges is

0. 15 and 0.25, respectively, the positive charge on the
octahedral layer is equivalent to the number of addi-
tional positive charges carried by R +3 octahedral
cations, the negative tetrahedral charge is greater than
1.00 by an equivalent amount and all the octahedral
positions are occupied. In the average formula for
group D, however, in which the number of additional
positive charges carried by R +3 (and R" 1 "*) octahedral
cations averages 0.35, only 0.25 of these extra charges
form a positive charge on the octahedral layer — the
remaining 0.10 charges are neutralized by the 0.10
negative charges associated with the 0.05 unoccupied
octahedral positions. In succeeding group formulas the
increasingly greater number of additional positive
charges is reflected not in greater positive charges on
the octahedral layer and greater negative tetrahedral
charges but in greater nonoccupancy of octahedral
positions, that is, an increasingly greater proportion of
the adjustment for trivalent and quadrivalent octa-
hedral cations is made in accordance with equation B.
Thus, in the average formulas for groups E, F, G, H, and

1, the average positive octahedral charge is the same,
0.25, but the average number of octahedral positions

occupied progressively decreases from 2.90, in formula
E, to 2.70, in formula I.

These relations between positive octahedral charge
(equation A) and octahedral occupancy (equation B)
with increase in the number of additional positive octa-
hedral charges suggest that the amount of positive
charge on the octahedral layer that can be accommo-
dated comfortably by the structure is somewhat limited,
and that with a greater number of positive octahedral
charges to be neutralized, neutralization by negative
charges associated with unoccupied octahedral positions
is generally more tolerable to the structure than neutral-
ization by a greater negative tetrahedral charge and the
necessarily greater proxying of A1 for Si. Throughout
the range there are, of course, some formulas that
deviate greatly from the average in their mode of adjust-
ment (fig. 7) but the average formulas illustrate the
general way in which different amounts of additional
positive charges carried by trivalent octahedral cations
are accommodated in the trioctahedral micas.

The general decrease in octahedral occupancy with
increase in the number of additional positive octahedral
charges is shown graphically in figure 8. In this figure,
for each formula, the number of occupied octahedral
positions is plotted against the number of additional
positive charges carried by trivalent (and quadrivalent)
octahedral cations. If three octahedral positions were
generally occupied in the trioctahedral micas and if

Pioure 8.— Relation between octahedral occupancy and tbe number of additional octahedral positive char*ee due to trivalent and quadrivalent callous In trioctahedral mlcaa.

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INTERPRETATION OP TRIOCTAHEDRAL MICAS

accommodation for trivalent octahedral cations were
generally made according to equation A, the points
representing the extra R 4 * charge-octahedral occu-
pancy relation of the formulas would fall in a narrow
horizontal band across the top of the figure. The
general trend of the points diagonally downward from
left to right indicates a general decrease in octahedral
occupancy with increase in the number of additional
octahedral positive charges due to some degree of
adjustment for these additional charges in accordance
with equation B. The width of the band indicates the
variation in the degree to which adjustment for triva-
lent and quadrivalent octahedral cations is made in
one way or the other. Formulas having quite different
amounts of additional R 4S (and R +< ) positive octahedral
charges may have the same octahedral occupancy, and
vice versa, depending on the degree to which accom-
modation for additional R 41 (and R +4 ) positive octa-
hedral charges has been made in accordance with
equation A or equation B. For example, the formulas
for analysis 84, table 11,

+0.04 -1.07

( (AU.ioTio.^Fc^j^clt^Mgo.nM n^,) (Si i ,nAli. J 7)Oio(OH) t ]- | -° l
2.79

(K^Na^OJA 0 *

and for 109, table 11

+0.45 -1.42

[(Ai«, w Ti,. B Fe B 4 j5,FeaM8..«)( Slij«AI,.u)O w (OH),l-«-n

2.79

(Ko.j»,Nao.u,Ca/2o.cj )o.Si*

differ greatly in the number of additional R + * positive
charges present, 0.46 and 0.87, respectively, and in
positive octahedral charge but have the same octahedral
occupancy. In the formula for 84 accommodation for
R 4S (and R 44 ) cations has been made almost entirely
in accordance with equation B, 0.42 R 4 * (and R 44 ) ions
proxying for 0.63 R 4 * ions, whereas in the formula for
109 accommodation has been made almost equally by
both methods. Of the 0.87 additional positive charges
carried by the R 48 (and R + ‘) octahedral cations present
in the formula for 109, 0.45 form a positive charge on
the octahedral layer and are neutralized by an approxi-
mately equivalent increase in the negative tetrahedral
charge, and 0.42 are neutralized by the 0.42 negative
charges associated with 0.21 unoccupied octahedral
positions. The formulas for analyses 36,

+0.05

[(AU.iiTia.«Fc < ^ l \Cr < ^oi FcixA Mgi .?»MiioA I. ip a )

2.78

-1.18

(8i>4BAli.ii)Oio(OH)j] -I - ,, (K».Ti,Na«.ii,Ca/2o,ij)^A u

and 96, table 11,

+0.54 —1.34

[(AU. W Ti,. w F ao tj5 i Fe^Mg,,nMn 0 + A ) (Su.uAl, .^OwfOH),]-*"

2.91

(K 0 . B ,Na a . u ) l + A“

have the same number of additional R 48 (and R 44 )
charges, 0.51 and 0.52, respectively, but differ greatly
in octahedral occupancy, in positive octahedral charge,
and in negative tetrahedral charge. In the formula for
36, accommodation for R +J and R 44 octahedral cations
has been made predominantly in accordance with
equation B, with 0.45 R 48 and( R +4 ) cations proxying
for 0.68 R +! cations; in the formula for 96 about two-
thirds of the accommodation for R 48 (and R +4 ) octa-
hedral cations is in accordance with equation A, and
one-third in accordance with equation B.

Thus the vertical location of a point in figure 8
depends on the manner in which octahedral R 48 (and
R 44 ) cations have been accommodated in the structure.
Points near the top of the diagonal band represent
formulas of individuals in which the accommodation
was predominantly in accordance with equation A;
points near the bottom of the diagonal band represent
formulas of individuals in which accommodation was
predominantly in accordance with equation B. The
width of the diagonal band indicates, therefore, the
degree of variation in the manner in which the triocta-
hedral micas represented by the points have accom-
modated themselves to the presence of trivalent
octahedral cations. However, despite such variations
in manner of accommodation, it is quite obvious, from
the average formulas in table 2, and from the down-
ward trend of the band in figure 8, that there is, in
the trioctahedral micas, a general decrease in octahedral
occupancy with increase in octahedral trivalent cations.
The trioctahedral micas are, in general, therefore, not
strictly trioctahedral, nor are they strictly octaphyl-
lites, as they contain fewer than eight cations per
half cell.

Although Holzner (1936, p. 435) noted deficiency
in octahedral occupancy in his biotite formulas and
attempted to account for it by postulating that the
biotite structure is made up of 2 layers of phlogopite
to 1 of muscovite, he apparently failed to notice that
in his formulas tetrahedral aluminum and conse-
quently, tetrahedral charge, is, with but 2 exceptions
(21 and 30, table 4) greater than 1.00, ranging from
1.01 to 1.40. On the other hand, the K(Na,Ca)
values are, with but five exceptions, lower than the
corresponding tetrahedral A1 values. As the number
of interlayer cations present is dependent on, and is
usually equivalent to, the inherent layer charge, this
discrepancy between Holzncr’s Al[4] (which represents
the tetrahedral charge) and his K(Na,Ca) values

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8H0RTEB CONTRIBUTIONS TO GENERAL GEOLOGY

suggests that the octahedral layer in his formulas
must carry a positive charge approximately equivalent
to the difference between his Al[4] and K(Na,Ca)
values. As Holzner included in his tables II and III
the octahedral bivalent (Y") and trivalent (Y'")
ion content, it is possible to calculate from them the
octahedral charge and the inherent layer charge of
his formulas. The results of these calculations are
given in tables 3 and 4, together with Holzner’s values
for Y", Y'", Y ,/ +Y / " (equivalent to octahedral
occupancy), Al[4] (equivalent to tetrahedral charge),
and K(Na,Ca). All but five (2, table 3, and 13, 18,

Table 3. — Selected data on phlogopites from Holzner (1936, table f)
with added data Jot octahedral and total charge

No. of

analysis

y ///

Y"+Y"'

Octa-

hedral

charge

Aim-

Totra-

bcilral

charge

Total

charge

3. 031

3.031

+(Yf»Y2

-1. 127

-1.065

1.077

2.906

0 wo

2 020

-,i»

—1.048

-1.177

1.180

2. 831

.053

2.9M

r.02l

-1.134

-in*

I.OM

2.843

.0*2

2 925

-.M

-1. 158

-1.0M

1.077

2.015

.W2

3.007

-.106

-1.086

-.990

.9*5

2 801

.122

3.013

-.148

-1 148

-1.000

.993

.107

3006

-.XI7

-1 155

— . 94S

.930

2 005

2 001

•ocw

-1 223

-1.215

1.210

ZHV

.223

3 032

-.W 7

-1 001

-.804

.704

2 077

.26*

2 045

-.1 M

-1.217

-1.059

1.W6

2 657

.270

2027

-.124

-1.190

-1. 066

1.1*4

12.

2 755

.280

3 035

-.350

-1 323

-.973

.993

2687

.287

2 984

-.235

-1.134

-.899

.878

2 675

,3l<5

2 078

-.259

-1.177

-.918

.821

.337

2 903

-.323

-1.110

-.787

.783

.*»

2 040

-.230

-1.170

-.94(1

.942

2 651

. 3!0

2 001

-.352

-1.290

-.938

.938

2 549

.3W

290*

-. 175

-1.180

-1.005

1.002

2 516

2973

-.404

—1. 288

-.884

.888

2 420

.4»

2 916

h 328

-1.332

-1.004

1.004

Table 4. — Selected data on biotitee from Holzner (1936, table 3)
with added data for octahedral and total charge

NO. Of
analysis

y«/

Y"+Y"'

Octa-

hedral

charge

AIM-

Tetra-

hedral

charge

Total

charge

2.402

0.418

2820

+0.058

-1. 186

1.078

-1.128

2.358

.490

2857

K 213

-1.232

1.016

-1.019

2. 162

.654

2816

-.286

-1.203

.922

-.917

2.307

.533

2 840

K 213

-1. 109

. 951

-.956

1015

.791

2806

b 403

-1.880

.881

-.927

Z 160

.614

2783

-.180

-1.251

.907

-1.071

Z 190

.614

2.804

-.222

-1.254

-1.032

2.040

. 681

2721

-. 123

-1. 140

.992

-1.017

2.508

.356

2864

K 084

-1.114

.940

-1.030

2.315

.538

2853

b 244

-1.242

.967

-.90S

2290

.695

2.894

-.383

—1.896

1.013

-1.013

2 161

.674

2735

b. 044

-1.063

1.016

-1.019

2 360

.413

2 773

-.041

-1.040

1.060

-1.081

2 040

.680

2730

b. 130

-1. 185

1.035

-1.065

2096

.653

2 749

-. 161

-1.150

.903

-.999

2 061

.644

2 705

b.064

-1.181

1.071

-1. 127

1.966

.755

2 721

•

h 197
-.052

-1.210

.993

-1.013

2080

2 676

-1.042

1 023

— 1.094

1.830

.79*

2 618

b. 034

-1.302

1.097

- 1 . 168

2029

.707

2 736

-1.221

.894

-1.042

2 135

.461

2 506

-.347

.974

-1.013

1.684

1.0*5

2 760

+.623

-1.277

.633

-.654

2 413

.385

2 798

-.019

-1.010

1.027

-1.029

2 049

.061

2 710

b.osi

b. 121

-1.187

1.093

— 1 . 106

2 150

.(07

2 757

— 1 160

1.052

-1.048

2027

.745

2 772

b.2S9

-1. 136

. 846

-.847

1.990

.706

2 692

b.ow

-1.194

1 . 098

-1.096

2228

.525

2 753

-.031

-1.117

1.118

—1.086

2563

.303

2 865

b. 030

-1.050

.991

-1.020

1.905

.842

2 647

h 136
b- 31
b 373
b. 024
. 336

—.958

. 893

-.822

1.924

.821

2 745

-1.224

. 952

-.913

1.877

.873

2 750

-1.187

.948

-.814

2 139

.5*3

2 721

-1.144

1.064

-1.120

1.960

.812

2 762

— 1 . 2(0

.983

-.954

2119

. 678

2797

b.272

-1.027

.952

-.844

21, and 23, table 4) have a positive octahedral charge,
and the algebraic sum of these positive octahedral
charges and the corresponding negative tetrahedral
charges yields values for inherent layer charge con-
sistent with the corresponding values for K(Na,Ca).
Thus Holzner’s formulas also exhibit the 2 types of
adjustment for R + * cations that were found in the
formulas used in this study, 1 of which, adjustment
in accordance with equation A, is not explained by his
hypothesis, which is based entirely on accommodation
in accordance with equation B.

R+i.R+i relation in trioctahedral micas

In the accommodation of trivalent octahedral cations
according to equation A, (+2nR + *) = (— nR +, ) +
(— nSi* 4 ), the proxying of trivalent for bivalent octa-
hedral ions is 1 to 1. In accommodation according to
equation B, (+2nR +3 ) = (— 3nR +2 ) + (— nOct.Pos.), the
proxying of trivalent for bivalent octahedral cations is
2 to 3 or 0.67 to 1. As both methods are exhibited to
varying degrees in the natural trioctahedral micas
studied, it follows that the proxying of trivalent for
bivalent octahedral cations in these micas must vary
between 1:1 and 0.67:1, depending on the relative
degrees to which accommodation was made by one
way or the other. This is illustrated in figure 9, in
which the number of R + * cations displaced is plotted
against the number of proxying octahedral R +a and
R^ cations. With few exceptions all the points fall
along or between line A, which represents the proxying
ratio of equation A, R + *:R +, =1:1, and line B, which
represents the proxying ratio of equation B, R +, :R + *=
0.67:1. Most of the points representing formulas
having a trivalent octahedral cation content of less than
0.40 positions, as in most trioctahedral micas very high
in Mg, that is, phlogopites, lie on or close to line A,
whereas points representing formulas having a trivalent
octahedral ion content of more than 0.40 positions lie
closer to line B. These relations agree with the type of
adjustment found for different amounts of additional
trivalent octahedral positive charges in the average
formulas (table 2). In trioctahedral micas in which
the trivalent ion content is low, accommodation for
their extra charges is predominantly in accordance with
equation A, and the proxying ratio iB 1 to 1. With
increase in trivalent octahedral ion content an in-
creasingly greater degree of accommodation is made
according to equation B, and the proxying ratio
approaches more nearly 0.67 to 1.0. As the triocta-
hedral micas generally exliibit both types of accom-
modation for octahedral trivalent cations, an equation
representing the change in composition involved, as
compared with the ideal, must be a combination of
equations A and B. However, as the relative degree

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

Pkivki 9.— Relation bclwwn It* 1 cations displaced and proiyln* R” (ond R**)
oclab<xlral cations.

to which the two types are used differs with each
individual, the equation would, consequently, differ
with each individual. The difficulties are further com-
plicated by Ti which carries twice as many extra charges
as octahedral positions occupied.

The scarcity of formulas having an octahedral
R 43 (+R 44 ) occupancy of more than 0.90 positions
suggests that this R 43 (+R 44 ) occupancy (about one-
third of the occupied octahedral positions) is about the
upper limit of the R 43 by R +s (+ R 44 ) replacement in
the trioctahcdral micas. This is shown another way
in figure 10, in which histograms represent the type
and number of formulas hi each additional positive
octahedral charge group. Group H, in which the
number of additional octahedral positive charges is
between 0.71 and 0.80, includes the greatest number of
formulas (25). From this high the number of formulas
in each successive group drops to 1 G in group I and to
2 in group J. This sharp drop in the number of formu-
las in each succeeding group from the high in group H,
and the scarcity of formulas having an R 43 occupancy
greater than 1.00, supports the suggestion that an

537919—59 8

R 43 (+R 44 ) octahedral occupancy of one-third of the
octahedral positions is the essential limit of replace-
ment of octahedral R 43 (Mg) by R 43 (and R 4 ‘) in the
trioctahedral micas.

The small number of formulas having more than 1.00
positions occupied by R 43 and R 4 ' is also strong evi-
dence against the existence of a complete series be-
tween phlogopite and muscovite and supports Deer
(1937, p. 449) and Hutton (1947, p. 482) in their con-
clusions that it is not likely that the number of octa-
hedral positions occupied varies between 2 and 3, as
postulated by Pauling (1930, p. 128). Deer believed
that any value between 2.5 and 3.0 is possible, but
Hutton set the lower limit for octahedral occupancy at
not less than 2.75. In six formulas used in the present
study in which Ii 43 and R 44 occupied 1.00 ±0.10 octa-
hedral positions, total octahedral occupancy was be-
tween 2.45 and 2.75 positions, and averaged 2.60. In
the two formulas having the lowest octahedral occu-
pancy, 2.45 and 2.51 positions, accommodation for
trivalent octahedral cations is almost entirely in
accordance with equation B.

Mf-Fe+» RELATION IN TRIOCTAHEDRAL MICAS

In addition to replacement of Mg by R 43 cations in
the octahedral layer of trioctahedral micas, there is also
replacement of Mg by Fe 41 cations. With but very
few exceptions, all the formulas calculated from analyses
of trioctahedral micas contain both Fe 43 and R 43
cations in the octahedral group. The exceptional
analyses are of two kinds — almost pure phlogopites
that contain only a very small amount of Fe 43 cations
but no octahedral R 43 cations, or vice versa, and
biotites in which Fe 43 was not determined but was in-
cluded in total Fe as Fe*Oj in the analysis. Thus, co-
incident with replacement of Mg by R 43 cations, there
is also replacement of Mg by Fe 43 cations. A very
general relation between the amounts of Fe 43 and oc-
tahedral R 43 is suggested by the histograms in figure
10; (1) in formulas having very little octahedral R 43 ,
Mg is greatly predominant, (2) in formulas having
moderate amounts of octahedral R 43 , Mg is still dom-
inant but less so than in (1), and (3) in formulas hav-
ing more than 0.G0 octahedral positions occupied by
R 43 , Fe 43 is the dominant octahedral cation in most of
the formulas. However, the histograms also show the
presence of some Mg-dominant biotites in the higher
Ii 43 groups. This fact, and the great variability in the
Fe 43 -octahcdral R 43 ratio in the formulas indicate that
no real relation exists, and that the two scries, although
concurrent, are independent. Also, the amount of
octahedral R 43 present has no relation to the amount
of Fc 43 present, and vice versa. On the other hand,
the presence in all but a very few of the formulas of

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

both R +s and Fe +J in the octahedral group indicates
that neither type of replacement forms a separate series.
This statement includes Winchcll’s annitc, the Fc +1
analog of phlogopite, and the theoretical end member of
a Mg-Fe + * replacement series. Such a mica was not
found among the more than 200 analyses collected for
this study.

Substitution of Fe +J for Mg poses no problem of ad-
justment as docs the substitution of R +3 for Mg. Both
cations are bivalent, no excess nor deficiency of charge
is involved, and substitution is ion for ion with no other
change in the octahedral or tetrahedral layers.

On the evidence of the analyses and their derived
formulas, an octahedral occupancy of more than 2.20
positions by Fc + * is not to be expected. The highest
Fe + * in the formulas studied was 2.17, and only 4
formulas had an Fe +1 octahedral occupancy of more
than 2.00.

MAGNESIUM REPLACEMENT SYSTEM

It has been shown that the only trioctahedral micas
in which all, or almost all, the octahedral positions arc

occupied by one kind of cation are some phlogopites in
which more than 90 percent of the octahedral positions
arc occupied by Mg. The Fe + * analog of phlogopite,
Winchell’s annite, apparently does not exist in nature,
or is very rare. With pure phlogopite as the prototype,
all the other trioctahedral micas may be derived by the
replacement of Mg by, most commonly, Fe + * and R +s .
Thus, the trioctahedral micas may be considered as
members of a system in which two principal types of
replacement proceed concurrently but independently.
The relation between Mg, (Fe +J and Mn), and (Al,
Fe +S , and Ti) in this system is shown in figure 11, in
which, for each formula, the percent of occupied
octahedral positions occupied by Mg is plotted against
the percent of occupied octahedral positions occupied
by Fe +1 and R +s on a triangular diagram. The points
fall into 2 large groups and 1 small group. The first
large group, at the top of the triangle, is made up of
points representing trioctahedral micas in which Mg
occupies more than 70 percent of the occupied octahedral
positions; in the second large group are the points that
represent trioctahedral micas in which Mg occupies

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INTERPRETATION OF TRIOCTAHEDRAI, MICAS

between 63 and 20 percent of the occupied octahedral
positions; in the small group, at the bottom of the
triangle, are points representing trioctahedral micas in
which Mg occupies fewer than 10 percent of the occupied
octahedral positions.

Three-fourths of the analyses from which the for-
mulas represented by points in the first group were
derived were designated as analyses of phlogopite in
the literature. A few were termed “biotites”, with
biotite being used in a general sense, simply meaning a
trioctahedral mica. Consequently, the first group is
considered as being made up of pblogopiles and the first,
hiatus in the grouping of the points is considered as
differentiating phlogopites from Mg biotites.

The second group of points represent biotites. Points
representing Mg biotites occupy the upper half of this
area, and, about halfway down the area, mingle with
the points representing Fe + * biotites, which occupy the
lower half of the biotite area.

The third group of points represent Fe +i dominant
formulas having a very low Mg content, less than 0.15
octahedral positions, and high amounts of A1 and (or)
Fe 44 , that is, siderophyllitcs and lepidomelanes.

The trioctahedral micas may, therefore, be thought
of as members of a system characterized by concurrent
but independent replacement of Mg by Fc +1 and R +!
ions. At the beginning of the system, Mg occupies
more than 98 percent of the octahedral positions; at its

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

ond, Mg occupies fewer than 1 percent of the occupied
positions. Thus phlogopite, Mga.{ 0 (Sij.<»Al)Oio(OH)aK,
is the prototype of the trioctahedral system, from whicli
by displacement of Mg all other trioctahedral micas
may be considered to be derived.

It is obvious that the character and composition of
the members of a system like this cannot be adequately
expressed by the kind of formulas usually given for
these minerals. Such formulas suggest minerals of
definite composition, not members of a system that are
variable, within limits, in composition and that merge
into one another. For members of such a system the
formulas should indicate permissible limits of composi-
tion. The failure to define compositional limits has led
in the past to considerable confusion in differentiating
the various members of the system.

PHLOGOPITES

The name ‘‘phlogopite” refers to a trioctahedral
mica in which almost all the octahedral positions are
occupied by Mg. The formula usually given for
phlogopite, Mg 3 (Si,Al)Oio(OH)*K, specifies a complete
occupancy of the octahedral group by Mg. Naturally-
occurring phlogopites, however, contain other octa-
hedral cations, most commonly Al, Fe +3 , and Fe +2 , and
so do not conform perfectly to the ideal formula,
although some, like the one below (1, table 11), ap-
proach the ideal \ cry closely

+o.o« -i.ee

[ (Alo.oiT4.wF(*aoil'< 1 cfoiMg2,»i) (Si2.nAli.(«)Oi»(OH)i]~‘- (>l

2.90

Ko.rt.Nno.u.Bn/I^.w)^ 04

This formula has the highest Mg occupancy of any
of the formulas studied, Mg occupying 98 percent
of the octahedral positions. Even in this formula,
however, there are determinable amounts of Al, Ti,
Fe +3 , and Fe +i . Other formulas of phlogopites, ar-
ranged in order of decreasing Mg content, exliibit
increasingly greater occupancy of octahedral positions
by other cations, Fe +J , Fe +3 , and (or) Al. However,
all the formulas represented by points in the phlogopite
area, figure 11, have more than 70 percent of their
occupied octahedral positions occupied by Mg.

The average octahedral composition of plilogopitcs,
based on the 42 formulas at hand, are shown in table
5. Only 4 of these formulas bar! a Fe + * occupancy
of more than 0.45 octahedral positions; in 2 of these
Fe + * occupied 0.50 positions, in the other 2, Fc +3 oc-
cupied 0.54 positions. The number of octahedral
positions occupied by R +3 ions varies up to 0.54, with
Al occupying between 0.00 and 0.35 positions, Ti

Tabi.f. 5. — Range in octahedral composition of phlogopites ( in order
of decreasing Mg content in terms of octahedral positions)

Number

formulae

R** ettra
charge

Fe»i

Fe**

Octa-

hedral

positions

3.0O-2.7A

0. (0-0. 25

0.C*H) 15

0.00-0. 10

0.09-0. IS

1.00-295

2. 75-2. 50

.25- .35

. 10- . 21)

.05- .20

.00- .20

3. (0-2. M

2.50-2.25

. 20- . 45

.t<>- .25

. 00- . 30

.15- .t0

3.00-2.84

2. 25-2. 00

.25- .50

.00- .35

.05- .25

.30- .JO

3.00-2.85

Formula iruUcallng rang! in competition of pMogopllct
<+0.30 (-1.00M-1.30)

(It<o.5«I'f <o,soMgj .o>-j.m) (Sij.oo-j.ioAli ,(o-i . 10 )

3 00-2. Si

0 I< ,(OH),K(Na,Ca/2) 1 .»*o.i.

between 0.00 and 0.10 positions, and Fe +3 between
0.00 and 0.30. However, in 30 of the 43 phlogopite
formulas Al occupies 0.15 or fewer octahedral positions,
and in 7 of these there is not only no octahedral Al,
but also insufficient Al to complete the filling of the
tetrahedral group, necessitating allocation of some
Fe +S to this group. Although Fe +3 occupies up to
0.30 positions, most of the plilogopite formulas had
less than half that many positions occupied by Fe +3 .
Titanium is generally very low, occupying an average
of 0.10 positions.

From the ranges for Mg, Fe'*, and R +3 in these
formulas, general limits for these constituents in
plilogopitcs may bo formulated as shown at the bottom
of table 5. The low of 2.00 octahedral positions
occupied by Mg is equivalent to approximately 19
percent of MgO, and the high of 0.50 positions occupied
by Fe + * is equivalent to approximately 8.5 percent
of FeO.

A number of phlogopite analyses w r ere discarded
because the formulas derived from them were low in
interlayer ion content, that is, deficient in the amount
of K, or other large cations present, and (or) were
excessively high in octahedral occupancy. The im-
plication of these features is discussed earlier in this
paper.

EASTONITE

The name “eastonite” for pure dialuminum mag-
nesium mica, I^K-MgsAljSijOji, or (Al 0 ^Mg 2 . s )
(Si J . s Ali.»)Oio(OH) J K, in the notation used in this study,
was derived from Easton, Pa., where, quoting Winchell
(1925, p. 322, footnote 30) “Eyerman found a sample
which approaches this composition very closely'.”
Eyerman (1904, p. 46) published three analyses of
biotite from Easton. One of these, analysis B, has
only' 6.30 percent K.O, which is very low for a potassium
mica. In the formulas derived from his analyses A
and C, 16 and 15, table 11,

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

+0.14 -1.16

KAl4.»Fc^Mg,. < ,) (Si, J4 Al,.„)O l .(OH) i l-^

2.87

( K(ij4 , Na< .m, i

and

+0.30 -1.28

l(Alp , t Fp^M^g».«) (Si» .^Al,.M)Q|«(OH)a]-*- , *(Koj»,Ca/2a.B,)o*M lw ,

2.83

Al occupies only 0.24 and 0.15 octahedral positions,
respectively, not 0.50 as specified in Winchell’s formula.
These formulas can be said to approach the composition
specified by Winchell’s eastonite formula only if Al is
interpreted broadly as meaning R +3 ions and to include
Fe +3 . Furthermore, it is very doubtful whether the
values given for FejO s represent the actual Fe +3 content
of the samples. No FeO is reported, and it is very
probable that FeO was not determined and that the
value given for Fe 2 Oj represents the total iron content
of the sample, not Fe +3 only. In most samples of
similar Mg and total iron content, in which both Fej0 3
and FeO were determined, FeO makes up one-half or
more of the total iron content. It is very likely, there-
fore, that the FcjO, reported in these analyses includes
FeO and that the actual trivalent ion content of these
biotites is considerably less than shown in the formulas.

Aside from the Al and the total trivalent ion content,
there are other points of disagreement between these
formulas and Winchell’s eastonite formula. In the
eastonite formula it is presumed that all the octahedral
positions are occupied, and, because tetrahedral Al,
and consequently, tetrahedral charge, is 1.5, that all
the extra charges (+0.50) carried by octahedral Al
induce a positive charge on the octahedral layer. In
the Easton formulas only 2.87 and 2.93 octahedral posi-
tions, respectively, are occupied, and only part of the
additional charges carried by trivalent ions form a
positive charge on the octahedral group, the rest being
neutralized by negative charges associated with unoc-
cupied positions. Consequently, the positive octa-
hedral charge, the negative tetrahedral charge, and
octahedral occupancy of the Easton formulas arc all
less than in the eastonite formula. X-ray stud} - of the
Easton, Pa., samples show them to be mixtures of
serpentine and phlogopite. (Hatton S. Yoder, oral
communication, 1957.)

Because in trioctahedral micas the extra charges
carried by trivalent octahedral cations are accommo-
dated in two different wavs, in accordance with equation
A or equation B, because decrease in Mg content, is
accompanied by increaso in Fe +2 and R +s , and because
increase in R +3 is made up of increase in Fe +3 as well as
increase in octahedral Al, none of the Mg dominant
formulas studied closely approach Winchell’s eastonite

527910 — 60 1

formula, in which accommodation for extra trivalent
charges is assumed to be made only in accordance with
equation A, and in which replacement of Mg is by Al
only. All the formulas with a Mg content comparable
to that in the eastonite formula contain Fe fS and Fe +S
and have some unoccupied octahedral positions.

Among the analyses of trioctahedral micas collected
for this study, only one had been called that of an
eastonite (Simpson, 1932, p. (53), (D27, table 12).
This analysis yielded the following formula,

+0.42 -1.28

I ( AI».»Tio.(af e 0 ‘ 24 Fc(7 mMpi.wM irf ) (Sij ;i Ali.»)0,o(OH),l' 0 .”

2.87

(Ko.(J,Nll« v;)oM ,a

In this formula Mg occupies only three-fifths and Al
occupies only two-fifths of the number of octahedral
positions designated in the eastonite formula, and the
octahedral and tetrahedral charges are both consider-
ably lower than in the eastonite formula. Only if Mg
and Al in the eastonite formula are interpreted broadly
as representing R +2 and R +J ions gonerallj 7 , does the
formula for Simpson’s eastonite,

+0.42 -1.29

[(Al, Ti, Fe*»V, t (rc+ Mg, Al I M )0,o(OH) > ]- < » 7

2.67

(K, Na) 0 + »° u w

approach Winchell’s formula for eastonite. However,
Winchell’s formula represents the hypothetical dialu-
minum magnesium mica which was used by him as
one of the components of biotitc and as an analog of
sidcrophyllite. A broader interpretation, as aliovc,
would tend to engender confusion with biotites proper.

In view of the confusion a broader interpretation
would tend to engender, the apparent lack of natural
representatives and the fact that the name had been
previously given by Hamilton (1899, p.19) to a vermic-
ulite occurring in the same locality as an alteration
product of biotitc, it is recommended that the name
"eastonite” be discarded as referring to a natural
trioctahedral mica and returned only as a hypothetical
end-member.

BIOTITES

The term "biotite,” although also used as a group
name for the trioctahedral micas, is here specifically
applied to trioctahedral micas that contain significant
amounts of both Mg and Fe +J . Biotites in which Mg
is the dominant octahedral cation arc termed Mg
biotites; those in which Fe +2 is the dominant octahedral
cation are termed Fe +2 biotites. Occurring midway in
the Mg Fe +2 -R +3 system (fig. 11) between a Mg octa-
hedral percentage of 50 and 20, the biotites occupy the

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greatest area and constitute the greatest number of
samples. Magnesium biotites dominate the upper
part, of the biotite area, with points representing
formulas having the highest Mg content occupying
the uppermost part of the area. With decreasing Mg
content and increasing Fe +1 content Mg is gradually
superseded bj r Fe +J as the dominant octahedral cation,
and Fe + * biotites dominate the lower part of the bio-
tite area. In the transition zone, points representing
Mg biotites, Fe +l biotites, and biotites having about
equivalent amounts of Mg and Fe +l intermingle.

The highest Mg content in any of the biotite formulas
studied is 1.77 octahedral positions, the lowest is 0.48
octahedral positions. The highest Fe +J content in any
biotite formula is 1.78 octahedral positions; the lowest
is 0.47. Thus Mg and Fc +l in these biotite formulas
have the same range, 1 .75 to 0.50 octahedral positions
(in rounded figures), but they are present in a reciprocal
relation. This relation is illustrated in the following
formulas, 36 and 116, table 11,

+0.05 -1.13

{(Alo.iiTi u .o«f eiMsFe^iMKi .r> (Sij.cAli.ij)0|o(OH),] -lw

3.78

(K«.Ti,Nao.ij,Ca/2o.]j)^(iV

+ 0.38 - 1.25

[(AU.«Tt,. w FequFei 4 r> <Sij.,jAI, .uXWOH), )-<>•»*

2.83

which belong, respectively, very near the high Mg-low
Fe +I and the low Mg-high Fe* a ends of the Mg-Fe + *
range in biotites. In other biotite formulas, the
Mg- Fe +I relation varies between these extremes.
However, because R + * ions are present in different
amounts, the relation between Mg and Fe + * is quite
variable. Formulas with similar Mg contents may
have quite different Fe +S contents and formulas with
quite different Mg contents may have the same Fe + *
contents. Similarly, the relation between Mg and
R +5 content is quite variable, as is also the relation
between Mg and any of the ions making up R+*.
The relation between Mg and (Fe*4-R +1 ) is however,
quite regular.

Fe +a generally occupies fewer than 0.35 octahedral
positions in the biotite formulas. Only C formulas
had a greater Fe +I content, and of these 6 only 1 had
a Fe +3 content greater than 0.45. There is no signifi
cant difference in the Fe + * content of Mg dominant
and Fe +:( dominant biotites. Indeed, the average
Fe +3 content of these two types of biotites is essentially
the same, 0.23 octahedral positions in Mg biotites, 0.25
octahedral positions in Fe +l biotites.

With respect to A1 content the biotite formulas fall
into two groups; in about one-half the formulas there

is little or no octahedral A1 (fewer than 0.10 octahedral
positions), in the other half, A1 occupies between 0.20
and 0.55 octahedral positions. In about one-third of
the low A1 group, A1 is so deficient that there is not only
no octahedral Al, but there is not even sufficient A1
present to complete the filling of the tetrahedral group ;
this requires the allocation of some Fe + * to this group
to complete it. Lack of sufficient Al to fill the tetra-
hedral group may be due simply to low Al content, or
it may be due to low Si content, which would require
proportionately more Al to complete the tetrahedral
group. A comparison of the amounts of Si0 2 and A1 2 Oj
reported in the analyses from which the formulas were
derived shows, however, that low A1 3 0 3 content, rather
than low Si0 2 content, is tho reason for the insufficiency
of Al in formulas containing little or no octahedral Al.
The SiO» content in analyses for the 2 groups is about
the same, varying between 32 and 38 percent in analyses
for both groups, with an average SiO» content of 35.5
percent for the low Al group, and an average of 34.8
percent for the higher Al group. The range in Al,O s
content in analyses of the low Al group, 11.0 to 16.3
percent, is, however, considerably lower than the range
in AljOj content of the higher Al group, 15.7 and 21.3
percent, and the average A1 2 0 3 content in analyses for
the low Al group is almost 4 percent lower than the
average A1 2 0 3 content in analyses for the higher Al
group, 14.6 percent as compared with 18.4 percent.

The compositional characteristics of each of the
groups for different ranges of Mg content are sum-
marized in table 6, and the average octahedral compo-
sition of each group for the same ranges of Mg content
are given in table 7. For comparable Mg contents the
low octahedral Al biotites are, in general, lower in R +s
but higher in Ti and Fe + * content than the higher

T able 6 . — Range in octahedral composition of biotites

|ln order of decreasing Mg content In terms of octahedral poaltSons occupied)

1.75-1. 50

1.50-1.25

1.25-1.00

1.00-0.73

0.73-0.50

AK0.15

Numbw of formulas.. .

R*»

Fe>*

Fe«

<F««+R«)

0.330.70
.00- .03
. 30- .23
. 10- . 43
.00- .90
1.05-1. 30

0. 60-0. 75
.00- .15
.10-20
.20- .35
.80- .95
1.25-1.80

0. 50-0.80
.CO- .15
.20- .30
. 10- . 45
.VO-1 33
1.45-1.83

0. 43-0. 80
.00- .15
.03- .80
.10- .35
1.23-1.55
1.73-2.06

0. 53-0.85
.00- .15
.10- .30
. 03- . 45
1.45-1.75
2.05-2.20

Al>0.15

Number of formulas ..

F*«

F««

(Fo«+R*>)

0. 45-0. 70
.20- .55
.00- .15
.00- .25
. 30- . 95

1. QO-1.35

0.00-4). 80
.30- .40
.10- .20
.10- .25
.65- .95
1.30-1.55

0.60-0.90
.30- .80
.00- .15
.00- .40
.70-1.25
1.50-1.80

0.70-1.00
.20- .40
.10- .30
.03- .35
1.00-1.35
1.70-2.00

0. 55-0 90
.23- .50
.03- .20
.03- .30
1.13-1.70
1.90-2 2)

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INTERPRETATION OP TBIOCTAHEDRAL MICAS

Table 7. — Average octahedral composition of biotites in order of decreasing Mg content
(Tbe flsuro* prooodtn* the pareatbeara enclosing the octabodral-group notation rotor to the extra R« charge of tbe octahedral group* they prooedel

At <0.18

A) >0.18

1. 75-1. 50

+0.28

o.»( AU.wTia.io Fe#li*a F Colw Mg, .to)

+0.28

o.u(Alo.»Ti«.wFecf*jFectroMgi.»i)

2.85

2-85

1. 50-1. 25

+0.25

o.«(AIo.o*Tio.i»Fco[5)FeolS>Mgi .*o)

+0.28

».:» (Ah_j®Tio.uFe£t 3 j Fe^Jj Mgi .*>)

2 k

2.74

1. 25-1. 00

+0.30

».m( Alo.wTiojjFeo.ijFe^Jj Mgi . 10 )

+0.30

o.»( AIojiTU.isFc^jjF e^M Mgt . 10 )

2.80

2.75

1. 00-0. 75

+0.28

o.uCAlo.wTtj.uFcoiFe^iMgo,)

+0.25

«.u( Alo j©T . joFc^ fa F ej^o M gn . w)

2S0

2.70

0. 76-0. 50

+0.28

t .7» ( Al« .oaTio joFc£J> Fe Mge.»)

2.78

+0.28

» .»i ( Alo ,«Tio . ioFe^j S Fe i + *j Mg« ,(o)
2.70

octahedral A1 biotites, although formulas with low
octahedral A1 are found throughout the entire R + *
range. Fe +1 is consistently higher, for comparable Mg
contents, in low A1 biotites than in higher A1 biotites.
Because of this difference in Fe + * content with the
same Mg content, the average formula for low A1
biotites in the Mg range 1.25-1.00 has Fe^ 2 as the
dominant octahedral cation, whereas the average for-
mula for the higher A1 biotites has Mg as the dominant
octahedral cation. In an average of all formulas in
this Mg range Mg and Fe +S are present in approximately
equivalent amounts,

+0.30 -1.30

[ (Ala.ioTiaitFe^oFe^Mgi.i*) (Sij.roAli ,»)Oio(OH)

2.30

K(Na, Cu/2), + i“ 10

Thus the Mg range of 1.25 to 1.00 octahedral positions
is the transition zone between Mg and Fe +l dominant
biotites. All biotites having more than 1.25 octahedral
positions occupied by Mg are Mg dominant; all biotites
having fewer than 1.00 positions occupied by Mg are
Fe +2 dominant. When the Mg content is between 1.25
and 1 .00 octahedral positions, Mg is dominant in some
biotites, Fe +! is dominant in others, and Mg and Fe +i
are present in approximately equivalent amounts in
still others.

On the basis of the ranges in content of Mg, Fe +2 , and
R +s shown in table 6, the ranges in content of these

constituents to be expected in biotites may be for-
mulated as

<+0.» (-I.OO)-(-l.SO)

( - i.oo l - i.7jMKi.:jj).»)(Sii . ».i .*>Alt.o).i.to)Oio(OH)j
3.99-2.83

K(Na, Ca/2)i.M±,.tt.

ANNITE

Originally the name “annite” was applied by Dana
(1868, p. 308) to a high Fe +J biotite that occurs at Cape
Ann, Mass., which was analyzed and described by Cooke
(1867, p. 222). This material contained 12.07 percent
FejOj. Subsequently Winchell (1925, p. 323) applied
the name to a hypothetical Fc +1 analog of phlogopite,
Fei'*(SijAl)Oio(OH) a K, which was used by him as 1 of
the 4 components of biotite. Thus the name which
Dana gave to a high trivalent iron mica was applied by
Winchell to a hypothetical bivalent iron mica which was
presumed to contain no trivalent iron.

One of the most significant features brought out by
this study is the complete absence of Fe +2 dominant
micas analogous to phlogopite. Only two formulas
have as many as 2.00 octahedral positions occupied by
Fe +2 , the lower limit for Mg in phlogopite, and in these,
although Mg is very low, R + * ions occupy about 0.50
octahedral positions.

Considering that the name “annite” had been used
previously by Dana for a high Fe + * biotite and the name
and formula was used by Winchell for a hypothetical

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

ferrous trioctahedral mica, which does not, on the evi-
dence of the formulas gathered, occur in nature, it is
recommended that annite be discarded as referring to a
natural trioctahedral mica, and retained only as a
hypothetical end member.

SIDEROPHYLLITES AND LEPIDOMELANES

A group of Fe +J dominant trioctahedral mica formulas
in which Mg occupies less than 0.15 octahedral positions
represents the end of the Mg replacement system.
Points representing these formulas fall close to the base
of the triangular diagram shown in figure 1 1 , and are
separated from the biotite area by narrow, very sparsely
populated area. Some of these formulas are char-
acterized by high A1 content ; others, by high Fe +S con-
tent; and still others, by significant amounts of both
A1 and Fe +a .

Siderophyllite, according to Winchell and Wincliell
(1951, p. 373) has the formula, H^KjFeiAbSijOj*, or, in
the notation herein used, and assuming Fe to represent
Fe +1

(AbjFei*) (Sii.nAlt . w )O le (OH),K,

The full octahedral occupancy and the composition of
the tetrahedral in this formula indicate, that all the
accommodation for extra positive charges (+0.50)
carried by octahedral A1 is assumed to have been made
in accordance with equation A. Nockolds and Richey
(1939, p. 38) suggested the formula, 1 1 ,K 2 F e 3 AJ«8i*0 2< ,
or (Al,.ooFei + »)(Sij,ooAli.oo)Oio(OH)jK, for siderophyllite,
as this formula was closer to the composition of a
specimen studied by them (129; table 8). In this
formula all the additional positive charges carried by
octahedral aluminum (+1.00) are accommodated in
accordance with equation B. The octahedral layer is
neutral, and the tetrahedral layers have the same
charge as in the classic formulas for phlogopite and
muscovite. These two formulas, therefore, represent
the two extremes in the accommodation of extra posi-
tive octahedral charges by the biotite structure. Octa-
hedral Al in this formula occupies twice us many posi-

tions as in the Winchell formula and Fe +l occupies only
three-fifths as many positions.

In the formulas shown in table 8, octahedral Al
varies between 0.47 and 0.99 positions. These rela-
tions suggest an isomorplious series in which Fe +J is
replaced by Al. Hypothetically, the beginning of the
series would be a mineral similar to Winchell’s annite,
which would yield on increasing replacement of Fc + * by
Al, minerals whose compositions, except for lack of
Li, approximate those of the siderophyllites shown in
table 8:

0.00 -| .oo

|Feti(Sij.o*Ali.oo)Oio(OH)i) -1 - 00 Kj^j 00 Not represented.

0.00 -1X0

l(AU.„F,' 1 t , i, 8 )(Si l «Al, *)0,o(OH) 1 )-> M Kfik 00 Approximates

0.00 - 1.00

[(Ajij»Fe^M) (8ij .ooAli.o»)Oio(OH),) -1 ® KtJo 0 Approximates
' ^ 129, table 8.

The first half of the series, up to an Al content of 0.50
octahedral positions, is not represented among the for-
mulas studied. The second half is represented by for
muias in table 8. Variations in octahedral occupancy,
octahedral charges atid tetrahedral charge are due to
the varying degrees to which the structure has accom-
modated the extra positive charges carried by Al in
accordance with equation A or equation B. In the for-
mula for 132, table 8, 0.33 of the extra 0.47 charges
carried by Al are balanced by the deficiency in the
number of charges carried by Li, as one Li and one
Al together carry the same number of charges as two
bivalent cations. The 0.16 negative charges associated
with 0.08 unoccupied octahedral positions arc more
than sufficient to neutralize the rest of the additional
positive charges, and the octahedral layer has a slight
negative charge. In the formula for 135, table 8,
part of the additional positive octahedral charges are
neutralized bv negative charges associated with unoc-

Table 8. — Formulas of representative siderophyUiies

Number in table 11 Formula

- 0.02 — 1.00

132 — .......... [(Alo.trFivffli Mgo.qaMiio f ^L4^i) (Sij.i*A]|jw)Oia(OH)2]“ ,w (Ko.taNao.fciItl>o.w)u>3 OS

2.92

+0.35 -1.35

135 [(Alo.nFei^Fe^Mgo.o,Mii^OTr+.,>) (Si t . w AI, j t )Oi.(OH)tl- | - M (Ko.wNa(,.wCa/2o.o,)^ w

2.89

- 0.00 - 1.03

129 [(At,„TUo.Fe 0 V a lvaMto. w Mri 0 ^) (Si,. w AI,. c )0,o(OH)d-‘-” (K„.„C nil,.,,)?.# 0

2.44

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

cupied octahedral positions. In 129 all the extra posi-
tive R +3 charges are neutralized by negative charges
associated with unoccupied octahedral positions, as in
Nockolds and Richey’s formula for siderophyllitc.
Because of these various degrees to which the extra
positive charges carried by R M ions have been accom-
modated in accordance with equations A and B in
these siderophyllite formulas, the formulas for the
siderophyllitc series are written to represent similar
mixed accommodation of extra positive charges.

“Lepidomelane” is a term that has not been de-
finitely defined and that has different meanings for
different mineralogists. Dana (1892, p. 634) defines
lepidomelane as a variety of biotite characterized by
a large amount of ferric iron. Winchcll and Winchell
(1951, p. 376) states that "lepidomelane is any kind of
biotite rich in iron.” The state of valence of the iron
is, apparently, unimportant, as this definition would
include his annite. Kunitz (1924, p. 388) suggests
that all the iron was originally in the ferrous state,
and gives a formula in which all the iron is present in
the ferrous state, KH 2 AlFeV(SiO«). However, Halli-
mond (192G, p. 30) considers that there is no reason
“* * * to believe t hat the natural melts are so deficient
in oxygen as this assumption would imply, and it is
much more probable that the average fresh biotite is
substantially in the condition in which it crystallized.”
The formula given by Hey (1955, p. 193), 2[K 2
(Fe + *Fe + *Mg)«_».(Si,Al,Fe + *) l Ojo(OH) 4 ], which includes
both trivalent and bivalent iron, is qualified by the
remark “* * * with high Fc +S and low Mg (usually
Fe +J >Mg).” Hey includes Fe +S in the tetrahedral
group, as does also Grigoriev (1935, p. 79) in his formula
for fluor (or hydroxyl) lepidomelane FK(MgFe +3 )j
[(Al,Fe +3 )Sij]Oio, although Grigoriev includes only Fe +3
in the octahedral group. These examples illustrate
the lack of agreement among mineralogists as to the
meaning of the term “lepidomelane.”

Among the Fe +3 dominant formulas studied was a
group characterized by very low Mg content and
analogous to the siderophyllite formulas but containing
Fe +S in place of Al. These formulas, of which typical
examples are presented in table 9, bear the same relation
to each other as do the siderophyllite formulas; that is,
they represent part of an isomorphous series in which
there is proxying of Fe +I by Fe +3 , and their composition
can be expressed by the same general formulas as
given for the siderophyllite half scries, by substituting
Fe +3 for Al.

0 0° - 1.00

1 t’ ejui (Sij .oo Al, j») 0io(0 H ) j) -1 •” K, + i°° Not represented.

o.oo -i.oo

KFco + j>Fc a ^ )(Si 3 . 00 AI,. w )0„(OH) > i ■ « K.+i, 00 Approximates
^ 124, table 9.

0.00 -1.00

( (Feij»Fe^a>) (S13.00 All ‘>?)Oio(0 H ) ,]‘ ira K i + oo°° Approximates

123, table 9.

As in the siderophyllite series, only the latter half of
the series is represented.

It is suggested here that the term “lepidomelane” be
applied to minerals similar in composition to the for-
mulas above and to those in table 9 — minerals char-
acterized by high Fe +3 and Fe +3 and by very low
octahedral Al and Mg content, and analogous to sidero-
phyllite (as herein defined) but containing Fe +3 in place
of Al.

Another group of formulas characterized by high
Fe +3 and very low Mg content contain significant
amounts of both octahedral Al and Fc +3 (table 10).
These formulas are intermediate in composition be-

Tablb 9 . — Formulas of representative lepidomelanes

A'ur*Vr

(toM< //) Formula

+0.17 - 1 .23

126 | (Al 0 . t oTi t ,.„Fe 0 + i i Fe?:, 2 1 Ms > . w M^) (Si:. ; ,AI,. M Fe^ii)0,o(OH),l-'-*(K,. n Na c ., ( Ca/2,.^),^ 11

2.73

+0.22 -1.11

125 [ (Al 0 ,,Ti CJ ,Fo 0 \* 7 Fca\lg». t ,Mi^) (Si, J ,AI,.,,)0, t (OII),l-«t«(K«. 7 ,Na,.,.)o + , < li w

9.08

+0.39 -1.49

124 | (Al 0 . w Ti 0 , w Feo + /,Fe^? 7 M^.„Mn 0 ^) (Si 7 ^AI,. t ,)0,,(OH),l-»^(K.. t ,Nao,,) 1 4 ( y a

2.89

+0.39 -1.86

123 [ (Ala.nTia wFcq^Fckt? Mg«.nMno[OTl'b.n) (8l 7 .M Ali.M)Oio(OH),)~' 0 ' ,, (Ko.^Ca/2 < . w ) 0 < °7 <>i

3.76

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Table 10 . — Formula i 0/ mica* irttermediale in composition between eider ophylhtis and lepidomelanes

Number

(IsMm II as A II) Formula

+0.38 -1.31

130 — .... — [ (Al»»tFBoj47Fe*TOMft).o<Mn^»Lit.M) (Sii.)iAli.»i)O l (i(OH)i|-*- t> (Ko.nNao.MCa/2<i.t4)fr»i* t

2.84

127

+0.24 -1 .32

[(AL.nT4.oiFPo.jjFei + j2Mgo.«»Mii<> i OTL'io.ijKSij.MAli.ij)Oio(OH)jl“ 1 ■ n (Ko.!«N"ao.,uCa/2o,M')(t 1 ii W

2.81

D63

+0.01 -1.02

I(Al«.«Fe^«*Fe, + (S(MKo.»7Mii^(Hl<io.iii)(Sij.»jAli.OT)Oio(OH)jl" ,<I K 1 + o I i ,>1

2.41

tween those given in tables 8 and 9. Other formulas,
which could not be used because of their high alkali
content (see discussion, p. 16), contain varying
proportions of A1 and Fe +3 and suggest the existence

of an isomorphous series between sidcrophyllite and
lcpidomelanc as they are herein defined. The inter-
relations possible between siderophyllites and lepid-
omelanes are expressed in the following diagram.

(Aln.soFe^ ’jLiju) (Sij.i»Ali.u)Oio(OH)iK|.o

(Ali.ooFc^iLU.ij) (Sit.uAli.u)Oie(OH)]Ki.g < »

(Fe 0 + i,F^Li,..»)(8i.. M Al 1 . 15 )O l ,(OH),K 1 .,

(Fcj&Fe&Li*.,,) (Sij.uAl, .„) 0,»(0H) ,K,

Micas intermediate in composition between sidero-
phyllites and lepidomelanes can be referred to as ferrian
siderophyllites or aluminian lepidomelanes, depending
on whether aluminum or trivalent iron is the dominant
trivalcnt octahedral cation. By this terminology all
the formulas in table 10 would be called aluminian
lepidomelanes, as the number of octahedral positions
occupied by trivalent iron is greater than the number
of positions occupied by aluminum in all of them.

Only one formula in tables 8, 9, and 10 contains
tetrahedral trivalent iron, as specified in Hey’s and
Grigoriev’s formulas for lepidomelane. The presence
or absence of tetrahedral Fc +3 in a formula is indicative,
not of high Fe +3 , but of insufficient Si or A1 to fill the
tetrahedral group, as Fe +I is assigned to the tetrahedral
group only when there is insufficient Si and A1 to fill
that group. Some of the phlogopite, formulas calculated
for this study contain tetrahedral Fe +3 because the A1
content is very low and is not sufficient to complete
the filling of the tetrahedral group, although the Fc +3
content is also very low. Thus tetrahedral Fe +3 is not
a necessary characteristic of high Fc +3 biotites.

CHEMICAL COMPOSITION AND GEOLOGIC
OCCURRENCE

The trioctahedral micas form under a great variety of
conditions and occur in many kinds of rocks — in igneous
rocks, both intrusive and extrusive, ranging in composi-

tion from felsic to ultramafic; in metamorphie rocks,
such as gneiss, schist, marble, and “serpentine” (ser-
pentinite); in pegmatites; and in hydrothermal veins.
As the chemical composition of trioctahedral micas
depends not only on kinds and relative proportions of
elements present at the time of their formation but
also on other environmental factors, micas from different
kinds of rocks would be expected to differ in compo-
sition.

Information on geologic occurrence was available
for about, two-thirds of the analyses used in this study.
Most of the analyses for which such information was
available were those of biotites, siderophyllites, and
lepidomelanes. Information on the phlogopites was
sparse, and that available indicated quite diverse occur-
rences. The kinds of rocks from which there were
enough micas to furnish an adequate conception of the
composition of the micas in them were divided into the
following groups: Granite, monzonite and quartz mon-
zonitc granodiorite, diorite and quartz dioritejnephe-
line syenite, gneiss and schist, and pegmatite. Micas
that, formed under apparently atypical conditions such
as a biotitc from a large zenolith (plagioclase) in biotitc
granite, or a biotitc from a dark veinlct in granite, arc
not included in this discussion.

The relation between the chemical composition of
the micas and their geologic occurrence is shown in
figure 12. In this figure the Mg-(F e +l ,Mn)-(Al,Fe +3 ,

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

Fioi'RK 12. - Relation In-tween chemical compoottioo and goolojlc occurrence ol trlodahedrn) mhxu.

Ti M ) relation in the octahedral group of each mica is
plotted on a triangular diagram, as in figure 11, and
the area occupied by points representing micas from a
given kind of rock is enclosed. The occupied areas
indicate that the micas from the first six groups of
rocks are all biotites; those from the seventh group,
with a few exceptions, are siderophyllites or lepidome-
lanes.

Hiotiles jrom granite . — Biotites from granite comprise
the largest group (23). Points representing these
biotites occupy an area (gr) in figure 12 which embraces
almost the entire biotite area as shown in figure 11.
Thus biotites from granite vary widely in character,
from those in which Mg is greatly predominant, as in

these formulas calculated from analyses 41 and 42,
table 11.

40.2# -1,84

l(AU.nTVnFeo.iMFe<^Mgi.«iMntf,?() (8ii.wAli.tt)0|o(OH)i)~ > - w

3.84

(K« J ,,Na,.u,Ca /W& 0 *
+0.31 -1.28

[(Ah niTU. w Fp^ioKp£joMKi.qiMnaoi) (Si>.nAli ,a)Oi#(OH)j) _,-W

3.84

(K«.ai , Naa.it, Ca/2| ai) tif*

to those in which Fe + * is similarly dominant, as in these
formulas calculated from analyses 116 and 120, table 11.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

l(Alo.»Tio.*Fe I f? 3 Kei]j»M|&i.!4Mn,J ( jj} (Si>.TiAl|jj)Oio(OH)>l -0 - H
2.82

(K« Ml ^>8o .01 , Cu/2o m)o. s»° S
+0.37 -1.34

I(AlojtTio.uFeo^| 3 4Fe l ]ftaMgi).»Mii<^? l ) (Sia.MAl l ji)Oia(OH):]~ 0>7
3.86

(Kc.74,NBo.or,C!»/2*j:)aM tl5

In terms of percent composition, biotitcs from granite
.varied between 14.92 and 4.70 in MgO and between
12.69 and 26.80 in FeO.

In about one-half the biotitcs from granite, octa-
hedral aluminum occupies fewer than 0.15 positions, as
in 42 and 116, table 11 above. In some of these there
is no octahedral aluminum, the aluminum present being
insufficient to complete the filling of the tetrahedral
group, and it was necessary to allocate some Fe +S to
that group. On the other hand, in other biotitcs from
granite, octahedral aluminum is quite high, occupying
0.50 or more positions, as in this formula calculated
from analysis 110, table 11,

+0.36 -137

(Al^.iiTio.inFt'o jaFi’, 43 ;, Mg^u M (Si».«*AI| ji)t)io(OH),]- 101

3.77

(Ko.(«,Nao.«,Ca/2oj))o.i 01

In these biotites from granite, A1 2 0 3 varies between
13.64 and 20.55 percent.

FejOj content is also quite variable in these biotites —
between 0.35 and 8.0 percent. These amounts of
Fe 2 0 3 are equivalent to 0.02 and 0.44 octahedral
positions, respectively, occupied by Fe + *. In the
biotite in which Fe +S occupies 0.44 octahedral positions,
as well as in one other in which Fe +3 is fairly high and
octahedral A1 is fairly low, Fe +S is the dominant tri-
valent octahedral cation. However, in most of the
biotites from granite in which there is little or no octa-
hedral aluminum, there is less Fe + * than there is in
those that have considerable octahedral aluminum.
There is no apparent relation between FeO and Fe/) 3 ,
individuals of moderate FeO content may contain more
F e 2 0 3 than others with twice as much FeO and vice
versa.

The TiO s content of the granite biotites is quite
uniform, varying between only 2.0 and 3.75 percent in
18 of the 22 analyses of biotites from granite.

In their accommodation of the additional charges
carried by trivalent or quadrivalent octahedral cations
the granite biotites apparently do not greatly tend to
favor one method over the other, but exhibit a fairly
equal degree of adjustment by both methods. Thus
they are characterized by a moderate octahedral posi-
tive charge, +0.20 to +0.35, with an equivalent

excess over 1 .00 in tetrahedral negative charge, and by
a moderate decrease (below 3.00) in octahedral occu-
pancy, the number of octahedral positions occupied
being generally between 2.85 and 2.70.

In summary, therefore, biotites from granite differ
greatly in character and composition, varying from
those in which Mg is the considerably predominant
octahedral cation, through those in which Mg and
Fe +J are approximately equal, to those in which Fe +J is
considerably predominant. In any of these, octahedral
A1 may be very low or absent, moderate or high, and
Fc +3 may be insignificant or an important constituent.
Fuller data on the kinds of granite from which these
biotites are derived might permit correlation between
a particular type of granite and a particular type of
biotite, but with the data at hand this is not possible.

Biotites from monzonite and quartz mon zonite .— Only
three of the biotites for which information as to geo-
logic occurrence is available were from monzonite or
quartz monzonite. Of these, the 2 from quartz mon-
zonite (1 from Colorado and 1 from California) were
very similar in composition, as shown by these formulas
calculated from their analyses (48 and 50, respectively,
table 11).

+031 -130

[(Aio.47Tio. t Fe 0 > 3 3 7 Fe 0 ^Nlg,.,,>ti^ )(Si,,, 1 ,Al, J8 )O l o(OH),l- 0 - w

3.86

(Ko.;»N»«.0j|Ca/$>.4«)^8o >9
+031 -138

[( Alo.oi’I'io.isF<\j + ji Ffo’i Mgi ,i;.M iio'm) (Si» .7* AI| Ok>(OH) *1 — °-* t

2.83

(Ko.isjNae.iji.Ca/^ji)^® 7

Both are Mg dominant biotites with very low octa-
hedral A1 and moderate Fe +3 content. Both have a
moderate octahedral positive charge, with an equiva-
lent increase in the negative tetrahedral charge; and in
both the deficiency in octahedral occupancy is moderate,
which indicates about equal adjustments by methods
A and B for the additional positive charges carried by
trivalent and quadrivalent octahedral cations. In the
third member of the group, a mica from monzonite in
Thuringia, Mg and Fe +2 occupy 1.01 and 1.02 octa-
hedral positions, respectively. This biotite is also
somewhat higher in Fe +3 content than the other two
from quartz monzonite, but it is similar to them in
octahedral and tetrahedral A1 content and in TiOj and
M 11 O content. In this biotite one-third of the adjust-
ment for additional positive octahedral cations is by
method A and two-thirds is by method B.

The points representing these three biotites fall on
the left boundary of the area occupied by biotites from
granodiorite (gd), figure 12.

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INTERPRETATION OP TRIOCTAHEDRAL MICAS

Biotites from granodiorite. — The eight biotites from
granodiorite occupy a large area (gd), in the upper
part of the granite area (fig. 12). It also overlaps the
line (Mg:Fe +a =l :1) between the Mg and Fe +a domi-
nant biotites; thus both types of biotites are obtained
from granodiorite. In these biotites, Mg and Fe +a
together generally occupy from approximately 2.30 to
2.45 octahedral positions, but the relative proportions
of the two cations present varies greatly, as illustrated
in the following formulas calculated from analyses 44,
67, and 111, table 11,

+ 0.33 — 1.26

[(Al^Ti, j.F^Fep^, Mg, (81,.,, Al, .,,Fe« + J £)O l »(OH) 1 l‘«-*

2.87

(K,^,Na.. w )o + &**

+ 0.18 - 1.26

[(AUiiTVijFe^i* FPyjpMgi jaMnoM) (SI,.7,A1 i j,) Oio(OH),) -1 ® 7
2.77

(K e .M,Nao.M,Ca/2o.i»)*oi 0 ®
+ 0.28 - 1.28

[(Alo.„TfajiFeojgFe^T a Mgi».i»Mne^) (Si,. 7< Al, ,»)0„(0H),]-*«

2.83

(K,j, < Na..„ t Ca/2, J »)5ar

These formulas also serve to illustrate the character-
istics of biotites from granodiorite: their generally low
octahedral A1 content, their fairly low Fe +3 content,
and their moderately high TiO } content. In these
biotites, as in those from granite and quartz monzonite,
adjustment for the additional charges carried by these
trivalent and quadrivalent octahedral cations is made
almost equally by method A and method B, except for
two, as in the second formula above, in which adjust-
ment is predominately by method B.

Biotites from diorite and quartz diorite. — The points
representing biotites from diorite and quartz diorite
occupy an elongated area (qd) on the middle right side
of the granite area in figure 12, most of the area being
below the Mg:Fe +a = 1 :1 line. This group also contains
both Mg and Fc +a dominant individuals, but 5 of the 7
in the group are Fe +a dominant. However, in neither
the Mg or Fe +a dominant individuals is the dominance
extreme, as is illustrated by these formulas of analyses
(53 and 101, table 11) which represent the Mg and Fe +a
extremes of the group

+0 JO - 1.26

( (AU.wTiajtFeajiFc^iiMgijiMnoji) (Si, .j*Al, .*) Ou(OH

2.88

(K« j«,Na«.i>i,Ca/2t.oi) "olS

+ 0.61 - 1.84

t(AI < , J ,Ti < ,.,,Ffja»FeaNfg,. > ,Mr^) (8i,.,.Al,. M )O l ,(OH) > F»-*

2.83

(K*j6,Na*.n,Ca/2i.*) + 15?

The Mg dominant members of the group contain con-
siderable Fe +a , and the Fe +a dominant members contain
considerable Mg although Fe +a may be more dominant
in some Fe +a dominant members than Mg is in any of
the Mg dominant members. These two formulas also
illustrate the extremes of octahedral aluminum content
in members of the group. The Fe,0, content of 5 of
the 7 biotites in this group was less than 1 percent. The
biotite represented by the formula for 101 above has
the highest Fe a O, content, 3.49 percent. Adjustment
for the additional positive charges carried by trivalent
octahedral cations in these biotites is, in general, fairly
evenly distributed between method A and method B.

The one point representing biotite from diorite falls
not in the quartz diorite area (qd) but near the top of the
granite area. This biotite is more dominantly magne-
sian than other biotites from diorite and quartz diorite,
but is not unlike them in other compositional char-
acteristics.

Biotites from nepheline syenite. — The biotites from
nepheline syenite are definitely more ferroan than the
biotites heretofore considered. The almost round area
(ns) in figure 12 enclosing points representing biotites
in this group lies well below the Mg-Fe +a =l:l line,
with the upper edge just touching the lower edge of
the granodiorite area (gd). The formula calculated
for analysis 109, table 11

+ 0.48 - 1.42

KAUWTi. nFe&Fe&Mgo.u) (Si,.«Al 1 . o )0 w (0H) I )-«-"

2.78

(K,.„,Na,.„,Ca/2o.«) + $:8

fairly well represents the general characteristics of the
members of this group, which are quite uniform in
composition. Octahedral A1 is very low. In some
members there is not enough to complete the filling of
the tetrahedral group, and some Fe +a must be allocated
to this group for its completion. The Fe^O, content
is generally fairly high, varying between 4 and 10 per-
cent in the analyses at hand. Mn is considerably
higher than in the biotites heretofore studied, several
of the nepheline syenite biotites having between 2 and
3 percent MnO. TiO, content is quite variable. Al-
though in a few biotites in this group adjustment for
additional positive octahedral charges is made equally
by the two methods, in most the adjustment is domi-
nantly by method B. Thus, many of the formulas for
this group are characterized by a low positive octa-
hedral charge, with fewer octahedral positions occupied
than in the biotites heretofore considered.

Biotites from gneiss and schist. — Points representing
biotites from gneiss and schist occupy an area in figure
12 which lies athwart the lower part of the granodiorite

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGT

(gd) area, the middle of the quartz diorite (qd) area, and
the upper part of the nepheline syenite (ns) area. This
location indicates that the biotites from gneiss and
schist are somewhat higher in Fe + * content than the
biotites from granodiorite, but generally lower in Fe +S
content than biotites from nepheline syenite. The for-
mula calculated for analysis 86, table 11, represents
the general character of the biotites in this group :

*f0^3 — l &

KAU Jt Ti,. w Fe 0 ^Fe 1 + 1 iMft > .„Mno^) (Sii. t< Al,^)0,o(OH) a )-»-«

X76

(Ko4»,Na«.n,Ca/2*.tt) + i;o7

These biotites are all Fe + * dominant, with moderate
octahedral A1 content and fairly low Fc +S content. Ad-
justment for additional positive octahedral cations is
made about equally by methods A and B, with a mod-
erate octahedral positive charge (0.30-.40), a moderate
negative tetrahedral charge in excess of 1.00, and with
an octahedral occupancy deficiency of about 0.2
position.

Biotites from pegmatite . — Of 14 analyses of micas from
pegmatite, only 4 represented biotites; all the others
represented Mg deficient trioctahedral micas, sidero-
phyllites, lepidomelanes, and intermediates of these.
Three of the four biotites from pegmatite are highly
Mg dominant and are lower in Fe + * than any of the
biotites from granite or granodiorite. Thus, the points
representing them in figure 12 fall outside the upper
boundary of the granite area. The fourth biotite from
pegmatite is highly Fe +1 dominant. The point repre-
senting it falls just outside the granite area on the lower
right side of figure 12.

Trioctahedral micas from pegmatite . — Ten of the four-
teen analyses of micas from pegmatites are very low in
Mg «1.5 percent MgO) and high in Fe +J content.
They therefore represent the Mg deficient end of the
Mg replacement system and occupy an area at the bot-
tom of the triangular diagram shown in figure 12. Two
of these analyses represent siderophyllites, with Al the
greatly dominant trivalent octahedral cation, and with
Fe +3 very low or absent; five represent lepidomelanes,
with Fe +3 the greatly dominant trivalent octahedral
cation, and with Al very low or absent. The other
three analyses represent aluminian lepidomelanes, with
significant amounts of both Fe +3 and octahedral Al,
but with Fe + * present in somewhat greater amounts
than octahedral Al. The three micas from nepheline
syenite pegmatite are, however, quite similar in compo-
sition, like biotites from nepheline syenite, and like

them are characterized by iron. The Mg content in the
micas from nepheline syenite pegmatite is, however,
very much lower. All three of these micas (124, 125,
and 126) are lepidomelanes, with octahedral Al very
low or absent. In one the Al is so low that there is not
sufficient to complete the filling of the tetrahedral group,
making it necessary to assign some Fe 43 to that group.

Li is reported in 7 of the 10 analyses of Mg deficient
trioctahedral micas from pegmatites, the amount re-
ported varying from 0.08 to 1.01 percent Li,0. No Li
is reported in the three analyses from nepheline syenite
pegmatite. This failure to report Li does not mean,
necessarily, that Li is not present. Li, if present, but
not determined, is reported as Na. As Li is considered
an octahedral cation and calculated as such, failure to
determine Li if present causes a double error in the
formula calculation, too few octahedral cations and too
many interlayer cations, the amount of error depending
on the amount of Li presont. In one of the formulas
calculated from the three analyses in which Li is not
reported, 126, table 11, the higher interlayer cation
content, 1.11, suggests tho possible presence of Li. In
the other two formulas calculated from analyses in
which Li is not reported, the interlayer cation content
is not high, but this does not rule out the possible pres-
ence of small amounts of Li.

Other Mg-deficient trioctahedral micas . — Of the 3 other
analyses of Mg deficient trioctahedral micas at hand, 2
are of micas from greisen, and 1 is of mica from offshoot
veins of trap dike. One of the two micas from greisen
is a siderophyllite, with less than 1 percent of FejOj, the
other is about halfway between siderophj'llite and lepi-
domelane. Tho latter is reported to contain 0.39 per-
cent Li 2 0. No Li is reported in the siderophyllite,
but tho high interlayer ion content is suggestive of its
possible presenco. The mica from offshoot veins from
trap dike is an aluminian lepidomelane containing 0.59
percent LijO.

The Mg-deficient trioctahedral micas show a greater
tendency toward one-sided adjustment for the extra
charges carried by trivalent and quadrivalent octahedral
cations than do the biotites. Of tho 13 Mg deficient
trioctahedral micas here considered, 8 showed prefer-
ential adjustment, 75 porcent or more, by method B.
In three the adjustment is entirely by method B, except
for compensation due to Li.

Li, with its single positive charge, compensates for as
many extra charges carried by trivalent octahedral
cations as the number of octahedral positions it occu-
pies. This may be illustrated by referring to the formula
for D63, table 12,

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

-0.03

l( A I* VctSt M go .« M no,o« Li».i i)

2.61

-1.03

(Si,., Al, .«) O„(OH) 1 ]->«K 1 + 0 , i 01

+0.27

-1.37

l(AI [ i.(nTi«.nFc 0 j;i , \ , o W Mg l .»Mn^03)(Si,.7,Ali J7) Oio(OH)if“ lw

200

(K.NatfS,"

In this formula Al and Fe + * carry 1.14 positive charges
in excess of the number of positive charges that would
be carried by the same number of bivalent cations.
On the other hand, 0.18 Li carries only half as many
positive charges as would be carried by the same number
of bivalent cations. Thus the zLi cations compensate
for x R +s cations, the number of extra positive charges
carried by the trivalent. cations is reduced by the number
of positions occupied by Li, and the layer structure
must adjust for 0.96 extra charges, not 1.14. This
adjustment is made entirely by method B, that is,
unoccupancy of octahedral positions, with the anionic
charges associated with these unoccupied positions
available for the neutralization of the extra charges.
Octahedral occupancy is only 2.51, the 0.49 unoccupied
positions contributing 0.98 negative charges for the
neutralization of the 0.96 extra positive charges, and
the octahedral layer is left with a residual charge of
— 0 . 02 .

DISCUSSION OF RELATION BETWEEN MICA COMPOSI-
TION AND OCCURRENCE

This study of the relation between the composition
and character of trioctahedral micas and their geologic
occurrence indicates that igneous rocks such as granites,
diorites, and nepheline syenites, and metamorphic
rocks, such as gneiss and schist, yield trioctahedral
micas in which both Mg and Fe + * are present in sig-
nificant amounts, that is, biotites, but do not yield
trioctahedral micas, like phiogopites, with very high
Mg content and low Fe + * content, or micas like
siderophyllites and lepidomelanes, with very low Mg
content and high Fe + * content. Heinrich (1946, p. 842,
844) found that phiogopites occur in pcridotites and
other ultramafic rocks and in metamorphosed lime-
stones. The data that are available on phiogopites
for the present study indicate that some phiogopites
are from contact zones of metamorphism. All the
siderophyllites and lepidomelanes are from pegmatites
or greisen. Thus the extreme types of trioctahedral
micas, those with extremely high or extremely low Mg
content, arc from extreme types of rocks.

There is not a clear distinction in the composition
of biotites from different kinds of rocks. This is illus-
trated by these three formulas, calculated from analyses
49, 50, and 51, table 11:

+0.31 -1.28

[ (Ah.o.Ti<,.„Fe < *AFc 0 4 g,Mfi, w Mno^) (Si,.nAli J ,)0„(OH),^«

zio

(K,Na,Ca/2)o-& #7

+ 0 . 2 * -IM

[ (AVwTU.ipFc^joFp^gaMfii .wMn^p,) (Si,.?»Al, j^OiofOH),)' 0 -**

Its

(K,Na,Ca/2) 0 + &“.

These formulas are essentially identical, not only in
the kinds and amounts of ions present, but in octa-
hedral charge and occupancy, tetrahedral charge, and
total charge. They are much more alike than many
calculated formulas for biotites not only from the
same kind of rock, but than some from the same rock
at the same location. Yet 49 represents a biotite from
granodiorite, 50 a biotite from monzonite, and 51 a
biotite from granite. Thus biotites from different rocks
may be very similar in composition and character.
That they are not differentiated clearly in character
is attested by the superimposing and overlapping of
areas in figure 12. At 1 place at the middle right-hand
side of the biotite area, the areas for 4 different rocks
are superimposed.

Conversely, biotites from the same kind of rock
may differ greatly in character and composition. This
is particularly true of biotites from granites and to a
lesser extent of biotites from granodiorite, diorite,
and quartz diorite. The diversity in composition and
character of biotites from granite is shown by the
large area occupied by these biotites, which embraces
practically the entire biotite area as shown in figure 11.
This picture, however, is probably distorted to some
extent by the loose usage of the term “granite” to
cover monzonite, quartz monzonite, granodiorite,
diorite, and quartz diorite.

The figures in Heinrich’s study (1946, p. 836-848)
of the relation between composition and geologic
occurrence in the biotite-phlogopite series seem to
indicate a more clear-cut differentiation between the
composition of biotites and their parent rocks than was
found in this study. However, he used a separate
diagram for each of his rock groups. If the diagrams
for his group 2 (granites, quartz monzonites, grano-
diorites), group 3 (tonalites, diorites), group 6 (syenites,
nepheline syenites, but excluding nepheline syenite

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Fiou*( 1*.— Rotation txitwwo the com portion »nd the grclostc ooeumrioo of biotites.
(After Heinrich, IMS, 0(3. 2, 3, 0, end 7 superimposed end reoriented.)

pegmatites), and group 7 (gneisses and schists), which
include all the groups shown in figure 12 except pegma-
tites and greisen, are superimposed on each other, as
in figure 13, it is found that the areas occupied by
biotites from these different rocks overlap considerably.
The tonalite-diorite area lies almost wholly within the
granite, quartz monzonite, granodiorite area, and half
of the gneiss-schist area overlies the same part of the
same area. Thus at this 1 place the areas for 3 groups
overlie each other. In figure 13 the triangular diagram
of Heinrich has also been reoriented, so that MgO,
FeO-fMnO, and FejO,-f TiOj occupy the same corners
with respect to the viewer as do Mg, Fe + *+Mn, and
R +, +Ti in figure 12. The occupied areas in the two
figures occur in the same general part of triangular
diagrams— a very good agreement in view of the
different methods used in plotting the biotite composi-
tions; Heinrich ’8 biotites being plotted on the basis
of percentage by analysis, in which octahedral A1 and
the great equivalent difference between Mg and Fe + *

is ignored, and the biotites in figure 12 being plotted
on the basis of octahedral positions occupied, including
octahedral Al.

However, correlations of this sort can show only the
broader aspects of the relation between biotite composi-
tion and the parent rocks; details of the relation are
possible only in more localized studies.

SUMMARY AND CONCLUSIONS

The composition of the trioctahedral micas can be
interpreted as derived from phlogopite, Mg,^o(Si,.ooAl)
0 1 o(OH)jK,.oo, by the proxying of other cations, par-
ticularly Fe +J , Fo + \ and Al, for Mg. Phlogopite, in its
ideal form may, therefore, be considered the prototype
of the trioctahedral micas, just as muscovite, in its
ideal form, is the prototype of the dioctahedral micas.
In natural phlogopites the proxying of other cations
for Mg is minor, and Mg is greatly predominant,
occupying more than 70 percent of the octahedral
positions. Progressively greater proxying of other
cations, particularly Fe +1 , for Mg leads successively to
Mg biotites, in which Mg is still the dominant octa-
hedral cation, but in which Fe +! is present in significant
amounts, Fe + * biotites, in which Fe + * is the dominant
octahedral cation, with Mg present in subordinate but
significant amounts, and siderophyllites and lepidome-
lanes, in which Mg is essentially absent, occupying
less than 5 percent of the octahedral positions. Thus,
in order of decreasing Mg content, the trioctahedral
micas, phlogopites, biotites, siderophyllites, and lepi-
domelanes form a complete system, from full octahedral
occupancy by Mg at one end to nil Mg occupancy at
the other end. These relations are expressed in the
following equations, which show the range in composi-
tion of three principal groups.

Phlogopite

Mg biotite
Fe +1 biotite

Siderophyllitca

and

lepidomelanes

<+0.30 (— 1.00)-(— l .30)

[( It<o.«Fc<o^ 0 Mgi.o > -,. M ) (Siai > vi.n,A]|. e o.,, B )0,a(OH),)~ l - w * >ia K(Na,Ca/2)i' f ( i,” 0 * 1 o <>

3.00-3.36

<+0.60 <— 1.00M— 1.60)

[ (Rft«-i.ooFe^j ) . 1 . tJ Mgi.rn.B )(Sl».t»3joAli.oM.io)Oi»(OH)3l~ l,<|:t!a - ia K(Na,C>/2)^”o!i <> d 10

290-2.M

<+0.60 (-1 .00M-1 .60)

t (Ro 4 A-, jW Fea- 1 . w M 8< ,.„Li,.„ ) (Si J .„.,.„Al 1 .« M .„) 0„(0H),1- “*»> a K (Na.Ca/^+^V 0
160-2.66

Considered as derivatives of phlogopite as the proto-
type, all trioctahedral micas exhibit multiple proxying
of other cations for Mg. The phlogopites are the only
trioctahedral micas in which one kind of cation is
greatly predominant in the octahedral group. Conse-
quently, the low Mg end of the system is represented

by siderophyllite and lepidomelane, not by annite, the
Fe +I analog of phlogopite.

The proxying of bivalent ions, like Fe + * or Mn +1 , for
Mg is ion for ion, and no layer charge adjustments are
necessary, but the proxying of trivalent ions, like Al,
or Fe +S , for Mg, because of their greater valence, re-

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INTERPRETATION OF TRIOCTAHEDRAL MICAS

quires layer charge adjustments. The two possible
types of adjustment may be expressed by the following
equations:

2nR + *=nR + *+7iSi (A)

2nR«=3nR + ». (B)

In the (A) type of adjustment nR +J ions proxy for
nMg ions in the octahedral layer, and an additional
nAl ion proxies for nSi ions in the tetrahedral layers.
Formulas for trioctahedral micas that have accommo-
dated trivalent octahedral cations in this way are char-
acterized by a positive octahedral charge equivalent to
the number of trivalent octahedral cations present, a
negative tetrahedral charge greater than 1.00 by an
amount equivalent to the positive octahedral charge,
that is, to the number of trivalent octahedral cations,
and by full octahedral occupancy. In the (B) type of
adjustment 2nR + * cations proxy for 3nMg ions. For-
mulas for trioctahedral micas that have accommodated
trivalent octahedral cations in this way are character-
ized by a neutral octahedral layer, and a negative tet-
rahedral charge of 1.00 as in the ideal formula for
phlogopite, but octahedral occupancy is deficient by
an amount equivalent to one-half the number of triva-
lent octahedral cations. A few formulas for triocta-
hedral micas have the octahedral positive charge, the
equivalently greater negative tetrahedral charge, and
the full octahedral occupancy indicative of the (A)
type of adjustment, and a few have the neutral octa-
hedral group and deficient octahedral occupancy of the
(B) type of adjustment, but most formulas for trioc-
tahedral micas have characteristics of both types of
adjustment — a positive octahedral charge, a negative
tetrahedral charge greater than 1.00, and octahedral
deficiency — indicating a combination of the two types
of adjustment. The relative degree of adjustment by

(A) or (B), and, consequently, the proxying ratio of
trivalent for bivalent octahedral cations varies. How-
ever, the average proxying ratio in the 250 formulas
included in this study is 0.73 A1 for 1.00 Mg, a proxy-
ing ratio which is considerably closer to that of the

(B) than to that of the (A) type of adjustment, indi-
cating generally greater adjustment by (B) than by (A).

In general, the degree of adjustment by (B) increases
with the octahedral R + ’ content. This is reflected in
a general decrease in the number of octahodral posi-
tions occupied with increase in octahedral R + * content,
with the average octahedral positive charge remaining
about the same throughout the octahedral R +s range.
Thus most trioctahedral micas are not truly triocta-
hedral. Nor are they true octaphyllites, as the number
of cations in the half cell is usually less than eight.

The trend of R +3 proxying is, therefore, toward mus-
covite or other dioctahedral mica. However, the dis-

tribution of the formulas studied over the R + * range,
and the scarcity of formulas having more 0.90 octahe-
dral positions occupied by R +l , strongly indicates that
the normal extent of R +> proxying for Mg is approxi-
mately one-third of the occupied octahedral positions
and that there is not a continuous series between the
trioctahedral and dioctahedral micas.

REFERENCES CITED

Clarke, F. W., 1903, Mineral analyses from the laboratories of
the United States Geological Survey 1880 to 1903: U. 8.
Geol. Survey Bull. 220, p. 77.

Cooke, J. P., Jr., 1867, On cryophyllite, a new mineral species of
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of Rockport, Mass.: Am. Jour. 8ci., 2d ser., v. 43, p.
217-230.

Dana, E. 8., 1892, The system of mineralogy, 6th ed.: New York,
John Wiley and Sons.

Dana, J. D., 1868, A system of mineralogy, 5th ed.: Now York,
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biotitee of the Carsphairn igneous complex: Mineralog.
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Eyerman, John, 1904, Contributions to mineralogy: Am.
Geologist, v. 34, p. 42-48.

Foster, M. D., 1951, The importance of the exchangeable mag-
nesium and cation-exchange capacity in the study of mont-
morillonitic clays: Am. Mineralogist, v. 36, p. 717-730.

1956, Correlation of dioctahedral potassium micas on the

basis of their charge relations: U. 8. Geol. Survey Bull.
1036-D, p. 67-67.

Grigoriev, D. P., 1935, Study of magnesium-iron micas: Soc.
Ruase minerdlogie M6m., ser. 2, v. 64, p. 21-79. [Russian
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mica group II. The basic micas: Mineralog. Mag., v. 21,
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Hamilton, 8. Harbert, 1899, Exploration of the Delaware Valley:
The Mineral Collector, v. 6, p. 117-122.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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p. 23-79.

Simpson, E. S., 1932, Contributions to the mineralogy of Western

Australia — Series VIII: Royal Soc. W. Australia Jour., v.
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Winchell, A. N., 1925, Studies in the mica group: Am. Jour. Sci.,
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Winchell, A. N., and Winchell, H., 1951, Elements of optical
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Table 11 . — Analytes and data for writing formulas of trioctahedral micas used in correlation study
[In order of docrwutng MgO oomeat]

INTERPRETATION OF TRIOCTAHEDRAL MICAS 41

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TT 1 ' " '7' i '77' " ' '7' ' 1 7 1 TT77 1 7TT 1 '777777 iTTTTTT 1 7TT '7 1 1 " 1 "7f7't' '77777

1 !

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Jail

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s = fs a n

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Digitized by Google

See footnote* at end of table, p. 43.

Table 11. — Analyse! and data for writing formulas of trioctahedral micas used in correlation study — -Continued

(In atom of ducrmrinj: MsO eontcnt)

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Locality amt reference for analyses in table It

1. DeKalb, N.Y., Dana. K 8., 1892. The system of mineralogy, 64b ed. t New York.

John Wiley and Sons. n. 633. No. II.

2. MansJO Mountain, Sweden, Eckermann, If. v„ 1085, Tsclicnnaks mtia dog.

petrog. Mitt., v. 3S. p. 28 1, No. 2.

3. Edwards. N.Y.. Dana, R. S„ 1N92. The system of mineralogy, 6th ed., New

York. John Wiley and Sons. p. 833, No. 4.

4. Oouvemeur, N.Y.. Dana. E. S., Ih.92. The system of mineralogy. 8th od., New

York, John Wiley and Sons, p. 833, No. 7.

5. Parr is, Finland, Dam. E. 8., 1892, The system of mineralogy, Oth in!.. Now

York, John Wiley and Sons. p. 833, No. 5.

6. Slvudlankrv, Balk iltn, U.S.S.R., Grigoriev, D. P., 1935, Soc. Kuuto mlnOra-

(ogie M5m. t 2d m., v. SI, p. 31, No. I.

7. Parg.v, Finland. Jnkoh, J.. 1932. Zelfschr. Kristallograpbie, v. 82, p. 273, No. 71.
7a. Snake Creek. Salt Lake City. Utah, Once!, J., 1023, Soc. Franc-dse mliwraloftlc

Bull., v. 48, p. 304. From phyllite.

8. Montvllto, N.J., Clarke. F. W.. PJ03. l*.S. CJcoI. Survey Bull. 220. p. 70, l>. C.

Cattdl, analyst. From serifontlno.

9. Jefferson. Wroomun Lake, Slate not riven. Kunltz, \V. t 1084. Neuc* Jahrb.

Miucraloglo, Geologic, u. Paltiontologlc, Bel Inge- Band SO, p. 412, table 2, No.

2 .

0a. Mansjtt Mountain, Sweden, Eckermann, If. v., ItCS, Tsehermuks mlncralog.
potrog. Mitt,, v. 38, p. 281.

10. Burgess, Ontario, Clarke. F. W„ and 8dllMldtf, E. A., 1W0, Am. Jour. 8d.,

3d ier„ r. 10, p. 411. E. A. Schneider, analyst.

11. Slyudianka, Buikulla. U.S.S.R., Grigoriev, D. P., 1035, Soc. Ru.w mlnAnriogie

M4>m.. 2d ser.. v. 64, p.3l, No. 5.

12. Deni. Idaho, Hietanen, A.. U.8. Geol. Survey Prof. Paper 314. in press.

13. U.8.8.R. (exact locality not Riven), Berkhln, S. I., 1951. Akad. Nauk SSSR

Doklady, v. 93, }>. 146. No. 800,

14. Slyudianka, Baikal!*, U.S.S.R.. Grigoriev, I). P., 1035, Soc. Russo. mfntratoglo

M4m. 2d scr., v. 64. p. 31. No. 3.

16. Easton, Pa., Eyerman, J.. 1001. Am. Geologist v. 34, p. 40, C.

10. Ration. Pa., Eyerman. J.. 1904, Am. Geologist V. 34, p. 4ft, A.

17. I«ake Baikal, U.8.8.R., Dana. E. S.. 1892. The system of mineralogy, Oth ed..

New York, John Wiley and Sons, p. No. I.

18. Slyudianka. Balkalla, U.S.S.R.. Grigoriev, D. P„ 1035, Soc Rustse mlnfratogle

M*m. 2d ser., v. 64, n. 31. No. 8.

10. Nancy Sound, New Zealand, Hutton. C. O.. 1947, Royal Soc. New Zealand
Trans., v. 7b, p. 488. In marble associated with fneftMO.

20. Southern Yakutia. U.8.9.R., Smlyuehinko. D. P., 1951, Akad. Nuuk SSSR

Doklady, v. 97. p. l!>2.

21. Northwest of Barkly West. Cape Province Africa, Nockolds. S. R.. 1917. Am.

Jour. Sel., v. 245. p. 413, No. *50. Associated with olivine and diopsidc augite.

22. Ludte llllls, Wyo., Hillebrnnd, W. P. p 1903, U.S. Geol. Survey Bull. 220, p. 76,

23. U.S.S.R. (exact locality not given), Berkhln, 8. I., 1954, Akad. N’auk SSSR

Doklady, v. US, p. 146, No. l.

24. Albnn Hills. near Rome. Italy. Washington, II. S., 1927, Am. Jour. 8ci. f 3th scr.

v. 14, p. 180. Associated with nephiiite-mellltlte rock.

25. Northern Caucasus, U.S.S.R., Serdyuchenko. D, P., 1951, Soc. Russe. min-

toalogie MOm.. v. 80, p. 175. Associated with dlopsldc, actlnollte, and al-
mandite.

26. U.S.S.R. (exact locality not given), Berkhln, S. I., 1954, Akad. Nauk SSSR

Doklady, v. 9ft, p. 146, No. 3.

27. Rossie, N.Y., Dana, E. 8.. 1892, The system of mineralogy, 6th od.. Now York,

N.Y., John Wiley and Sons. p. <33, No. 12.

28. Greenwood Furnace. N.J., Dana. E. 8., Tho system of mineralogy, 6th od..

New York, N.Y.. John Wiley and Son*, p. <00, No. 2.

29. U.S.S.R. (exact locality not given), Berkhln, 8. I„ 1954, Akad. Nauk SSSR

Doklady. v. 95. p. 146. No. 2.

30. Aiendal, Norway, Dana. E. 8., 1993, The system of mineralogy. 6th ed., New

York, N.Y., John Wiley mid 8ons,_p. 630. No. 10.

31. Storting. Tyrol, Dana. E. 1892, The sysieni of mineralogy, 6th ed„ Now

York. N.Y.. John Wiley and Sons. p. 630. No. 14.

32. Slyudianka, Bnlkalia. U.S.S.R., Grigoriev. D.P., 1935, Hoc. Rumo mtn(rok>glc

Mini. >1 ror.. v. t>4, p. 31, No. 9.

33. Bufumhlra, 8. W. Uganda, Combo, A. D., and Holmes. A., 1948, Royal Soc.

Edinburgh Trans, v. 61, p. 377.

34. Welnhdm. Germany. Weyberg, Z., 1912, Ncuef, Jnlirh. Min. B.B.I., p.396, No.

6 ». Associated with augite and rninettc.

35. Malvern. England. Tim HU, 1915. Mlncralog. Mag. v. 27, p. 139. From granite

pegmatite.

35*. FlUipstad. Sweden. Dana, K. 8., 1892, The system of mineralogy, 6th cd., New
York, N.Y., John Wiley and Son?, }>. 630, No. 13.

36. Ridgway, Va., Slovens, R. K., 1945, U.S. Geol. Survey Bull. 050, p. 118.

37. Monte Horn m a, Tuscany, Plorurcinl, R.. 1950, Soc. Toscana Sd. Nat. Alll

Mem., ser. A, vol. 57, p. 152. AsncuIm with plagiorlnsc and sanldine.

3S. San Juan district, Colo.. lessen, K. 8., Gonyer, F. A., anil Irving, J., Am.
Mineralogist, v. 22, |>. 902. Associated with pyroxene.

39. Kadautal. Germany, Kuultr, W. t 1936. Neuee Jahrb. Mlneralogle, Geologic u.

PahVmtologie Beibge-Band 70 A, p. 401.

40. Northern ClooiM, U.S.S.R., Scrdyuchenko, D. P., 1951, Soc. Riuoc Miner*

alngio Mfm„ v. 80. p. 176.

41. Koiatin, near Trebllf-, Moravia, Crochoslornkla. Dtidek, A., 1964, C?n.<ko*

slorcnsk5 Akad. V^J Rospravy. v. 04, p. 31. From arnphlholc-hiotite granite.

42. Kosov, near Jlhlava, Moravia, Cfcchaslovnklu. Dmlek. A., 1964. Onkoslo*

vcn.ska Akad. Vfd, Rorpravy, v. 64, n. 33. From pyroxenc-Motitc granite.

43. Monti di Duro, Italy, Jakob, 1931. Zeilschr. Kristallograpbie, v. 79. p.373,

no. 58.

44. Morven-Strontlan complex, northern Scotland, NockoMs, 8. R., and Mitchell,

K L., i‘>47. Royal Soc. Edinburgh Tran?., v. 61, p. 562, no. 5. Associated
with tonalltc-Rranodforlto.

45. ChocholowskA Valley, Tntm Mountain.?, Zastanmlnk, F., 1951, Soc. Gftol.

Pologne Anna let. v. 20, t>. 128. In diorlte.

46. Monti dl l>aro, Italy, Jakob, J., 1931, Zcitschr. Krlstallographic, v. 79, p. 373,

no. 67. H y

47. Zernovka, near kiftiny, Bohemia, rzechoelovakla. Dudek. A.. 1954. ('esko*

slovenskft Akad. V&l, Hoxpruvy. v. t>4. p. 27. From blotlte granite.

48. Bloods Station. Alpine County, Calif., Clarke. F. W„ 1903, U.8- Geol. Survey

Bull. 220, p. 75. r.. Associated with quartr.-montonitc.

49. Oamtxtf HlU-Qlon F>me complex, Scotland, Nockolds, S. R., and Mitchell,

R. L., 1947, RojtiI Soc. Edinburgh Trans., v. 61, p. 562, no. 14. From por-
phyrltlcgr&nodlorUc oontaminatorl with icdlmcntary material.

50. Ml. HotTman, Mariposn County, Calif., Clarke, F. W., 19C3. U.S. GcoJ.

Survey Bull. 23), p. 75, D. From quaitx-monxonlte.

51. Butte. Mont., Clarke, F. W., 19(0, U.8. Geol. Surrey Bull. 220. p. 75. G.

From granite.

52. Bethel. Vl., unpub. analysis by Charles Milton, U.S. Geol. 8urvey, lab. no.
, l) 953.

A3, obntake. KftxnvMora, Kuga-gdrl, Yamagutl Pref. Japan, Tsubol, S., 19W,
Jnjxmc»' Jour. Geology Geography, v. 15, p. 125, no. 24. In hypemheno-
blotlto-quartr. diorlte.

51. Senmaya, RtkutyG. Jaitun, Tsubol. S.. 1935, Japanese Jour. Geology Orography,
v. 12, i>. 112. no. 6. From hornblende-bearing blotlte gruuodioritc.

55. Yoko«lake. Euasin district, Mlno. Tsuboi, 8.. 1935, Japauene Jour. Geology

Geography, v. 12, p. 110, no. 9. In gnei.«oae grauiu*.

56. Old Point, Charles Sound, New Zealand. Hutton, C. O., 1947, Royal Soc. New

Zealand Trans, and Proc., v. 76, p. 482, no. 1. In p<ltmailtellkc lenses In
oligocbso-quartX'btotite gneia*.

57. River Tgftttt-WHU, Altai, Mongolia, Timofeev, K., 1927, Neue*. Jahrb.

Mincrulogle. Geologic u. Palftontologlc, Rrf. Bd. If, 81. From grunodtoritc.

58. Mm', near Bcncsov, Bohemia, Czcclioalovakla, Dudek, A., 1954, ^cskonlo*

venskA Akad. V6d Roipmvy, v. 64, p. 36. From amphibole-biotltfl grano*
diorlte.

50. Carsphairn complex. Southern Scotland. Deer, W. A., 1937, Mineralog. Mag.,

v. 24, p. 496, no. 3. From hornblende hybrid.

60. Ames Station, Belknap Mountains, N. If., Chapman, R. W., and Williams,

O. R., 1935. Am. Mineralogist, v. 20. p. 512, no. 2. From monxodiorlte.

61. El Capltan. Yasemlto V’allcy, Calif., hidings, J. P., 1911, Rock mineral?, 2d ed..

New York, John Wiley and Son?, p. 451.

62. Clove Valley. Dutches* County, N.Y., Barth F. W., 1936, Geol. Soc. America

Bull., v. 47. p. 783, no. 2. From contact between sheared quartxltlc schist
and pegmatite.

63. Tenryukyft.Slmolna-gfirl. Nagano Pref., Tsuboi. 8., 193?, Japanese Jour. Geology

Geography, v. 15, |». 12S, no. 28. In cnrdJerlte-blotlte homfels.

64. Rcnchthal, Germany, Dana. J. D., 1892, The system of mineralogy, 6th cd.,

New York, John Wiley and Son?, n. 630. no. 16.

65. Yowmitc Valley. Calif., Clarke, F. W., 1903, U.S. Geol. Survey Bull. 220, p 75,

C. From granite.

66. North fork of Mokelumne River above mouth of Bear River, Amador County,

Calif.. Clarke, P. W„ 1908, U.S. Geol. Survey Bull. 220, p. 75. F. From
pyroxene gneiss.

67. Islkawrv-matl. Hukuslma Prof.. Tsuboi. S., 1938. Japanese Jour. Geology Geog-

raphy. v. 16, p. 129. no. 31. In gnelswwe hornnlendr-blotltcjfr.modlorlte.

•tS. Akonaka, Soniekawa-mura, IIIgatLxirakawa^ftri. Hukusima Prof., Tsuobi. S.,
1WS. J;q>ane.*c Jour. Geology Geography, v. 15. p. 125, no. 19. In gnclsaoso
tomdite.

69. Freiburg, Germany, Becker, A., 1890, Zeitschr. Kristallograpbie, v. 17, p. 129.

From gneiss.

70. Mora, Minnesota, Grout, P. F., 1924, Am. Mineralogist, v. 9, p. 160, no. 3. In

granlto.

71. U.S.S.R. (exact locality not given), Berkhln. 8. 1., 1954, Akad. Nnuk SSSR

Doklady. v. 95, p. 146. no. loti.

72. Monterey Buy, Calif., Gulllhrr, E. W., 1935, Geol. Soc. America Bull., t. 46,

p. 1359. From granite.

73. Minedera, near Tokyo. Japan, Kawano, Y.. 1933, Imp. Acad. Tokyo Proc.,

v. 9, p. 610. In iK»rphyrltlc blotlte granite.

74. Glen Bucket, Aberdeenshire, Scotland, Walker, O. F., 1W9, Mlncralog. Mag.,

v. 28, p. 698, no. 1. From hypenthene gnbbTO.

75. F.hrvriberg, Germany, Kunltx, W., 1929, Zeltschr. Krlstollogruphie. v. 70, p. 512.

From monzonito.

76. liira?awa, Oda Mura, Tukuba gSri. Iborakl Pref., Tsuboi, 8., 1038, Japanese

Jour. Geology Geography, v. 15. p. 126, no. 21. Large xenollth enclotied in
blotlte granite.

77. Taknto, slnano, Japan. Tsuboi, 8., 1935, Japanese Jour. Geology Geography,

v. 12. p. 110, no. 8. From blotlte granodiorlte.

78. Trnryflkyft, Slmoin.-vg&d, Nagano Pref.. H'subol, S., 1938. Japan Jour. Geology

Geography, v. I6, p. 126. no. 23. In blotlte gneiss (Inkcilon gneiss).

70. CheMtnut Ridge, Dutches* County, N.Y.. Barth. K W., 1036, Geol. Soc.

America Bull., v. 47. p. 783, no. 1. From black phylllte.

80. Southwestern Finland, Hletanen, A.. 1943, Acad. Sel. Fenn. Annates, aer. A.

III. G«sdoglru-Geographlca., no. 6, p. is. From diorlte trondh)emite.

51. Eight mile* northwest of Ouster, 8. I)ak., Wells, R. C., 1937, U.S. Geol. Survey

Bull. S78, p. 99. From i>rgmatlte.

82. I’plngton, Ca|H‘ Province. South Africa, Mathias. M.. 1952, Mlncralog. Mag.,

v. 29, p. 939. From cordlerite rock.

83. Carsphalrn complex, southern Srotland, Deer, W. A., 1937, Mlnerulog. Mag.,

v. 24, p 4U6. From granite of a complex intrusive.

84. lAven Island, Kunltx, w„ 1929, Zeltscnr. Krlstalkigraphle, v. 70, p. 512. From

nephelluc syenite.

85. Karnrnx. Germany, Kunltx, W., 1929, Zcltschr. Krbtallogruphh*, v. 70, p. 512.

From granodiorlte.

86. Ornnk, Tatra Mountains, Zastawnlak, F.. 1951, Rocxnik Folsk. Towarz. Geol.,

v. 20 (1950), p. 129. From Injection gneiss.

87. Mukuno, Karaano-mura, Oslma-gftri, Yamagutl Prof., Tsuboi, S., 1908, Japanese

Jour. Geology Geography, v. 15, p. 127. no. 25. In gamet-beorlng schistose
htotlteKiuartx dtortte.

$8. Monsjo Mountain, Sweden. Eckcrmonn, if. v., 1925, Tschcrmaks mlncralog.
ftetrog. Mitt., v. 38, p. 277. From contact zone of ficgumtltv Intrusive Into
eulynic and limestone.

89. Usugl, Takanuki district, Iwakl. Tsuboi. 8.. 1935. Japanc** Jour. Oeology

Gn>graphy, v. 12, p. 112, no. 5. In garnet-bearing gnolwse blotlte granlto
(contaminated rock).

90. Altai. Mongolia, Timofeev, K., 1927, Ncues Jahrb. Mlneralogle. Geologic U.

PalOontologle, Ref., v. u. p. HI. From granodiorlte.

91. Kanuitu-matl, Oslma*g6rt, Yamagutl Pref., Tsuboi, 8., Juj»ne*e Jour. Geology

Orography, v. 15, p. 127, no. 26. In jnumrt-bcarlng bk»t lie-quartz diorlte.

92. Kazl^btua. Illdumbmura, Ktiga*gftei,Yam*KUtl Prof., Tsuboi, 8., ! 938. Japanese

Jour, flrology Geography, v. 15, p. 127. no. 27. In blotlte gneiss (injection
gneiss).

93. Kuma DUnd, Los Archipelago, Kunltx, W„ 1929, Zeltschr. Kristallograpbie, v.

70, p. 512. From ncphcllne syentte.

91. Takanuki district, Iwakl, Tsul*oi, S., 193.5. Japanese Jour. Gaotogy Orography,
v. 12. p. 112, no. 4. From Injection blotlte gnclsc.

95. Stewart Island, New Zealand. Williams, G. J., 1934, Geol. Soc. London Quart.
Jour., v. 90, p. 336. From granite.

90. Faraday Township, Hastings County, Ontario. Canada, Walker, T. L., and
Parsons, A. L., 1926, Toronto Unlv. Studies, Geol. acr., no. 22, p. 22. From
DopbtliM tnrenlte.

97. Beihelvta, Abcrdcenshlro. Srotlond, Stewart, F. II. , 1012, Mlncralog. Mug.,
v. 26, p. 263. From 8lOi poor bornfcls.

Digitized by Google

INTERPRETATION OF TRIOCTAHEDRAL MICAS

Locality and reference for analyse* in table II — Continued

98. t’sugt, Taknmikl district, Iwnkl, Tsubol, R.. IftU, Japanese Jour. Geology

OfORrftphy, v. 12, p. 112. From unrinnio blolile-granllc.

99. Rlsiok, Kola Peninsula, U.8.B.R., Ivanov, 15. V.. IW7, Akad. Nuuk 8S8R

Lomono9ovskii Instllut <JeokliliniE. KrlstuHogruphll 1 Mlneralogll Trudy,
no. 10. i>. 43. From peg nun Ite and mtca-nepheune syenite.

100. Brevlk. Norway, Kunltz, W., 1024, Notice. Juhrh. Mlneralogle, Geologk* u.

Palkontologte, Bell. -Band 50, p. 413. Probably wsocftateu with ncRirlne,
nephellne syenite pegmatite.

101. ProsecnUt* near Praha. Bohemia, Czechoslovakia, Dudck, A., 1054, Vesko*

slovcuskft Akad. VSd Rozpmvy, v. 64, p. 20. From Idotltle grunodlorltc.
lfC. Mariupol. Sea of Azov, U.8.8.R., Morozewlcz J., 1880, TScbermak* Mlnendog.

Petrof. Mitt., v. 40, p. 374. From marlupollte.

1(0. Dermone. Hulland, Sweden. Wlman, K., 1W0, 1’pwU Unlv., 0«l. Inst., Bull.,
22, p. 06. From f>egmntttc containing mlemcline, quartz, ami nIMte.

104, Illramwa, Oda*inurl, Tukubu-gurl, Itaraki Pro/.. Tsubol, S., 1038. Japanese
Jour, (leology Geography, v. 15. p. 125, no. 20. From hkilltc granite.

106. Fukushlnzan dblrkt. central Korea, Inoue, T., 1050, Urol. t#oe» Julian Jour.,
v. 5$, p. 76. From nephellne syenite.

106. Rockville, Minnesota, Grout, F. r„ IU24, Am. Mineralogist, v. 9, p. 161. From

granite.

107. Ranagemuro, Nlsl-Knmo-gdri, Alt! Pref., Tsubol, S.. 1936. Japanese Jour.

Geology Geography, v. 13, p. 335, no. 15. From Motile granite.

108. Wldccombe. Dartmoor, England. Bruminall, A., and Harwood, II. F„ IW2,

Geol. Soc. London Quart. Jour., v. Sb, p. 234. From dark veinlet in granite.

109. Minsk, Ural Mountains, U.S.8.R., Kuuitz, W„ 1924, Noiies Jnlirb. Mlucrulogie,

(Irfilogio u. Paliiontologle Bell. 'Band 50, p. 413. From ncptiellne syenite.

110. Saddle Tor, Dartmoor, England, Brammall. A., and Harwood. II. F.. 1932.

Geol. Soc. I-ondon Quart. Jour., v. 88, p. 231. From granite; a&ockited with
muscovite.

111. llatu, Tuba-mom, Kuga-g&rl, Yamagutf PnC Tsubol, S.. 10.58, Japanese Jour.

Geology Geography, v. 15, p. 128, no. 29. From cranodlorUe.

112. Fukushlnzan District, central Korea, Inoue, T., i860, Geol. Soc. Jupan Jour.,

v. 5*5. p. 76. From nephellne syenite.

113. llaytor quarry. Dartmoor, England, Brammal), A., and Harwood. H. F.. 1923,

Mlneralog. Mag., v. 20. p. 23. From granite.

114. TenryQkyo, Simoina-gftrl, Nagano Pref.. Tsubol, S.. 1938. Japanese Jour. Geol-

ogy Geography, v. 16, p. 126, no. 22. From porphyrlto schistose hornblende*
btotlie granite.

115. Minsk, Ural Mountains, U.S.8.R., Dana, F.. S.. 1892, The system of :ntu< rnlogy,

tub rd.. New York, John Wiley and Sons, t>. 630. no. 22.

116. Tutiyanr, Nudo-cmru, Kuga-gOri. Kamnguti Pref.. Tsubol. S., 19». Japanese

Jour. Geology Geography, v. 13, p. 335, no. 14. From hornblende-bear lug
blotlte granite.

117. Near Beech Hill, Percy quadrangle, N.H., Chapman, K. W., and Williams,

(\ R.. 1935. Am. Mineralogist, v. 30, p. 512. From grunlte.

118. Unlcr-WaW-MlchellKwh, OdenwoIdL Germany, Klcmm, 0„ 1926, Verolns fur

Erdkunde un<l der llcfSbchcn Ocologlschcn L»ndrs.mstalt zu Darmstadt
Notizhlntt. 5th scr., No. 8, p. 160. Associated with muscovite, adamellite.

119. Sweltor quarry. East Dartmoor, England. Brammall. A., and Harwood, n. F..

1932, Geol. 8oe. London Quart. Jour., v. 88, p. 254. From granite.

120. Near Iwakuru Hallway Station, Og6rl, Yamagutl Pref., TbudoI. 8.. 183>\ Jap-

anese Jour. Geology Geography, v. 13. t». 334. no, 13. From hiotlte grande.

121. Prison quarry, Princeton, Dartmoor, England, Hmmmnll, A„ and Harwood,

II. F„ 1932, Geol. Six;. London Quart. Jour., v. 88, p. 234. From gmnite;
associated with muscovite.

122. Laltiln. Finlund, Kskola. P.. 1940, Comm. Geol. F inlands Bull., v. 23, p. 114.

From fresh rapttkivl (“morn”).

123. Ikka, Kukushlma Prof.,8blbata,If., 1952, Tokyo Bunrlka Dtlfaku 8d. ropes.,

v. 2. sec. C, no. 12, p. 162, no. 8. From graphic granite pegmatite.

124. French River, Sudbury district, Ontario, Canada, Walker, T. L., and Parsons,

A. L„ 1926, Toronto Unlv. Studies, Geol. kt. no. 22, p. 8. From nephellne
syenite pegmatite.

125. Wausau, Wisconsin. Wcldman, S., 1W7. Wisconsin Geol. and Not. History

Survey Bull. 16. p. 295. From quartz syenite pegmatite.

126. Mount Royal, Quetiec. Canada, Hnley. F. L., 1930, Canadian Jour. Research,

v. 2, p. 236. Associated with aeglrlne. nephellne syenite pegmatite,

127. Kbisu aline. Nsveg: district, Japan. Shihata. H., 1962, Tokyo Bunrika I)aig«ku

Sci. Repls., v. 2, sec. C, no. 12. p. 162, no. 6. In gmscil.

1%. Hiicltlnmn, Nnegi district, Japan. Sliibula. II., 1952. Tokyo Bunrika Duigaku
Sci. Kept*., v. 2, sec. C, no. 12. p. 161, no. 2. In pegmatite.

129. Mournc Mountains, New Castle County, Ireland, Nockokb, 8. R., and Richey,

J. K., 1939, Am. Jour. Scl., v. 237, p. 38. In gnucen veins cutting apllte veins
in granite.

130. Huchirnnn. Nivrgi district, Ju|un. Shihata. H., 1952, Tokyo Bunrika Dalgaku

Sci. Rcpta., v. 2. sc c. C. no. 12. p. 161, no. 3. In |>cgmutilc.

131. lluchimu:i. Nucgi district, Japan. Shihata. II.. 1952. Tokyo Bunrika Dalgaku

Sd. Rents., v. 2. sec. C, no. 10, p. 114. In granite pegmatite.

132. Brooks Mountain, Alaska, Coates. K. R.. and Fahey, J. J., 1944, Am. Mineralo-

gist. v. 29, p. 373. From pegmatite rdll intrusive into granite.

133. Volhynia, U.S.S.R., Buryanova, K. 7... 1910, Soc. Rusn Min/xnlogie, Mem.,

V. ffj, n. 532.

134. lisaku. FukusMma Prof.. Ju|Km. Shihata. 11.. 1952. Tokyo Bunrika Dulgaku

8d. Repts., v. ?, fee. C, no. 12. p. 162. no. 9. Ju groiseu.

135. Yagcnyama. Jnixan, Rhlhuta, H., 1952, Tokyo Bunrika Dalgaku Scl. Repts.,

v. 2., sec. C, no. 12, p. 162, no. 7. In grcltien.

Digitized by Google

Table 12. — Analyse* and data for writing formulas of trioctahedral micas not used in correlation study

(In ardor of docnrnslnc MgO contont)

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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Digitized by Google

INTERPRETATION OF TRIOCTAHEDRAL MICAS

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Digitized by Google

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Locality and reference for analyses in table 13

Dl. Edwards. St. Lawranoft County, N.Y., Clarke, F. W., 1910, U.8. Gool. 8unroy
Bull. 419. p. 289. A.

D2. MansjO Mountains. Sweden. Kckermann, H. v., 1925. Tschcrnuiks mlnerulog.,
petrog MUt.. v. 38, p. 281. From contact tone of pegmatite Intrusive Into
culyslte and limestone.

D3. Edwards, St. Lawrence County, N.Y., Peofleld, S. L., and Sperry, E. S.,
1888. Am. Jour. Sci., 3d $er., v. 3fi, p. 330.

D4. Penmvllle. Pa.. Dana. E. S.. 1892. The system of mineralogy, 0th ed., Now
York. John Wiley and Sons, p. 633, no. 8.

1)5. Monte Bracelo, Val Matenoo. Italy. Puclloiil, O., 1910, Soc. Ital. Sci. Nat.
Milano, Attl., v. 79, o. 21. In limestone.

D6. Rossle, 8t. Lawrence County, N.Y.. Dana, E. S., 1888. The system of miner-
alogy, flth ed.. New York. John Wiley and Sons, p. 633. no. 6.

D7. Parra*. Finland. Dana, E. 5., 1893, The system of mineralogy, Cth ed.. New
York. John Wiley and Sons, p. <33. no. I.

D$. Baikal la, U.S.S.R., Grigoriev, I). I\, isos, Soc. Rusk MinOralogk* Mfm.,
v. w. aer. 2. p. 31. no. 2.

I>9. MansJO Mountains. Sweden. Eckennaun. II. v., 1025, Tscherinnk* miners log.
petroi! MUt.. v. 3S, p. 281. From contact tone of pegmatite Intrusive into
oulyslte and limestone.

DlO. Morawitu, Hungary. Dana. F.. S., 1892. The system of mineralogy. 6th ed.,
New York. John Wiley and Sons, n. 630. no. 5. In magnetite.

1)11. Slludtanka. Lake Baikal. U.S.S.R., Grigoriev, I>. P., 1935, Soc. Ka&e Mlnfr-
alogie M6ui. v. 61. tier. 2, p. 31, uo. 6.

D12. U.8.8.R. (exact locality not given), Berkhln, S. I., li«M, Aknd. Nauk 8SSU
Doklady, v. 95, p. 146, no. 48.

D13. Ambutcubo, Madagascar. Jakob, J., and Purgu-Pondul, I., 1932, ZciLichr.
KrUtallographte. v. 82, p. 273. no. 62.

Dl4. MonzonS, South Tyrol, Italy, liana, E. 8.. 1692, The system of mineralogy,
fith ed., New Yorlc. John Wiley and Sons, p. 630, no. 4.

D15. Sllndbnku. Iaike Baikal. C.S.S.fc., Grigoriev, 1). p„ 1935. Soc. Ru»c. Mlnfr-
alogle M6:n. v. 64. p. 31, no. 7.

D16. Fortuna, Murcia. Spain. O&mn, A.. 1906, Kascnlmsch Festschrift, p. 271.
Associated with olivine and autlte, verlte.

1)17. Vesuvius, Italy, Bcrworth, F., 1677. M lnemlogtachc Mlttcllungen. p. 112. no. i).

DlS. Bobchll Lahy, North Caucasus, U.S.S.R.. Serdluchvnko. I> I*.. 1951. Soc.
Russo Mlntraloglc M6m., v. 80, rer. 2, p. 177. In gmnlto-apllte vein cutting
through aententinr.

D19. Muturczlma. Janun, Kozu, S., and Tsuruml, S.. 1931, Japonew Assoc. Miner-
alogists. Petrologlsts and Ecnn. Geologist* Jour.. v. A. p. I V).

1)20. Laurel Creek mine, Rabun County. Ga.. Clarke, F. W.. 1912, 17.8. Ge^l.
Survey Bull. 419. p. 2>9. B. From corundum mine.

D21. Smith ltldgc, Boebls Butte Quadrangle, Idaho. Ilietam n. A.. 19V). Am.
Mineralogist, v. 41, p. 7. From kyanlU-andalusItesililinanllc-cordlerile
gneiss.

D22. Tatra Mountains, Czechoslovak la, Weybcrg, Z , 1912. New* Jahrh. Mtncr-
alogle. Geologic u. I’aliUmialoglc, pi. I, p. 39s. Probably ;LVwl:it»’d with
uugitc, kcnunlite.

1)23. Cheborku), southern Urals. U.S.S.R., Diuu. E. 8., 1892. The system of
mineralogy, 6th ed.. New York. John Wiley and Sons. p. 630. no. II.

I>23A. Morven-Strontlun complex. Scotland. NockoMs. S. R.. and MltcJwll. R. L.,
1947, Royal Soc. Edinburgh Trans., v. 61, p. £62. From gr.uiodlorlto.

D24. Odenwald. Germany. Kunltx, W„ 1936, Noues Jtxhrb. Mlncfaloqle. Geologic,
U. PulHontologlc. Bcllugc-hand, v. 70, Abt. A., p. 401. As«oclntod with
nngite and aecirine.

1)2.'. Hill of Stroue. Forfarshire, Scotland, Phlllipa. F. C., 1930, Mineralog. Mug.,
v. 22. p. 255. no. vlll.

1)26. Black Caacude, Trlpyramld Mountain, N.H., Chapman. It. W. t ami Wlllhims,
C. R.. 1955, Am. Mineralogist, V. 20. p. 512. From gab bio.

D27. Dowerin. Western Australia. Slinjwon. K. 8., 1931-32, Royal Soc. Western
Australia Jour., v. 18. p. 63. In negnratlte, associated with cummingtotiitc.
octlnollte, almandlne, andeslne feldspar, and chrysoberyl.

1)28. Katxvnbuckel. Odenwald. Germany. Freudenberg, W.. 1920. Badbchcn Geol.
Landesanstult, Mitt, v. 8. p. 321. From m Ica-no phellne i*irphyry.

D29. San Juan district. Colo.. Larsen. K. S., Oonyer. F. A., and Irving, J., 1937,
Am. Mineralogist, v. 22, p. 9C»2. From <iuart2-latite monzonlte.

1)30. Round Luke, near Kingston, Ontario, Love. W. T., 19(0, Koyul Sue. Canada
Tram., 3d ser.. v. 31. sec. 4. p. JS. From gneiss.

D31. Perslscrg. Sweden, Dana. E. S., 1892, The system of mineralogy. 6th ed.. New
York, John Wiley and Sons. p. 630, no. 15.

D32. Ctdnismore, southern Scotland. Deer, W. A., 1937, Mlncralog. Mag., v. 24,
p. 496. From tonalltc.

D33. RoM-shlrr, northwestern Scotland, Marker. R. I., 1954, Geol. Mag., v. 91.
ii. 452. From •‘cordk*r1lo M -blotlte -plaglocbwe homfels.

D34. llitlcro, Norway, Dana. E. S., Ihvti. The system of mineralogy, Cth ed. ( New
York, John \\ iley and Sana, p. 630. no. 17.

D35. Cowall. Argyllshire. Scotland. Phillips, F. C., 1930, Mlncralog. Mag., v. 22.
p. 254.

D36. Ketlla, Impitahtl, Finland, Mehmel, M„ 1937, Cbemlcdcr Erdo, v. It, p. 307.

1)37. Kuklsvurnchorr, Kola Peninsula, U.S.S.R., Ivanov, B. V., 1937. Akad. Nauk
SSSR Lomoncwovskll Instant Oookhlinll. Krlstallografil l Mlneralogii
Trudy, no. 10, p. 3s.

1)3$. Baltimore. Md., Clarke. F. W., 1903. IT.S. Geol. Survey Bull. 220. p. 77, E.

1)39. Cluru, Val del Molino, Tesaln, Italy. Jakob, J., 1931, Zcllschr. Krista llographlc.
v. 79. p. 373. !10. 59.

1)40 Val Pedcr, Italy, Tomba, A.M., 1952. Ace.vl. Nor. Ltncel Attl., rend., Cl.
Sci. fls. mat. not,. <er 8, v. 13. p. 80. Iiuiuslom in staurolitc In inloa schbt.

Dll. Clare, Val del Molino, T<«?ln, Italy, Jakob, J., 1931, Zeltschr. KrbtalloKraphte,
v. 79, p. 373, no. 60.

1)42. Sklddaw, Cmnbcrhuid, England, Ilitchen, C. 8., 1934, Geol. Soc., London,
Quart. Jour. v. 90. p. 173. From granite.

1>43. Tomanowu Valley, Tulru Mountains, Poland, ZaUuwtilok, F., 1951, Rocznlk
Polsk. Towar*. Geol., v. 20 (1950). u. 128. In gneiss.

I >44. l'orj Henry, New York, Clarke, F. W., K»03. U.8. Geol. Survey Bull. 2a). p.

D45. Koecista, East Tatra Mountains, Czechoslovak lo. Weyberg. Z.. 1912, Neucs
Jahrb. Mineraloglc, Geologic u. PalAontologln, pi. 1, p. 3 W. In granite.

D16. Lake Ilmen. Minsk, U.S.S.R., Dunn. E.S., 1892, Tlic system of mineralogy,
fith ed., New York. John Wiley and Sons. p. o3Ci, no. 12.

1)47. Ballyglhem, County Donegal, IreUml, Haughton, S., 1S59, Grol. Soc. I^ondon
Quart. Jour., v. 15, p. 131. In granite.

I>48. U.S.S.R. (exact locality not given), Ikvkhln, S. I., 1851, Akad. Nauk. SSSR
Doklady, v. 95, p. 146.

1)49. LiUKivtind Fiord, Norway, Dxma, E. 8., 1892, The system of mineralogy, fith
ed.. Now York. John Wiley and Sons, p. 63(. mi. 7.

D50. Iihikawu, Fiikushima, Prof. Japan, Yoahlko. B.. 1W3. Imp. Acn<l. Tokyo Proc.,
v. 9, p. 321. In pegmatite dikes traversing granite.

1>51. Ballyeiln, County Carlow, Ireland. Haughton, S., 1859. Geol. Soc. Ioxndon
Quart. Jour., v. 15, p. 130. In granite.

D52. Bavono, Italy, Cl tillUclII. P., IW, Perlodlco Mlneralogia. Roma. v. 7. p. G4.
In granite.

D53. Iluvcno, Italy, GiUUtLdM, P.. 195*., Perlodlco Mlneralogia Roma, v. 7, p. 64.
In gnuiite.

D5I. I taka, Japan. Shibatn, 11.. 1952, Tokyo Bumlku Daigaku Sci. Repps., v. 2,
sec. C.. no. 12. t». 163, no. Ifi.

D55. Maknbo Town, llwakll, prof. Japan, Shlbata. 11., 1962, Tokyo Hunrika
Daigoku Sci. Rcpts,, v. 2. <ee. C.. no. 12, n. 163. no. Ifi. From pegmatite.

1)50. Mcrrow I.edgc, Auburn, Maine, Clarke, F. W., 1903, U.S. Geol. Survey Bull.
220, p. 75. A. From quartz mouzonltc.

1)57. Yumanoo, Tsukubn. Japan. Shlbata, H.. 1952, Tokyo Bunrlka Duigaku Sci.
Repts., v. 2. sifcc. C., no. 10. p. 143. no. 15. From i>cgmatito.

D58. Helko-gun, Koiienalo, central Korea, luoue, T, 1950, Geol. Soc. Japan Jour.,
v. 50. p. 76.

I >59. Plkcw Peak. Colo., lajwb, IT. C., 1»0, Phllarlelphte Acad. Nat. Sol., Proc.,
v. 32. p. 264.

DUO. Brevlrk. Norway, Dana. E. S., 1866, The system of mineralogy, Cth e«l.. New
York. Joint Wiley and Sons. p. 634, no. 6.

1)61. Litchfield. Maine. Clarke. F. \V„ liM)3. U.S. Geol. Survey Bull. 220. t>. 77. A.

1X»2. ILsaka, Kukudilnut, Pref. Jnjmn. Shlbata. II., 1952. Tokyo Bunrlka Dutguku
Sci. Kept., v. 2. sec. C\. no. 10, p. 121. From gronlle |>egmatite.

D«3. Rock|XMt» Muss., Cooke. J. P„ Jr.. iwi7, Am. Jour. Sri. 2»l ser., v. 43. p. 225.

1X4. Jbuka, Fukushlmn, Pm. Japan, Shihatn, H., 1952, Tokyo Bunrlka Dalgaku
Sci. Rent., v. 2, sec. C.. ih». 10, |». 121. From granite iwgmatltc.

1)65. Mangunlde, Province Bclnt. Portugal, Mdrto do Jesus, A., 1933, Portugal,
Sm'kas Gaol., Cornun.. v. |o. p. 128.

D66. Kudaru Town, Nigeria, Bain, A. D. N., 1933, Geol. Soc. London, Quart. Jour.,
v. 90, p. 227. From granite.

D<»7. Volhvnla, U.S.S.R.. Buryanova, E. Z., 1940, Soc. Russo Mlncralog ie Mem.,
v. DO, p. :*32. From itcymatile In ravakivtllke granite.

1)68. Rockiwn, Mass., Clarke. F. W., IIMKJ, U. S. Gool. Survey Bull. 220, p. 77, C.
!u folds nut hie vein in granite.

DOO. Wermland, Bweslett, Dana, K. S., 1892. The system of minerulugy, fith H.,
New York, John Wiley and Sons, p. f*34, no. 1.

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INDEX

Page

Analyse ami formulas, excluded from study 15-16. id

US4H] in study 15.4142

Anionic compcdltUm of micas 14

Annltc, Dona's % 30

Wlnchell’s 24. 30. 31

Blotltes, average formula 29

average oetahedral composition . . 29

composition of, Holxuer’s hypotlxocs 12

Fc*> dominant .. 27 ifO

from d lor It* 35

from gnrtss and schist 36-36

from granite 33-34

from granodiorite 35

from monzonftc 34

from nephellue syenite 35

from pegmatite 36

from quartz dlorite 35

from quartz monzonlte 34

Mf -dominant 23.2H-29.3i

range of com petition &

selected data on, from Holznrr 22

Bivalent octahedral cations Hi, 17. 22

Cape Ann, Mass 29

Cationic composition of micas 14

Cations, bivalent octahedral 16. 17. 22

trivalent, accommodation of 12

In natural trloctaludral micas 13.22

Charge, calculation of 14

Charge#, accommodation of extra positive octahedral 16-22

Clarke, F. W 16

Cooke, J. P., Jr 2 L>

Page

Lcpidomelane, aluminian 32

Lrpidomelam*, representative formulas 31

Lithium, effect of. In formula cakmlation. .. Id

in sldorophyllit<«and loptdomelanes 3U

Magnesian hlotitcs 25.27

Magnesium, exchangeable in niontmorillonttcs 13

Interlayer positions 15

Magnesium replacement system 24 y»

Marshall, O. K U

Mg-drflcknt triocUhedral rnicu 26

Mg-dom Inant blot lies. 23.25.28

Mleus, anionic coni|x>sitlon U

composition and occurrence 32-38

dlulumlnum magnesium.... 2C.27

dlortahcdrul potassium 12

Intermediate between 8lder»phyllit<*s and Icipidomelonr#. 32

Po** dominant 18

layer charge relations, theoretieal 12-13

octahc<lm! group 12-15

MontinoriUonlu- 15

Muscovite, ideal formula 12

Nook olds. 8. R 30.31

Octahedral group 12. H. 15.33

Octahedral ocxti paiiy 20

Pauling, Linus 23

Phloffopllts. average formula 19

geologic occurrence 32.37

interlayer Mg 15

range In composition 2L»

Selected data front (lolzuer 2 2

Dana, E. 8 31

Dana. J. D ... 29

Deer, W. \ 23

Dlociahtdrul micas 12

Quadrivalent octahedral cations 17. 1 H, 19

Richey, J. K 30.31

Raw, C. S 15

Kastonlte, Simp<o:i’* formula 27

Wincbcir# formula 12.27

Extra positive ocluhcdm) charges. 16-22

Kyerman, John .21

Formulas, calculation of, from analyses of niontmorillonltc 15

Foster, M. D 12.13,15

Fe»» blotiteS 2!., 27. 28

Fc* 1 , tetrahedral 32

Formula, notation U

Formulas, calculation 13-16

Grigoriev, D. P 31,32

IIalf-cell formula . 14

HaUlmood, A. F 31

Hamilton, 3. Harbert 21

Heinrich, K. W 37

Hmdrlcks, 8. B 15

Hey. Max 11 31.32

Holxncr, Julius 12,21,22

Hutton, 0.0 22

SUlerophyllito, ferrian

Nockold's and Richey's formula . ..

WlnchelTs formula

Sidcrophyllltc-lepidomeUne series . .. .
Slderophyllltas, representative formulas

TctralHMlral groitp 12. 13. l4.2S.3l

Titanium, role of, in mleus 15

tetrahedral 32

Tr (octahedral micas, accommodation of trivalent cation .... 13=22

analyses not used tn study. 16-16. id

analyses used in study.. 16, 41-42

chemical composition 32-37

from pegmatite 26

geologic occurrence 32-37

layer Charge relations. 12-13

Mg-dtfldsat — 36

M. iV* ; rdatiou 22 = 2 1

Trbillclc-tetrnsiliclc series 12

Trivalent octahedral cations 12,15, 16^ 17,18.19.20, 2L 2.34

W Inched . A. N
Winch oil, 11

12. 3). 29. 30.31
12.30,31

KtmlU, W

Yoder, Hatton

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Giant Waves in
Lituya Bay
Alaska

By DON J. MILLER

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 3 5 4-C

A timely account of the nature and possible
causes of certain giant waves , with eyewitness
reports of their destructive capacity

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.

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CONTENTS

Pa**

Abstract 51

Introduction 51

Acknowledgments 53

Description and history of Lituya Bay 53

Geographic setting 53

Geologic setting 55

Exploration and settlement 56

Giant waves ..... 57

Evidence 57

Wave on July 9, 1958 67

Setting and sources of information 57

Eyewitness accounts 57

Account of Howard G. Ulrich ... 57

Account of William A. Swanson 58

Other observations on July 9... 59

Observations of the writer on July 10 59

Effects of the wavo ... 60

Destruction of vegetation ... 60

Other effects 62

Nature and cause of the wave .... 63

Comparable waves in other parts of the

world 67

Waves on October 27, 1936 67

Setting and sources of information 67

Eyewitness accounts 67

Account of Fred H. Fredrickson 67

Accounts of Bernard V. Allen and James
Huscroft ........ 68

Giant waves — Continued

Waves on October 27, 1936 — Continued

Effects of the waves

Nature and cause of the waves

Sudden draining of an ice-dammed body of

water

Fault displacement

Rockslide, avalanche, or landslide...

Submarine sliding... .........

Movement of a tidal glacier front...

Tsunami in the ocean. ... ...

Other possible causes....

Waves between 1854 and 1916

Eyewitness accounts

Other evidence

Dates. ....... ......

Effects of the waves ........

Nature and cause of the waves

Wave in 1853 or 1854

Eyewitness accounts

Other evidence

Date

Effects of the wave ....

Nature and cause of the wave..

Possibility of future waves ..... ...

Summary and conclusions.... ....

References cited

Index ......... ...

Pan

71
7 2

72
74
74
74
74

75
75

77
77
77
77
79
79
81
86

ILLUSTRATIONS

Plate 2. Map of Lituya Bay area ............. In pocket

Pag*

3. View of Lituya Bay, 1954 and August 1958 ... Facing 62

4. Gilbert Inlet and head of Lituya Bay, August 1958 Follows 62

5. A. South shore of Lituya Bay. B. Broken spruce tree at Harbor Point ................ Follows 62

6. A. View’ west on Cenotaph Island. B. North shore of Lituya Bay, August 1958 Facing 63

7. Spur southwest of Gilbert Inlet, August 1958 ............ Facing 72

8. Zones of denudation by giant waves and section of spruce tree from above 1936 trimlinc Follows 72

9. Destruction of forest by 1936 giant waves ......... Follows 72

10. Section of spruce tree from above 1853-54 trimline Facing 73

Figure 14. Map of part of southeastern Alaska, showing location and regional geographic setting of Lituya Bay 52

15. Map of Lituya Bay showing setting and effects of 1958 giant wave 58

16. Detailed map of head of Lituya Bay 61

17. Map of Lituya Bay showing setting and effects of 1936 giant waves 68

18. Map of Lituya Bay showing trimlines of one or more giant waves that occurred between 1854 and 1916 76

19. Map of Lituya Bay showing setting and effects of giant wave that occurred in 1853 or 1854....... 78

20. Map of head of Lituya Bay, showing areas susceptible to sliding 80

TABLE

Table 1. Data on localized giant waves generated by falling or sliding of solid masses 66

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GIANT WAVES IN LITUYA BAY, ALASKA

By Don J. Miller

ABSTRACT

Lltuya Bay, on the northeast shore of the Gulf of Alaska, Is
an Ice- scoured tidal inlet with a maximum depth of 720 feet and
a sill depth, at the narrow entrance, of only 33 feet. The north-
eastward-trending 8tem of the T-shaped bay, 7 miles long and
as much as 2 miles wide, transects the narrow coastal lowland
and foothills belt flanking the Falrweathcr Range of the St
Elias Mountains. The two arms at the head of the bay, Gilbert
and Crillon Inlets, are part of a great trench along the Fair-
weather fault Gentle slopes border the outer pnrt of the bay,
but the walls of the Inner, flordlike part rise steeply to altitudes
of 2,200 feet to more than 0,000 feet

Until recently, little notice was taken of the giant waves that
have rushed out from the head of Lltuya Bay, leaving sharp
trlmllnes to mark the upper limit of total or near total de-
struction of the forest along the shores. The dates of occur-
rence of 4 known and 1 Inferred giant waves, and the maximum
altitudes of their trimlines are as follows: July 9, 1958 — 1,720
feet ; October 27, 1936 — 190 feet ; 1899 ( ?) — about 200 feet ; about
1874—80 feet; and 1853 or 1854—395 feet.

In 1958 about 40 million cubic yards of rock, loosened either
by displacement on the Falrweather fault or by the accompany-
ing shaking, plunged Into Gilbert Inlet from a maximum alti-
tude of about 3,000 feet on the steep northeast wall. This
rockslide caused water to surge over the opposite wall of the
Inlet to a maximum altitude of 1,740 feet, and generated a
gravity wave that moved out the bay to the mouth at a speed
probably between 97 and 130 miles per hour. Two of three fish-
ing boats In the outer part of the bay were sunk, and two per-
sons were killed. The Interpretation that water was primarily
responsible for destruction of the forest over a total area of 4
square miles, extending to a maximum altitude of 1,720 feet
and as much as 3,600 feet in from the blgh-tide shoreline, Is
supported by eyewitness accounts of the survivors, by the
writer’s field investigation, and by R. L. Wiegel’s study of a
model of Lltuya Bny and his calculations from existing theory
and data on wave hydraulics.

The giant waves In 1936 were generated in Crillon Inlet
They were described by eyewitnesses at a point about midway
along the bay as 3 waves of Increasing height In close succes-
sion and traveling about 22 miles per hour. Of the possible
causes considered here, movement of a tidal glacier front or sub-
marine sliding seems most likely but can be neither disproved
nor conclusively supported from the Information at band.

The configuration of trlmllnes formed by giant waves In late
1853 or early 1854 (dated by tree ring count) and about 1874,
suggests sliding from the south wall of Lltuya Bay at Mudslide
Creek as a likely cause. A slide, fault displacement, or some
other disturbance In Crillon Inlet may have caused another

giant wave during one of the great earthquakes In September
1899.

The frequent occurrence of giant waves In Lltuya Bay, as
compared to other similar bays, Is attributed to the combined
effect of recently glaciated steep slopes, highly fractured rocks
and deep water in an active fault zone, heavy ralnfalt, and fre-
quent freezing and thawing. These waves are likely to occur
again, and should be taken Into account In any future use of
Lltuya Bay. Other giant waves have been caused by sliding
of part of a mountain into Shlmabara Bay in Japan ; repeatedly
by falling or sliding of rock masses Into Ix>en Lake, Tafjord, and
Langfjord In Norway ; by avalanching of a hanging glacier Into
Disenchantment Bay in Alaska; and repeatedly by landslides
Into Franklin D. Roosevelt Lake in Washington.

INTRODUCTION

Lituya Bay is an ice-scoured, nearly landlocked tidal
inlet on the northeast shore of the Gulf of Alaska (fig.
14). Most descriptions of Lituya Bay, including that
of its discoverer La Perouse (1798), have dwelt at
length on the hazards of the strong tidal current in the
narrow entrance, but until recently, little notice was
taken of an even more remarkable and potentially more
dangerous hydraulic oddity of the bay — its propensity
for developing enormous waves. At least four times
during a little more than a century giant waves have
rushed out from the head of the bay, destroying the
forest on the shores and leaving trimlines similar to
those formed by glaciers. The latest and largest of
these waves washed out trees to a maximum altitude of
1,720 feet, more than 8 times the maximum recorded
height of a tsunami breaking on an ocean shore (Leet,
1948, p. 179).

The writer became interested in the giant waves while
studying the Tertiary rocks in Lituya Bay and adjoin-
ing area in 1952 and 1953, as a part of the U.S. Geolog-
ical Survey’s program of petroleum investigations in
the Gulf of Alaska region. The two trimlines then
recognized were mapped and their approximate ages
determined, inquiries were made of residents and
former residents of the region, and a search was begin
for references to the origin of the trimlines in Lituya
Bay and to comparable features in other places. In a

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Piouhb 14. — Map of part of southeastern Alaska, showing location and regional geographic setting of Lltuja Bay.

paper read at geological meetings in Seattle, Wash,
and Anchorage, Alaska, and published in abstract
(Miller, 1054) the trimlines in Lituya Bay were attrib-
uted to cataclysmic floods or waves of water moving out
from the head of the bay at high velocity. The infor-
mation then available did not give conclusive support

to any of several possible mechanisms that were sug-
gested for setting the water in motion.

The investigation of the cause of the floods or waves
was laid aside, except for correspondence and the ac-
cumulation of additional references, until the spring of
1958 when assignment to a field mapping project based

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GIANT WAVES IN LIT0YA BAT, ALASKA

in Juneau afforded opportunities to resume the search
for local sources of information. On July 9 much
new information was provided in a dramatic and wholly
unexpected way when a major earthquake centering
near Lituya Bay was followed almost immediately by
a wave that denuded an area of about 4 square miles
in Lituya Bay, destroyed 2 of 3 fishing boats anchored
in the bay, and killed 2 people. The problem of the
cause of the waves, until then mainly of scientific inter-
est, became overnight a matter of general public
interest.

The earthquake late in the evening of July 9 1 was
strongly felt on the U.S. Geological Survey power
barge, Stephen R. Capps, at anchor in Glacier Bay
about 60 miles east of Lituya Bay. Rocks fell into the
water from steep cliffs nearby, causing small waves
that broke with a height of not more than 2 or 3 feet
on the shores; no large waves were seen, however.
Upon learning by radio on the following morning of
the destruction in Lituya Bay, the writer chartered a
small pontoon-equipped airplane, and spent about 1%
hours flying over the bay at low altitude. Observation
and photography were hampered by low ceiling, rain,
and fog, and no landings could be made in the debris-
choked bay. Early in August, when the power barge
was anchored in Dixon Harbor about 30 miles southeast
of Lituya Bay, a helicopter was used for 1^ days of
ground and aerial observations and photography of
the bay. In late August and early September the
writer again photographed and examined Lituya Bay
on several flights with fixed-wing aircraft, and camped
for 3 days in the bay.

On August 29, 1958, a photographic mission of the
U.S. Coast and Geodetic Survey photographed tlie en-
tire Lituya Bay area with a 9-lens aerial camera, and
also made single-lens vertical photographs of the
entrance.

ACKNOWLEDGMENTS

D. L. Rossman, George Plafker, R. C. Ellis, E. A.
Hainze, and Todd Nelson all assisted in the field at
times during the 1952-53 seasons. R. L Velikanje,
C. L. Sainsbury, R. E. Marsh, Mrs. Caroline Jensen,
and L. H. Bayers in the Juneau office of the U.S. Geo-
logical Survey canvassed potential sources of informa-
tion by interview and letter. R. F. Taylor, forester in
charge of the Alaska Forest Research Center in Juneau,
gave advice on tree ring studies made in the field in 1953
and arranged for preparation of tree sections; R. M.
Godman of the same organization counted and inter-
preted the growth rings.

1 Morning of July 10. Orernwich clrll time : Pacific standard time
(120* W. meridian time) te need throughout this report.

A. J. Mitchell, superintendent of the Sitka and
Glacier Bay National Monuments, in 1958 aided in
gathering local information on the waves, provided
logistic support and encouragement to the investiga-
tion, and accompanied the writer on one flight to Lituya
Bay. J. P. McKee, E. L. Henrickson, V. L Mann and
Edward Berdusco of the Fremont Mining Co. provided
a valuable record of conditions in Lituya Bay immedi-
ately preceding the 1958 wave and also called attention
to evidence for movement along the Fairweather fault
near Lituya Bay. Part of the logistic support for the
1958 field investigation was provided by the Geological
Survey’s southeastern Alaska project barge and heli-
copter and by Seventeenth Coast Guard District air-
plane. Special thanks are due to pilot Kenneth Loken
of Juneau for making it possible to inspect Lituya Bay
shortly after the 1958 wave, despite adverse weather.

Don Tocher of the University of California Seismo-
graphic Station joined the writer in making a field
investigation of the effects of the 1958 earthquake, and
contributed valuable suggestions on the interpretation
of the giant waves and on the preparation of this
report. R. L. Wiegel of the Institute of Engineering
Research, University of California, made a model study
of the 1958 wave and generously contributed the result-
ing observations for quotation in this report. A. R.
Tagg of the U.S. Geological Survey made the photo-
grammetric measurements of trimline altitudes. The
writer is indebted to F. H. Fredrickson, Mr. and Mrs.
W. A. Swanson, and H. G. Ulrich for their cooperation
in providing eyewitness accounts of the waves. Photo-
graphs of Lituya Bay and information on the waves
were furnished by W. O. Field, Jr., of the American
Geographical Society, Bradford Washburn, of the
Museum of Science, Boston, Mass., and Tom Smith,
Trevor Davis and Robert De Armond of Juneau.
Finally, many other persons not specifically mentioned
here have contributed suggest ions as to the cause of the
waves, sources of information and methods of attacking
the problem, and helpful criticism of the manuscript.

DESCRIPTION AND HISTORY OF LITUYA BAY
GEOGBAPHIC SETTING

Lituya Bay is a T-shaped inlet that cuts through the
coastal lowland and foothills belt flanking the Fair-
weather Range of the St. Elias Mountains, on the south
coast of Alaska ( fig. 14, pi. 2) .

The entrance of the bay, at lat 58*36'45" N., long
137*39'40" W., is 122 miles west of Juneau and 99 miles
southeast of Yakutat. The main part of the bay, cor-
responding to the stem of the letter T, is 7 miles long
and ranges from three-fourtlis of a mile to 2 miles in
width except at the entrance, which has a width of only

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

1,000 feet at low tide. Cenotaph Island divides the
central part of the bay into two channels, two-fifths and
four-fifths of a mile in width. Gilbert and Crillon
Inlets extend northwestward and southeastward, re-
spectively, from the head of the bay to form the upper
part of the T, which in 1958 was about 3 miles long.
The name “Lituya,” according to Emmons (1911, p.
294), is a compound word in the Tlingit language
meaning “the lake within the point,” in reference to the
nearly landlocked nature of the bay.

Lituya Bay was aptly described by Dali (1883, p.
20-4) as “a Yosemite Valley, retaining its glaciers and
with its floor submerged six or eight hundred feet.”
The bay fills and slightly overflows a depression only
recently occupied by a piedmont glacier lobe and its
tributary valley glaciers, of which the present Lituya,
Cascade, and North Crillon Glaciers are remnants
(pi. 2). The maximum stand of the Lituya Glacier
system is clearly recorded by the arcuate end moraine
that forms La Chaussee Spit and is continuous with
lateral moraines and trimlines rising gradually to an
average altitude of about 1,800 feet at the head of the
bay (pi. 3 A.). The Solomon Railroad (pi. 2), a part
of the end and lateral moraine north of the bay, rises
abruptly like a railroad embankment to a sharp, even
crest standing as much as 600 feet above the adjoining
lowlands.

Lituya and North Crillon Glaciers, each about 12
miles long and 1 mile wide, originate in ice fields at
altitudes of 4,000 feet and higher near the crest of the
Fairweather Range. Both glaciers flow soutliwestward
down the flank of the Fairweather Range and make
nearly right-angle turns into the northwestward-trend-
ing trench between this range and the foothills. In
the summer of 1958 about 1,600 feet or one-tliird of
tho total width of the front of North Crillon Glacier
was tidal at the head of Crillon Inlet. The surface of
this glacier near the front was mostly debris covered
and relatively smooth. .Just prior to the earthquake
and wave in 1958 about 3,000 feet of the front of Lituya
Glacier was tidal. The surface of this glacier near
the front was rough, with little debris cover except
along the southwest margin and at a narrow medial
moraine near the northeast margin. At the end of
August 1958 almost the entire front of Lituya Glacier
was tidal, and deeply crevassed. Cascade Glacier is
about 4 miles long and very steep. Its terminus in
recent years has been low and largely debris covered.
At tho end of August 1958 only a small part of the
glacier terminus reached the high-tide shoreline at the
head of Lituya Bay.

The shores around the outer part of Lituya Bay are
mainly bouldery beaches, the adjoining land rising

away from the beach at rates ranging from 100 feet in
a horizontal distance of 6,000 feet, near Fish Lake, to
540 feet in a horizontal distance of 1,200 feet at The
Paps (pi. 2). Around the head of the bay the walls
are steep and fiordlike, rising to altitudes between 2,200
and 3,400 feet in the foothills immediately to the north
and south, and to more than 6,000 feet in the Fair-
weather Range less than 2 miles from the shore of
Crillon Inlet. The submarine contours, based on
soundings made in 1926 and 1940 (U.S. Coast and
Geodetic Survey, 1942), show a pronounced U-shaped
trench with steep walls and a broad, flat floor sloping
gently downward from the head of the bay to a maxi-
mum depth of 720 feet just south of Cenotaph Island,
and rising again toward the outer part of the bay.
The minimum depth in the entrance is 33 feet at mean
lower low water ; hence the bay has a closure of at least
687 feet. The tide in the bay is diurnal, with a mean
range of 7 feet and a maximum range of about 15 feet
(U.S. Coast and Geodetic Survey, 1957). The tidal
current in the narrow entrance attains a velocity of 12
knots (U.S. Coast and Geodetic Survey, 1952), or
about 13.8 statute miles per hour.

Weather records for the 2 stations nearest Lituya
Bay, at Cape Spencer 47 miles to the southeast and
at Yakutat 99 miles to the northwest (U.S. Weather
Bureau, 1958), indicate that the total annual precipita-
tion ranges from 111 to 134 inches and the mean annual
temperature ranges from 39° to 41° F. in this coastal
area. Because of the heavy precipitation and mild cli-
mate at low altitude, the lower slopes ( from the liigh-
tide line to an altitude of 1,700 to 2,000 feet) where
not overly steep or poorly drained, normally are covered
by a dense growth of trees and brush. Reforestation
of land newly exposed by the retreat of glaciers or the
sea, or, as in Lituya Bay, denuded by waves, under
present climatic conditions at this latitude takes place
in the following succession: dense stands of alder
(Alnxis) and willow (Salix) grow within a few years,
but are soon exceeded in height by cottonwood (Pop-
vlm trichocarpa) ; Sitka spruce ( Picea sitchensis) next
dominates but gradually becomes mixed with hemlock
( Tmga krterophylla and T. mertemiana) ; and finally
Alaska cedar ( Cliamaecyparu nootkatemis) appears.
At the time of the 1958 wave, forests of five distinct
ages were growing on or near the shores of Lituya Bay.
These zones, as identified on plate 8 A, are: mixed alder,
willow, cottonwood, and spruce with a known maximum
age of 22 years (shore to k ) ; 2 bands of mixed spruce
and cottonwood with maximum ages of about 84 years
(h-j) and of 105 years (j-h ) ; mixed spruce and hem-
lock with an estimated age of 400 years or more (k-~m ) ;

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GIANT WAVES IN LITUYA BAY, ALASKA

and mixed spruce, hemlock, and cedar probably more
than 1,000 years old (above to).

GEOLOGIC SETTING

Lituya Bay lies near the southeast end of and tran-
sects a geologic province in which sedimentary rocks
of Tertiary age are exposed or inferred to underlie low-
land areas (Gryc, Miller, and Payne, 1051, p. 159-162).
The two arms at the head of Lituya Bay are part of a
great trench that extends for many miles to the north-
west and southeast along the southwest front of the
Fairweather Range and the southern part of the St.
Elias Mountains (fig. 14). Mertie (1931, p. 123) first
recognized this trench as the topographic expression
of a major fault, named more recently the Fairweather
fault (Miller, 1953). Field investigations by the
writer and by D. L. Rossman (written communication,
1957) indicate that the Fairweather fault from the
vicinity of Lituya Bay southeast to Palma Bay is verti-
cal or dips steeply to the northeast. Along this fault
the crystalline rocks exposed on the northeast side are
inferred to have moved up relative to less altered and
in part, younger rocks exposed in the lowland and foot-
hills belt on the southwest, side. St. Amand (1957, p.
1357-1359) suggested, however, that the fault is of
lateral or oblique habit, and cited as evidence some of
the effects of the 1899 earthquakes in Yakutat Bay.

Instrumental and field observations point to move-
ment along the Fairweather fault as the cause of the
earthquake immediately preceding the 1958 wave in
Lituya Bay. Tocher and Miller (1959) studied the
surface breakage where the trace of the fault is exposed
near Crillon Lake, 6 to 10 miles southeast of Lituya
Bay. At one point the southwest side moved north-
westward at least 21 V£ feet and up 3% feet. Slides and
other evidence of strong shaking observed elsewhere
along known or inferred trace of the Fairweather fault
from Palma Bay to the latitude of Nunatab Fiord near
Yakutat Bay, indicated tearing along the fault prob-
ably for 115 miles or more. The instrumental epicenter
of the earthquake, as determined by the U.S. Coast and
Geodetic Survey (Brazee and Jordan, 1958, p. 36), is
lat 58.6° N., long 137.1°W., a point in the Fairweather
Range about 7% miles east of the surface trace of the
Fairweather fault and 13 miles southeast of the head of
Lituya Bay. A later determination from a larger num-
ber of stations (William Stauder, written communica-
tion, paper given at Tucson meeting of Geol. Soc.
America; oral communication, Apr. 29, 1959) places
the epicenter farther southeast but nearer the assumed
surface trace of the Fairweather fault.

Bedrock is exposed or lies beneath only a thin veneer
of soil, glacial drift, or talus at water level around most
532778—60 2

of Cenotaph Island and from a point 4% miles inside
the entrance on the south shore around the head of Lit-
uya Bay to a point 5% miles inside the entrance on the
north shore. The rocks are largely hard schist on the
northeast shore of Gilbert and Crillon Inlets. Diorite
and slightly metamorphosed volcanic rocks, slate, and
graywacke are exposed on the southwest shore of Gil-
bert Inlet and the adjoining north shore of the bay, on
the southwest shore of Crillon Inlet, and on the south
shore of the bay as far as the mouth of Coal Creek.
Bedded sedimentary and volcanic rocks of Tertiary age
are exposed on Cenotaph Island and on the south shore
west of Coal Creek. Around most of the outer part of
the bay boulder till is exposed at the surface or lies
under a thin soil.

Field observations in 1952 and 1953 indicated that the
forest inside the moraine enclosing the outer part of
Lituya Bay, but above the highest trimline, is distinctly
younger than the forest, growing along the coast outside
of the moraine. Although no tree ring counts were
made, the writer noticed that there was much less dead-
fall in the forest inside the moraine, and that the spruce
and hemlock trees were smaller inside the moraine.
Moreover, Alaska cedar trees as much as 3 feet in di-
ameter were found growing up to the outer edge of the
moraine, but not even small cedars were seen inside the
moraine. This evidence of a post- Wisconsin advance
of ice to the mouth of Lituya Bay is now corroborated
by evidence newly exposed by the 1958 giant wave. An
ice-sheared stump, rooted in a humus-rich soil just be-
low the surficial till on the south shore near the entrance
of the bay (fig. 15, loc. A), has a radiocarbon age of
6,060 ± 200 years B. P. (Meyer Rubin, written com-
munication, U.S. Geological Survey lab. no W-800 re-
port, May 26, 1959) .

The evidence indicates that ice stood at or near the
mouth of Lituya Bay within the time required for
growth of a climax forest in tliis region, possibly less
than 1,000 years ago. However, the ice fronts were
farther back when the La Perouse expedition visited
Lituya Bay in 1786 than at the present time. The map
made under the direction of La Perouse ( 1798, opposite
p. 146; also Klotz, 1899) shows two tidal glaciers at the
head of each inlet, which indicates that the ice fronts
had retreated to positions beyond the points where the
Lituya and North Crillon Glaciers enter the trench at
the head of the bay. The combined length of Gilbert
and Crillon Inlets then was about 9 miles. By 1894
both Lituya and North Crillon Glaciers had readvanced
nearly to their present positions (Klotz, 1899). Prior
to the 1958 wave low deltas of gravel had built out into
Gilbert Inlet at the southwest and northeast margins
of the Lituya Glacier front, and into Crillon Inlet

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

across about two-thirds of the width of the North
Crillon Glacier front (fig. 15). These deltas formed
after 1894, and they may be, or may have been, in part
underlain by ice projecting from the glacier fronts be-
low sea level.

EXPLORATION AND SETTLEMENT

Available records of the exploration and settlement
of the northeastern Gulf of Alaska coast afford only a
sketchy history of Lituya Bay beginning in 1786.
Little information has been found for the period 1788-
1874, during which time at least one destructive wave
occurred and Indian settlements in the bay were aban-
doned, perhaps as a direct result of a wave. Records
of visits to or settlement in the bay after 1874, including
the accounts of geographic surveys and scientific inves-
tigations, contain few references to the occurrence of
large waves.

The French explorer La Perouse (1798, p. 115-169)
is generally credited with the discovery of Lituya Bay,
which he named Port des Francois. In the course of a
projected trip around the world La Perouse took his
ships La Boussole and V Astrolabe into Lituya Bay on
July 2, 1786. During a stay of nearly a month the ex-
pedition mapped Lituya Bay on a scale of 1 : 50,000,
traded with the Indians then living in and near the bay,
and recorded observations on the native culture and the
plant and animal life in the vicinity. Twenty-one men
were drowned when three small boats engaged in a sur-
vey of the entrance were swept into the tidal bore and
two were wrecked. In July 1788 Ismailof and Bech-
arof entered Lituya Bay on the ship Three Saint* to
claim the land for Russia and to induce the natives to
accept Russian rule (Shelikof, 1812, p. 108-112). The
lack of any reference to waves within the bay in either
of these early accounts, together with the mention of
trees and native dwellings near the shore, are indirect
evidence that no giant waves had occurred in Lituya
Bay for some time prior to 1788.

For the remainder of the period of Russian rule and
the early years of American rule, until 1874, the litera-
ture examined contains only brief mention of explora-
tion in Lituya Bay: in connection with an expedition
of the Russian ship Orel to obtain sea otter skins in
1796 (Bancroft, 1886, p. 856-357) ; the reported dis-
covery and mining of gold placer deposits on the
beaches in the vicinity of Lituya Bay by the Rus-
sian censuses of the Tlingit tribe give the population
American whaling ships (Dali, 1883, p. 202). Rus-
sian censuses of the Tlingit tribe give the population
of the Lituya clan or settlement as 200 in 1835, and 590
in 1861 (Petroff, 1884, p. 96, 99). Perhaps only a

small part of the clan lived in Lituya Bay, for the
French and Russian expeditions in 1786 and 1788
reported that the main village was northwest of the
bay.

A U.S. Coast and Geodetic Survey party entered
Lituya Bay in 1874 to make geodetic observations and
to revise the La Perouse chart of the outer part of the
bay (Dali, 1878, p. 158; 1833). No natives were then
living in the bay and the village on the south shore
seemed to have been abandoned for a long time. In
1894 a topographic map of the region adjoining Lituya
Bay was made by a Canadian party of the International
Boundary Survey (U.S. Congress, 1904; International
Boundary Commission, 1952, p. 254) ; observations on
the glaciers at the head of the bay were later published
by Klotz (1899, p. 524-526, maps). The bay was vis-
ited by field parties of the U.S. Geological Survey for
3 days in 1906 (Wright, F. E., and Wright, C. W. in
Reid, 1908, p. 53; in Buddington and Chapin, 1929,
p. 269-270) and in 1917 (Mertie, 1931), and for 5 days
in 1943 (Kennedy and Walton, 1946, p. 67-72). Sur-
veys of the bay were resumed by the U.S. Coast and
Geodetic Survey in 1926 and 1940, resulting in the cur-
rent navigation chart on a scale of 1 : 20,000 (U.S. Coast
and Geodetic Survey, 1942). In 1926, and during part
of each summer from 1930 to 1934, expeditions engaged
in mountain climbing or geographical and geological
exploration were based in or near Lituya Bay (Carpe,
1931; Washburn, 1935, 1936; Goldthwait, 1936). Ex-
cept for the brief mention of “evidence of flooding or
washing to a height of at least 10 feet,” which Dali
(1883, p. 203) attributed to damming of the entrance
by ice during the winter, none of the reports on the
expeditions just described contain any reference to the
giant waves in Lituya Bay.

Placer mining of the gold in the sands along the
ocean beach adjacent to the mouth of Lituya Bay was
begun by the Americans in 1890 (Boursin, 1893, p.
230) and continued intermittently at least until 1917
(Mertie, 1931, p. 133). Since Lituya Bay served as a
port for this operation, during this period it was prob-
ably occupied or at least visited frequently. One man,
James Huscroft, lived on Cenotaph Island in Lituya
Bay almost continuously from 1917 to about 1940.
Huscroft and another man were on the island, and two
men were in a boat nearby, at the time of the 1936
waves. Their eyewitness accounts, the observations of
Tom Smith and others who visited the bay only a few
days later, and the observations of J. P. Williams
nearly a year later, led to the earliest known pub-
lished references to the unusual “waves or floods” of
water in Lituya Bay (Alaska Daily Press, 1936;
Williams, 1938).

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GIANT WAVES IN LITUYA BAY, ALASKA

Lituya Bay was incorporated in the Glacier Bay
National Monument when the boundary was extended
in 1939 to include the coastal area from Cape Spencer
north to Cape Fairweather (fig. 14). No one has lived
permanently either in or near the bay since Huscroft
died, but in recent years the bay has come into increas-
ing use as an overnight anchorage and refuge in bad
weather for the trolling boats of the fishermen who ply
the adjoining waters of the Gulf of Alaska during the
summer and early fall.

THE GIANT WAVES
EVIDENCE

Two kinds of evidence testify to the occurrence of
at least four giant waves in Lituya Bay: (a) direct
observation of the waves, including the published, writ-
ten, or oral accounts of eyewitnesses and possibly tidal
gage records from elsewhere in the Gulf of Alaska;
(b) effects that remain for later observation, mainly
the destruction and transportation of vegetation, but
also the erosion and transportation of unconsolidated
deposits, destruction of marine life, and the destruction
of works of man. The wave on July 9, 1958, and the
waves on October 27, 1936, are documented beyond any
doubt by both types of evidence. At least 1 and pos-
sibly 2 waves between 1854 and 1916 are indicated by
trimlines shown on photographs taken from 1894 to
1929. These trimlines were largely destroyed by the
1936 wave, and were entirely gone after the 1958 wave.
An oral report placing one of these waves in 1899 has
not been substantiated. A wave in 1853 or 1854 is
recorded in a trimline and a band of even-aged trees
that was examined and mapped on the ground and
dated by tree ring counts in 1952 and 1953. Possible
references to the 1853-54 wave in Indian legends have
not been confirmed.

WAVE ON JULY 9, 1958
SETTING AND SOURCES OF INFORMATION

Three trolling boats, each about 40 feet long and
with two persons aboard, were anchored in the outer
part of Lituya Bay at the time of the wave on July 9
(fig. 15; pi. 32?). The Edrie rode out the wave inside
the bay; the Badger was carried across La Chaussee
Spit and wrecked on the outside; the Sunmore , under
way near the entrance, was swamped by the wave and
went down with her occupants. The wave reportedly
was first sighted within 3 minutes after the earth-
quake was first felt, or, using the instrumentally deter-
mined origin time for the earthquake of 06T5“51*G.c.t,,
July 10 (Tocher and Miller, 1959), between 10:16 and
10: 19 p. m. on July 9, local time. This is about sunset

at this latitude and time of year; the weather was
clear, with high scattered clouds, and the head of the
bay was clearly visible from boat level at the outer
part of the bay. The tide was ebbing and at about plus
5 feet (U. S. Coast and Geodetic Survey, 1957) or less
than a foot above mean tide stage in the bay. The fol-
lowing eyewitness accounts are abstracted from articles
published in newspapers and a magazine (Daily Alaska
Empire, 1958a; Ulrich, 1958; Alaska Sportsman, 1958),
from a personal interview with W. A. Swanson (oral
communication, July 16, 1958) and correspondence
with II. G. Ulrich (written communication, Oct. 24,
1958).

EYEWITNESS ACCOUNTS
ACCOUNT OF HOWARD O. ULRICH

Mr. Ulrich and his 7-year-old son, on the Edrie ,
entered Lituya Bay about 8:00 p.m. and anchored in
about 5 fathoms of water in a small cove on the south
shore (fig. 15). Ulrich was awakened by the violent
rocking of the boat, noted the time, and went on deck
to watch the effects of the earthquake — described as
violent shaking and heaving, followed by avalanching —
in the mountains at the head of the bay. An estimated
2Vfc minutes after the earthquake was first felt a deafen-
ing crash was heard at the head of the bay. According
to Ulrich,

The wave definitely started iu Gilbert Inlet, Just before the
end of the quake. It was not a wnve at first It was like an
explosion, or a glacier sluff. The wave came out of the lower
part, and looked like the smallest part of the whole thing. The
wave did not go up 1,800 feet, the water splashed there.

Ulrich continued to watch the progress of the wave
until it reached his boat about 2% to 3 minutes after it
was first sighted. Being unable to get the anchor loose,
he let out all of the chain (about 40 fathoms) and
started the engine. Midway between the head of the
bay and Cenotaph Island the wave appeared to be a
straight wall of water possibly 100 feet high, extending
from shore to shore. The wave was breaking as it came
around the north side of the island, but on the south
side it had a smooth, even crest. As it approached the
Edrie the wave front appeared very steep, and 50 to
75 feet high. No lowering or other disturbance of the
water around the boat, other than vibration due to the
earthquake, was noticed before the wave arrived. The
anchor chain snapped as the boat rose with the wave.
The boat was carried toward and probably over the
south shore, and then, in the backwash, toward the
center of the bay. The wave crest seemed to be only 25
to 50 feet wide, and the back slope less steep than the
front.

After the giant wave passed the water surface
returned to about normal level, but was very turbulent,

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

with much sloshing back and forth from shore to shore
and with steep, sharp waves up to 20 feet high. These
waves, however, did not show any definite movement
either toward the head or the mouth of tho bay. After
25 to 30 minutes the bay became calm, although float-
ing logs covered the water near the shores and were
moving out toward the center and the entrance. After
the first, giant wave passed Ulrich managed to keep the
boat under control, and went out the entrance at 1 1 :00
p.m. on what seemed to be a normal ebb flow.

ACOOUNT or WILLIAM A. 8 WAN 80 N

Mr. and Mrs. Swanson on the Badger entered Lituya
Bay about. 9 :00 p.m., first going in as far as Cenotaph
Island and then returning to Anchorage Cove on the
north shore near the entrance, to anchor in about 4
fathoms of water near the Sunmore (fig. 15). Mr.
Swanson was wakened by violent vibration of the boat,

and noted the time on the clock in the pilot house. A
little more than a minute after the shaking was first
felt, but probably before the end of the earthquake,
Swanson looked toward the head of the bay, past the
north end of Cenotaph Island and saw what he thought
to be the Lituya Glacier, which had “risen in the air
and moved forward so it was in sight. * * * It seemed
to be solid, but was jumping and shaking * * * Big
cakes of ice were falling off the face of it and down into
tho water.” After a little while “tho glacier dropped
back out. of sight and there was a big wall of water
going over the point” (the spur southwest of Gilbert
Inlet). Swanson next noticed the wave climb up on
the south shore near Mudslide Creek. As the wave
passed Cenotaph Island it seemed to be about 50 feet
high near the center of the bay and to slope up toward
the sides. It passed the island about 2% minutes after
it was first sighted, and reached the Badger about 1V&

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GIANT WAVES IN LITUYA BAY, ALASKA

minutes later. No lowering or other disturbance of
the water around the boat was noticed before the wave
arrived.

The Badger, still at anchor, was lifted up by the wave
and carried across La Chaussee Spit, riding stem first
just below the crest of the wave, like a surfboard.
Swanson looked down on the trees growing on the spit,
and believes that he was about 2 boat lengths (more
than 80 feet) above their tops. The wave crest broke
just outside the spit and the boat hit bottom and foun-
dered some distance from the shore. Looking back 8 to 4
minutes after the boat hit bottom Swanson saw water
pouring over the spit, carrying logs and other debris.
He does not know whether this was a continuation
of the wave that carried the boat over the spit or a
second wave. Mr. and Mrs. Swanson abandoned their
boat in a small skiff, and were picked up by another
fishing boat about 2 horn’s later.

OTHER OBSERVATIONS ON JULY 9

So far as is known to the writer, no other persons
were near enough to Lituya Bay to see the wave, and
no photographs were taken. A party of eight moun-
tain climbers was camped in tents on the shore of
Anchorage Cove, at the base of La Chaussee Spit, until
about 8:00 p.m. on July 9, when they left in an am-
phibious airplane only a little more than 2 hours before
the wave washed over their campsite. They did not
notice any unusual noises or disturbance of the water
in the bay, nor any foreshocks of the earthquake up to
the time they left (Paddy Sherman, written communi-
cation, Oct. 20, 1958). At lenst one foreshock of the
earthquake was felt on the morning of July 9 on boats
between Lituya Bay and Cape Spencer (William
Swanson, oral communication, July 16, 1958), and on
land as far away as Juneau (E. L. Keithalui, written
communication, Apr. 3, 1959) .

Minor anomalous waves which may have been a
direct result of the giant wave in Lituya Bay were
recorded on the U.S. Coast and Geodetic Survey tide
gage at Sitka, on Sitka Sound, 137 miles southeast of
the entrance of Lituya Bay. The waves began at 11 : 25
p.m., July 9, with a height of about 0.1 foot, and con-
tinued for many hours. The maximum wave height of
about 0.3 foot occurred at about 2:40 a.m., July 10
(H. A. Karo, written communication, May 20, 1959).
The first wave arrived at Sitka approximately 65 min-
utes after the giant wave washed over the entrance of
Lituya Bay into the sea; the indicated average speed of
about 126 miles per hour, assuming a nearly straight
line route of travel through Salisbury Sound and the
narrow waterways east of Kruzof Island, is comparable
to the observed velocities of tsunamis. It is possible

that the waves at Sitka were generated by fault dis-
placement or some effect of the resulting earthquake
at a point of origin other than Lituya Bay. Such
waves were observed within a few minutes after the
earthquake at Dixon Harbor 45 miles southeast of
Lituya Bay (William Brammer, oral communication,
July 10, 1958) and at Yakutat 99 miles northwest
(Brazee and Jordan, 1958, p. 38), as well as on inland
waters in Glacier Bay 60 miles to the east (observed by
the writer) .

OBSERVATIONS OF THE WRITER ON JULY 10

About 1% hours were spent over Lituya Bay in a
small airplane on the morning of July 10, beginning
about 12 hours after the wave had passed through the
bay. Observations made at tills time on the more
ephemeral phenomena associated with the earthquake
and wave are described separately here because they
bear particularly on the interpretation of the eyewitness
accounts and on the nature and sequence of events in
Lituya Bay on the day of the wave. The observations
wore recorded on a map, and by means of notes, still
photographs, and movies. Kenneth Loken, pilot of the
airplane, had flown over Lituya Bay on July 7 and was
able to make an on-the-spot comparison of conditions
before and after the July 9 earthquake and wave.

On the morning of July 10 Gilbert and Crillon Inlets
and the upper part of the main trunk of Lituya Bay for
a distance of 2% miles from the head were covered by
an almost, solid sheet of floating ice blocks. Many of
the blocks were much larger than are normally seen in
the bay, with exposed dimensions, us estimated from
oblique photographs, of as much as 50 by 100 feet.
Nearly all of the larger blocks had flat upper surfaces
and were heavily debris laden, and many had scattered,
loose, large rounded boulders on their exposed surfaces.
Only scattered small pieces of ice, in normal abundance,
were floating in the outer part of the bay beyond Ceno-
taph Island. Only on the northeast shore of Gilbert
and Crillon Inlets and on the large delta at the south-
east end of Crillon Inlet was any great amount of ice
left stranded on the beach above the high-tide line. The
absence of stranded ice blocks on the spur southwest of
Gilbert Inlet is especially significant as an indication
that the glaciers were not involved in the generation of
the initial splash or surge of water at the head of the
bay.

The front of Lituya Glacier on July 10 was a nearly
straight, vertical wall almost normal to the trend of the
valley. Comparison of oblique photographs taken by
the writer on July 10 and by Edward Berdusco on July
7 indicate that during the earthquake and wave as much
as 1,300 feet of ice had been sheared off of the glacier

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

front, but that the southwest margin had changed very
little (fig. 16). The delta on the northeast side of Gil-
bert Inlet had completely disappeared, and the delta on
the southwest side was much smaller. It is possible
that ice projected beyond the subaerial part of the
glacier front, beneath the inner parts of these deltas
and that these projections are the source of the large
debris-laden blocks of ice floating in the bay on July 10.
The glacier surface for several hundred feet from the
front was severely crevassed, probably more so than
normal ; beyond this terminal zone, however, the glacier
as far up as the partly subglacial lake near the sharp
bend in Lituya Glacier (pi. 2) showed no evidence of
any unusual movement. The level of the lake, accord-
ing to Loken, may have lowered as much as 100 feet
since he had seen it 2 days earlier.

The front of North Crillon Glacier and the adjoining
large delta showed no indications of any significant for-
ward movement of the glacier or of any other disturb-
ance except effects of washing by the component of the
wave that had moved southeastward into Crillon Inlet.
The front and lower part of Cascade Glacier similarly
showed no effects other than of washing by the wave,
which had exposed a narrow tongue of nearly clear ice
extending to the shoreline.

The most striking change at the head of Lituya Bay,
aside from the new trimline, was the fresh scar on the
northeast wall of Gilbert. Inlet, marking the recent posi-
tion of a large mass of rock that had plunged down the
steep slope into the water (fig. 16; pi. '1/1). Loose rock
debris on the fresh scar was still moving at some places,
and small masses of rock still were falling from the
nearly vertical rock cliffs at the head of tho scar. The
fresh scar is not present on an oblique photograph
taken by Edward llerdusco on July 7. This evidence,
as well as Ulrich’s account, indicates almost certainly
that tho rockslide was triggered by the earthquake on
July 9. The rockslide is described in greater detail on
page 65.

Floating logs and other vegetation formed a nearly
continuous raft as much as 1,200 feet wide along the
outer 3 miles of the north shore of the bay. Small rafts
of logs and individual logs wore evenly distributed
throughout the rest of the bay, beyond the limits of the
ice, and over a fan-shaped aim of the sea as much as 5
miles from the entrance of tho bay.

Water was still dripping from the wave-washed
slopes around the shore of the bay as high as tho new
trimline on the morning of July 10. Tho volume of
water in streams flowing from Fish Lake and other
lakes reached by tho wave on both the north and south
shores was much larger than normal.

EFFECTS OF THE WAVE
DEBTBUCTION OF VEGETATION

The trimline (upper limit of total or near total
destruction by water of the forest and other vegetation)
along the shores of Lituya Bay is plotted on figure 15
and is illustrated by several photograplis (pis. 3 B, 4Z?,
5 A, 6 B, 7 A and B ) . The altitude at the highest point
on the trimline and at other critical points was meas-
ured by means of an altimeter that was set at mean sea
level, carried up to the trimline, and read again at sea
made within a period of 1 hour or less. The horizontal
level. At most stations the scries of three readings was
position of tho trimline was plotted by transferring its
truce by inspection from the oblique photographs taken
by the writer in 1958 to vertical photographs taken in
1948, and thence to the maj of the bay. Additional alti-
tudes were determined photogrammetrically from the
1948 vertical photographs and from the 1958 U.S. Coast
and Geodetic Survey single-lens vertical photograplis
covering the outer mile of the bay. Prints of some 9-
lens photograplis taken after the 1958 wave were ob-
tained in Februury 1959. Since suitable photogrammet-
ric equipment was not available, they coidd be used only
to add details to the trimlinos in areas of low relief
around the outer part of the bay. A map of Lituya Bay
on a scale of 1 :10,000, with a 50-foot contour interval,
has been compiled from the 9-lens photographs by the
U.S. Coast and Geodetic Survey (H. A. Karo, written
communication, Apr. 28, 1959).

Tho trimline formed by the 1958 wave extended to a
maximum height of 1,720 feet, above mean sea level, on
tho spur southwest of Gilbert Inlet, (pi. 4 B). Its
maximum horizontal distance was about 3,600 feet from
the high-tide shoreline, in the vicinity of Fish Lake.
Along a 1-mile segment midway between the head and
entrance of the bay the band of destruction on the north
and south shores averages 1,200 feet in width and
extends to an average alfitudo of about 110 feet. The
total area between the trimlines and the high-tide shore-
lines in tho bay is about 4 square miles. This figure
includes small lakes and small areas of steep slopes and
beaches where little or no vegetation was growing, but
it is a measure of tho total area over which the wave
was capablo of felling a large proportion of the trees.
Tho total area inundated by the wave is still larger,
probably at least 5 square miles.

One of the most impressive aspects of the 1958 wave
is the thoroughness of its destruction of the forest,
nearly extending to the upper limit of inundation;
this can best bo conveyed by photographs. In most
places the trees were washed out and carried away,
leaving bare ground (pi. 5 A). In some places, mostly
on steep slopes where the roots were anchored in bed-

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GIANT WAVES IN LITUYA BAY, ALASKA

EXPLANATION

July 7, 1958 July 10, 1958
Approximate configuration of shorelirfe,
deltas, and glacier fronts

Trimline (upper limit of destruction of
forest by water)

0 i MILE

1 i i i — . — i 1

Slides inferred to be contemporaneous with
J uly 9 earthquake

Daubed line outlines entire area of fresh tear;
shaded area is main source of slide debris

O 5000 FEET

T . i i | | l

CONTOUR INTERVAL 200 FEET

DATUM IS APPROXIMATE MEAN SEA LEVEL

FiacRi 16. — Detailed map of bead of Lltuya Bay, showing elides, changes in the shoreline and glacier fronts, and trlmllne* result-
ing from the 1988 earthquake and giant ware.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

rock, the trunks were twisted or broken off just above
ground level. At Harbor Point a living spruce tree
was broken off cleanly about 3 feet al)ove the root sys-
tem, where it measured 4 feet in minimum diameter
(pi. !)B). At a few places, mainly at the edge of the
trimline, trees were pushed over but not washed out
(pi. IB, lower left). Only along the outer mile of
the bay were clumps of trees loft standing within the
trimlino. Tho forest was left standing to the high-
tide line at only two points, on the south shox-e 0.4
mile from the entrance and on the nortli shore 1.4 miles
from the entrance (fig. 15). The wave’s competency
is shown also by the sharp trimline and by the narrow
channels cut through the trees on Cenotaph Island (pi.
6 A ) , into a small lake east of Fish Lake and into the
lakes east of Harbor Point. On steeper slopes from
Cenotaph Island toward the heard of the bay the water
had washed into the forest generally not more than 10
to 20 feet vertically above and 30 to 100 feet horizon-
tally beyond the trimlino. On low slopes in the outer
part of tho bay, however, the water at some places
flowed through the foi-est for much greater distances,
probably as much as a quarter of a milo, beyond the
trimline. Salt poisoning of some bushes and plants was
indicated by tho brown tone of the foliage just above
the trimline; this was particularly noticeable on steep
slopes at the head of the bay in late August. The larger
trees showed no effects of tho brief submergence in
salty water, although tho lower trunks of many trees
boi’dcring tho trimlines were injured by impact with
other trees felled or transported by the wave (pi. 6-4).

Many of the trees felled by the 1958 wave were
reduced to bare stems, with the limbs, roots, and even
the bark removed (pi. 6 B). Removal of the projecting
limbs and roots was due to grinding action as the trees
were rotated in the turbulent, water. On many of the
trees, however, the cambium layer was still smooth or
even slippery and showed little evidence of abrasion,
suggesting that water under high pressure or moving
at high velocity stripped off the bark by a process analo-
gous to that used for peeling logs in plywood and
pulpmills.

Along much of the north shore of Lituya Bay and
for short distances along tho south shore and on Ceno-
taph Island part of tho felled timber is concentrated
in poorly defined to well-defined windrows at variable
heights above the high-tide line. The more conspicu-
ous of the windrows are shown on figure 15. The
longest continuous line of debris can lie traced for
about 2 miles along the north shore.

OTHEB EFFECTS

No attempt was made to measure accurately the
amount of erosion accomplished by the 1958 wave, and

probably at only a few points along the shore of the
bay are measurements made or photographs taken
before 1958 sufficiently detailed to allow more than a
rough estimate. F rom the effect on the vegetation an
average minimum thickness of a foot of soil almost
certainly was removed over the entire area between the
trimline and the shore. This alone repx-esents a volume
of more than 4 million cubic yards. Cut banks 1 to
3 feet high were seen along the trimline at some places
in the bay. At the small rounded projection of the
south shore, 1.7 miles east of Harbor Point (fig. 15
loc. A), the wave cut a nearly vertical cliff about 25
feet high into till and underlying stratified sand and
gravel. Large areas of bedrock were newly exposed
and left as bare and clean as though washed down with
a hose on the spur west of Gilbert Inlet, along most of
the steep south shore from Crillon Inlet to a point 1
mile west of Coal Creek, and around much of the shore
of Cenotaph Island.

Marine plants attached to rocks and marine inverte-
brates attached to i-ocks or burrowed in mud or sand
were lai’gely destroyed by the wave, at least down to
mean lower low water level. On Cenotaph Island and
on the south shoi-e of Lituya Bay near the entrance,
where in 1952-53 barnacles and mussels almost com-
pletely covered the rocks in the intertidal zone, and
many edible clams were dug, not one living shellfish was
seen in August 1958. At these localities even the basal
attachment plates of most of the barnacles had been re-
moved from the rocks. The shells of clams, barnacles,
and crabs were scattered along the shore above the
high-tide line and a few were seen at or near the upper
limit reached by the water on Cenotaph Island and at
several other places in the outer half of the bay. F ailure
to find tho remains of any fish or deep-water shells sug-
gests that the wave had little immediate effect on the
larger swimming vertebrates and did not bring up
bottom-dwelling invertebrates from a depth of more
than a few tens of feet The writer had no opportunity
to examine closely the forest adjoining the trimlines
near the entrance of the bay, however, whore the water
flowed out through the trees and whore stranded fish
would most likely bo found. Probably many bottom-
dwelling invertebrates in deep water wei-e killed in
place by settling of sediment eroded and transported
by the wavo. Some fresh-water organisms probably
wox-e also killed by the invasion of salt water into Fish
Lake and smaller lakes and ponds along the shores of
the bay, but these bodies of water were not examined.

Few works of man existed in Lituya Bay at the time
of tho 1958 wave, but judging from the effects on the
vegetation and the boats, the wave would have wreaked
enormous destruction on ordinary buildings and on

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 354 PLATE 3

A. VIEW OF I.ITL’YA BAY. 19SI

Trim line* of the 1936 giant wave* (g) and the 185S-S4 giant wave (A). laicrdl moraine* («) and the end moraine in the right and left foreground record a recent advance
of ice lu the mouth of the bay. Mount Oillon, altitude 12,726 feel. i» the highett peak on the *k>lino

II. VIEW |\ AUGUST 1938

A giant ware generated on July 9, 1938. by m rockdide from the cliff (r) at the head of the hay destroyed I lie foreni over the light urea* to a maximum altitude of 1,720 feel
at d and to a maximum distance of 3.600 feet in from I lie high-tide rhoreline at Fi*h Lake (f’J. A fulling boat anchored in the cove at 6 waa carried over the apit in the
foreground; a boat under way near the entrance waa *unk and a third bout, anchored at r rode out I lie wave

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OKOUMilCAI. 8URVKY

PROFESSIONAL PAPER 354 PLATE 4

.4. NORTH K AST WALL OK CILBERT INLET. At CA ST 195ft

Sbotoft *rar <if rtxkelidc. Ileud of nlidc. at uImiui 3,000 feet altitude. »«* junl liejow mio* field in upper center. Front of l*itu>M (iUrirr at Inner left corner

It. VIEW NORTHW EST AT HEAD OF LITUYA BAY. Al.Cl.ST 195*

I-argc rork»lMlf plunged into (filbert Inlet at loner rijebt corner. dx-aring «* fT part of tlie front of Lituya (Glacier and canning water to turgr over the »pur opposite. The trim-

line (Jo|iea donn to riKbt, armn arar* of nlidea that occurred Intforr tlie 1**58 rartli<|ti.ikc

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GEOLOGIC AI. 81'RVEY

PROPER SION A I. PAPER 3B4 PLATE 3

A. Vif** Meal from Coal Creek, on xoulh ahore of l.ituyu Ujv, Augn»t 1958. Trimlioe at left margin ia at an altitude of alnuit I BO feet, and i» 1,000 feel in from the high-tidr

shoreline

B, Stump of living tprure tree liroketi off by the 1958 itianl ua»e at Heritor Point, mouth of l.ituyu Hay. Brim of Ital U 12 incbea iu diaitirlrr

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OEOLOOICAL 8UBVEY

PROFESSION A!. PAPER 354 PLATE 6

A. VIK1 1 KST ON CKNOTAI'H ISLAND

Miow* ehaimrl cut thrmigh for rut | •> the 1958 gi.ml wave. \ulr injured tree nluiuliiig ul |MXta| of rhtnitel, on right

II. NOKTII SIlOHK OF L1TI ^ A HAY. At GIST »9. r »8

View *• 2 mile* from entrance. Augu-t IQ.'iH; forr*t <i deux am tliat in the upper part of view formerly extended nearly to the 4iorelinc. ^ idlh of gone of ile»truclion l»y the
1958 giant wave o a I tool I, TOO fret at right margin of pltolograph. Note tree* with liniha ami Itark removed, in foreground

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GIANT WAVES IN LITUYA BAY, ALASKA

shore structures such as docks. At the foundation sites,
no trace could be found of the well-constructed cabin on
the west or lee side of Cenotaph Island, used by the
writer as a base camp in 1952 and 1953, or of the light-
house mounted on concrete piers at Harbor Point. A
few cut pieces of wood and some metal utensils from the
cabin on Cenotaph Island were found several hundred
feet from the former site.

Equipment left by a mining company at an intended
campsite near the south shore was washed away (Hen-
rickson, 1959, p. 18). Monuments marking U.S. Coast
and Geodetic Survey triangulation points at Harbor
Point and several other stations along the north and
south shores of the bay are believed to have been washed
out or moved. Station “Ice,” marked by a bronze disk
set in a largo boulder on the shore at the head of the
bay was found by the writer and apparently had not
moved. Markers set in bedrock on the north and south
shores just west of the two arms at the head of the bay,
and one marker set in a concrete post on La Cliaussee
Spit seem, from study of photographs, to have remained
in place also.

With regard to the destructiveness of the wave, R. L.
Wiegel (written communication, Mar. 31, 1959) com-
mented as follows:

The method by which the wave broke and uprooted trees is
easily explained using existing theory and data on wave-induced
forces (Wiegel and Beebe, 1956; Wiegel, Beebe, and Moon,
1957) ; Wiegel and Skjcl, 1958). For example, taking a con-
servative estimate of wave height and water depth, the total
moment about the bottom of a tree 50 feet high with an effective
dense crown diameter of 20 feet and trunk diameter of 2 feet
was computed to be of the order of 25 million foot-pounds, which
la far in excess of the conservative 300,000 foot-pounds neces-
sary to snap the tree or uproot it (Fons and Pong, 1957).

The problem of peeling the bark off a tree is a little more
difficult It may be due to the high water particle velocities in
the waves. A solitary wave 100 feet high moving in water 400
feet deep will have a horizontal component of water particle
velocity in excess of 100 feet per second just under the wave
crest This, combined with the observation in the model that
the wave crest along the edges of the bay moved at the same
velocity as the wave in the center of the bay, indicates that a
water particle velocity of this magnitude would have existed
over a substantial portion of the forested slope. The shear
stress on the bark due to this velocity and extreme hydraulic
roughness of the bark might have been adequate to strip the
hark from the trees, especially as cracks probably formed In
the bark as the trees were being bent prior to breaking.

The water particle velocities along the edges of Cenotaph
Island would have been great also, and this might explain the
stripping of barnacles from the rocks.

The water particle velocities at the bottom of the main por-
tion of the bay would have been much lower.

NATURE! AND CAUSE OF THE WAVE

From the foregoing evidence the nature, sequence,
and approximate time of events associated with the

632776—60 8

July 9, 1958, wave in Lituya Bay are interpreted as
follows:

Beginning at about 10:16 p.m. the southwest side
and probably most of the bottom of Gilbert, and Crillon
Inlets moved northwestward and possibly up relative
to the northeast shore at the head of the bay, on the
opposite side of the Fairweather fault. Observations
of the surface breakage along the Fairweather fault
6 to 10 miles southeast of Crillon Inlet indicate that the
displacement occurred in several pulses and that the
total movement was about 21 feet horizontally and
3 feet vertically (Tocher and Miller, 1959). Intense
shaking in Lituya Bay continued for at least 1 minute
according to the account of William A. Swanson, and
possibly as much as 4 minutes according to Howard
G. Ulrich. Slides and avalanches started in the moun-
tains at the head of the bay within a minute after the
shaking was first felt. Not less than 1 minute nor more
than 2 y 2 minutes after the earthquake was first felt a
large mass of rock slid from the northeast wall of Gil-
bert Inlet. The initial movement of this rock mass,
with attendant clouds of rock dust and avalanching
snow and ice, may account for the “moving glacier”
observed by Swanson. The impact of the large rock-
slide on the surface of the water caused the “deafening
crash” heard by Ulrich and caused a huge sheet of
water to surge up over the spur on the opposite side
of Gilbert Inlet. The sudden displacement of a large
volume of water as the rock mass plunged into Gilbert
Inlet set in motion a giant gravity wave with a steep
front, traveling at high velocity and with its greatest
force directed initially about due south. The gravity
wave, probably supplemented by the surge of water
over the spur southwest of Gilbert Inlet, struck first
against the steep cliffs on the south side of the bay
in the vicinity of Mudslide Creek; the maximum force
of the wave was then reflected and refracted toward
the north shore a little farther out the bay, and again
back to the south shore near Coal Creek. Variations
in the height and intensity of the gravity wave as it
moved out the bay, as recorded in the trimlines, may
have been caused also by the interaction of diagonally
refracted waves, by seiche wave motion, and by reflec-
tion of waves from the narrow entrance. Estimates
by Ulrich and Swanson of the time elapsed from the
first sighting of the wave front until it reached their
boats indicate that the crest of the gravity wave moved
out the bay at an average speed between 97 and 130
miles per hour. After the giant wave passed, the water
in the bay was set into turbulent wave motion and
continued to surge from shore to shore for 25 minutes
or more.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

According to R. L. Wiegel (written communication,
Mar. 31, 1959), the wave speed as calculated from the
estimated time elapsed is in good agreement with the
theoretical speed as calculated from the formula

0=^g(d+B)

where g is the acceleration due to gravity, d is the depth
of water below sea level, and II is the height of the
wave above sea level. He states:

If the water depth averaged between 400 aud SOO feet and
the wave height averaged between 200 and 300 feet the wave
would travel at a theoretical speed of about 100 miles per hour.
If the water depth were taken ns a conservative 400 feet
and the wave height at a conservative 100 feet the theoretical
wave speed would be about SO miles per hour.

From evidence observed and photographed from an
airplane on .July 10, the writer with Kenneth Loken as
pilot, concluded that water had risen to a height of
about 1,800 feet on the spur southwest of Gilbert Inlet
and caused destruction of the forset to the sharp trim-
line across this spur (Daily Alaska Empire, 1958b;
Seismol. Soc. America Bull., 1958, p. 406). This con-
clusion was based on the following evidence: (a) The
“washed” appearance of the bedrock below the trimline
on the spur; (b) the sharp and even appearance of the
trimline, and its similarity to and continuity with the
trimline known to have been caused by water action
farther out the bay; (c) at the highest point on the
trimline, where the 1,800-foot altitude was estimated
from the airplane altimeter, about 30 large trees were
turned upslope and back into the forest. The roots
of some of the upturned trees were bare and white, as
though they had been washed out rather than merely
pulled out of the soil (pi. 7A).

The initial report of wave damage to 1,800 feet above
a water surface was widely doubted both on theoretical
grounds and on the basis of aerial observations and
study of photographs by others. This figure is more
than 8 times the maximum height attributed to a
179) and nearly 8 times the maximum height reached
by the largest of the slide-generated waves in Norway.
Brazee and Jordan (1958), from study of aerial photo-
graphs and evaluation of reports of field ol>servations,
including those of the writer and Don Tocher, con-
cluded that the spur southwest of Gilbert Inlet “has
been denuded to a height of 1,800 feet either by ava-
lanche, wave action or a combination of the two.” Jor-
dan later stated (written communication, Dec. 29, 1958)
“More information is now available and it seems that
landsliding is the major activity for any elevation above
300 feet or so,” and this view is expressed also in an an-
nouncement of plans for a field investigation of Lituya
Bay by the U.S. Coast and Geodetic Survey (Daily
Alaska Empire, 1959). T. N. Davis, from aerial obser-

vations in Lituya Bay on July 12, 1958 first attributed
the destruction of trees at high altitude on the spur
southwest of Gilbert Inlet to “earthslide” (paper read
at Alaska Science Conf., Sept. 2, 1958), but on reexam-
ination of his photographs he found a few trees stripped
of bark high on the slope and now believes that this
damage to the trees is more likely due to action of high.-
volocity water than to slide action alone (written com-
munication, Apr. 6, 1959).

After examining the area of the high trimline again
from the air and on the ground later in the summer, it
is still the writer’s conclusion that water was primarily
responsible for destruction of the forest cover. Exam-
ination on the ground confirmed that trees just above
the highest point on the trimline, at 1,720 feet altitude
as remeasured by a hand-carried altimeter, had been
washed out and overturned by water. At this point
on the crest of the spur the water rose about 20 feet
higher than the highest overturned trees and flowed
across the ridge and at least a quarter of a mile down
the opposite side into the forest, leaving rocks and
driftwood on the moss. It is true that rockslides either
accompanied or closely followed the earthquake on
the northeast side of the spur. Cracks trending par-
allel to the scar were seen in the forest on the crest of
the spur, just above the trimline. Comparison of the
1958 oblique photographs taken after the earthquake
with the 1948 vertical photographs show, however, that
the 1958 slides occurred mainly in old landslide or
rockslide scars, and that the volume of new sliding was
small. Moreover, the trimline which the writer be-
lieves was formed by water, cuts across the tracks of
these slides (pi. 4 B). After the water had dashed over
the spur there was minor sliding from the unstable
scarp at the trimline. The conspicuous streaks of
debris left by small slides on the otherwise washed,
bare bedrock surhice of the southwest face of the spur
(pi. 7 B) provide further convincing evidence against
landsliding or avalanching as the primary cause of
the destruction here. Also, along the margin of the
trimline on the southwest face of the spur from the low
point to an altitude of about 700 feet the trunks of
many large ♦ rccs knocked down but not washed out by
the water are oriented parallel to the trimline, with
their tops turned to the west (pi. 7 Ii). Those trees, if
felled by avalanching or sliding, should lie preferen-
tially oriented parallel to the gradient of the surface.

Small slides occurred, presumably at the time of the
earthquake, on the south side of Lituya Bay between
Mudslide Creek and Crillon Inlet. The area affected
by new slides is much smaller than is shown by Brazee
and Jordan (1958, fig. 3). The trimline formed by

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GIANT WAVES IN LITUYA BAY, ALASKA

the wave continues across this area, between slide scars,
at altitudes ranging from 500 to 600 feet (fig. 16).

The large mass of rock that plunged into Gilbert
Inlet from the northeast wall during the 1958 earth-
quake is referred to as a rockslide in this report, al-
though it is near the borderline between rockslide and
rockfall as defined in two classifications of landslides
(Sharpe, 1938, p. 76-78; Varnes in Eckel, 1958, p.
20-32 and pi. 1). This rockslide as stated on page
63 probably caused the 1958 giant wave at Lituya Bay.
The rockslide occurred in an area of previously active
sliding and gullcying to an altitude of about 3,000 feet
on a slope averaging 40°. The rocks in this area, as
mapped by 1). L. Rossman (written communication,
1957), are mainly amphibole and biotite schists; bed-
ding and schistosity strike about N. 50° W. and dip
steeply northeastward, into the slope.

The new slide area on the northeast, wall of Gilbert
Inlet, as shown on figure 16, was plotted by trans-
ferring the outer limits of the new scar by inspection
from oblique photographs taken after July 9, 1958, to
the vertical photographs taken in 1948, and thence by
photogrammctric met hods to the map. The dimensions
of the slide on the slope are reasonably accurate, but the
thickness of the slide mass normal to the slope can be
estimated only roughly from the data and photographs
now available. The main mass of the slido, as outlined
on figure 16, is a prism of rock that is roughly triangu-
lar in cross section, with dimensions of 2,400 feet and
3,000 feet along the slope, a maximum tliickness of
about 300 feet normal to the slope, and a center of
gravity at about 2,000 feet altitude. From these di-
mensions and an assumed specific gravity of 2.7, the
volume and weight of the rock mass are, respectively,
40 million cubic yards and 90 million tons. It is highly
probable that this entire mass plunged into Gilbert
Inlet as a unit at the time of the earthquake, although
the only known fact is that it fell between about noon
on July 7 and about 10 a.m. on July 10.

The writer went to Lituya Bay in 1958 with a strong
belief that fault displacement was the most likely
mechanism for generating the giant waves originating
in the fault zone at the head of Lituya Bay. The mag-
nitude of the slide on the northeast wall of Gilbert
Inlet was not fully realized from the aerial inspection
on July 10, and it was first considered to l>e only a
minor factor in the generation of the 1958 wave.
Tocher (written communication, Aug. 1, 1958), how-
ever, suggested avalanching of rock or ice from the
northeast wall of Gillxtrt Inlet ns a possible generating
mechanism before he was informed that a rockslide had
occurred there. Arguments advanced by Tocher, infor-
mation obtained later in the field and from the litera-

ture on similar waves elsewhere in the world, and the
model studies made by Wiegel all have contributed to
the writer's present acceptance of the rockslide as the
major, if not the sole cause of the 1958 giant wave.
Among the arguments against fault displacement as an
important contributing mechanism to the generation of
this wave, the following seem most significant: (a)
Eyewitness reports of a lapse of 1 to 2V& minutes
between the onset of the earthquake and the first sight-
ing of tho wave at the head of the bay : (b) The pre-
dominantly horizontal movement along the Fair-
weather fault, as indicated by ground breakage a few
miles southeast of Lituya Bay. If the fault trace lies
near the northeast side of Gilbert and Crillon Inlets,
nearly tho entire area under water at the head of the
bay moved relatively northwestward and possibly up;
wave motion resulting from this displacement should
be directed toward the northwest and southeast side of
the bay and (or) toward the head of the bay. (c) Verti-
cal displacement of the bottom of the bay along the
Fairwcather fault probably would generate waves as a
line source. An eyewitness account and the configura-
tion of the trimlines, however, indicate radial propa-
gation from a point source in Gilbert Inlet.

The comments of R. L. Wiegel on the nature and
cause of the wave follow (written communication,
Mar. 31, 1959) :

It Is a well documented fact that waves with large energy
content are generated impulsively by such varying mechanisms
as underwater seismic disturbances, islands exploding, atomic
bombs, and large masses of water added suddenly to a body
of water. The characteristics of waves generated by such
mechanisms depend upon the disturbing force and the rate at
which it is applied. The resulting waves may be oscillatory
In character, nearly solitary in form, a complex multlcrested
non-linear wave existing entirely above the initial undisturbed
water surface, or a bore (Brins, 1958a, 1958b).

The size of the slide, the water depth, and the general dimen-
sions of Lituya Bay Indicated that a wave similar to a solitary
wuve should form, but with a complex "tali’' to the wave. A
rough model was constructed at the University of California,
at a 1 :1,000 scale. Motion pictures were taken of the model
tests and measurements were made of the water surface time
histories at two points. Observations of the effects of various
types of slides in the model indicated that the prototype must
bnvo fallen almost ns a unit, and very rapidly. If the slide
occurred rapidly then a sheet of water washed up the slope
opposite the landslide to an clevntlon of at least three times
the water depth. At the snme time a large wave, several hun-
dred feet high, moved in a southerly direction, causing a peak
rise to occur in the vicinity of Mudslide Creek. This same
wave swung around into the main portion of Lituya liny, due
to refraction and diffraction. The movements of the main
wave and the tail were complicated within the bay due to
reflections and due to the effect of bottom hydrography. One
further wave characteristic was noticed when large waves were
obtained, and this was that the crest appeared to move at a
nearly uniform velocity across the bay even though the water

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Table 1 . — Data on localized giant waves generated by falling or sliding of solid masses

Location, date. and time of
occurrence

Generating mechanism

Nature of water body, velocity
and height of waves

Effects of waves

Shlxnabara Peninsula, Kyu-
shu Island. May 21. >792,
about 8 p.m.

During period of Intense earth-
quakes and volcanlo activity
about 700 million cu yds of
rock and soil to a maximum
altitude of 1.700 ft on the cast
flank of Mayc-yama slid l*t
miles down a slop* averaging
10*. and plunged Into the sea
along a front 3 mites wide.

Shlmabara Bay. length about 60
miles, average width 10 miles,
maximum depth 210 ft near the
slide; opens Into East China
Scant southwest and. At Shim-
alum 3 vravrs In rupld succes-
sion , the second and largest wave
rblng on land to a maximum
height of about 33 ft.

Treee as much as 9 ft In diameter
felled, buildings destroyed.
More than 15.000 people wore
killed, moist of them by the
warns. Wave dost ruction ox*
tended about 60 mllets along
the shores of the bay.

Langfjord, Feb. 22. 1756....

Loon Lake. Jan. 15. 1905.
about 11 p.m.

Locn Lake, Sept. 13. 193*\
6 a.m.

Locn Lake. Sept. 21, 1936,
in evening.

Loen Lake, Nov. 11, 1936,
at night.

Taflord, April 7, 1934, 3
UD.

NorddaWJord, across from
S trim da, 1938.

About 15.7 million cu yds of bed-
rock and soli to a maximum
altitude of 1.312 ft on the fiord
wall at Tjelle slid down a slope
averaging 25* or more, and
plunged Into the fiord, Land-
slide may have been triggered
by heavy rainfall.

About 450.000 cu yds of bedrock
and talus to a maximum heigh t
of 1.640 ft on Ravnefjell
(Haven Mountain) fell and
slid down a slope averaging
to*, and plunged Into lako.

About 1.3 million cu yds of bed-
rock to a maximum height of
2,625 ft on Havneflell fell at the
same locality as tfie 1505 slide.
Slide about 1,300 ft wide at
iak ashore.

Rockslide or rock fall from
Ravnefjell.

Rockslldo or rockfall from
Ravnefjdl; volume as large as
that on Sept. 13, 1936.

Overhanging rock mass of nearly
2 million cu yds volume fell
from maximum altitude of
2,395 ft on fiord wall with an
average slope of 45°, and
plunged into the fiord along a
front 7W ft wide. RockfaU
triggered by melting of ice In
fractures.

Landslide from Skaflcll.

Longfjord (fiord), length about 20
mile*, average width 1.5 miles,
maximum depth about 1.100 ft;
opens into Nonldalsfjocd to west.
Three waves observed, rblng to
a maximum height of 130 ft on
shore opposite tne slide.

Loen Lake, length 7 miles, aver-
age width 0.6 mile, maximum
depth 436 ft. Wave 10 ft high
in middle of lake; roec to maxi-
mum height of 131 ft on shore
opposite the slide and to 19 ft
at the far end of the lake, 4.8
miles from the slide.

Loen Luke, see above. Wave ap-
peared 3-6 ft high In center of
lake: It rose to a maximum
height of 230 on shore opporite
the slide, and to 50 ft at the fir
end of the lake.

Loen Lake, see above. Wave rose
to maximum height of 49 ft on
shore.

Lo*n Lake, see above. Wave rate
to about the same height as on
Sept. 13.

Taljord (fiord), length about 5.6
miles, average width 0.7 mile,
maximum depth 700 ft; opens
into Norddalsflord to west.
Three waves of Increasing height
were observed nt several places.
Water rose to maximum Wight
of 204 ft about 050 ft from tho
slide margin, to >22 ft on shore
opposite tho slide, and to 3 ft
above normal hlgh-tido line
about 31 miles from the slide.
Approximately measured veloci-
ties range from 13.4 to 26.8 miles
per hour.

NorddnWJord (fiord). Three
waves reported.

Vegetation, soil, buildings, and
boats destroyed, 32 iwople
killed. Effects of the waves
were noticed as much as 25
miles from slide.

Vegetation, soli, buildings, and
boats destroyed; Iron steam-
boat 48 ft long was carried 830
ft and stranded 56 ft above
lake level; 61 people kJllod.

Vegetation, soil, buildings,
boats and bridges destroyed,
73 peoplo killed. Remains of
stranded steamboat carried
on up to 164 ft above lake
level.

Basts used for rescue work were
damaged.

Nothing left to destroy

Vegetation, soil, buildings, and
boats destroyed, 44 people
killed along fiord within 2
miles of tho slide; extensive
damage to boats and docks as
much as 31 miles from the
slide.

Not described In reference.

United States

Disenchantment Bay,
Alaska, July 4, itttt.

Reel Terraco ares no;»r
Kettle Pulls, Columbia
River valley, Washing-
ton; from April 8, 1911. to
Aug. >9, 1953.

Mouth of Hawk Creek near
Lincoln. Columbia River
valley, Washington, July
27, 1949.

East side of Columbia River
valley north of Kettlo
Falls, Washington, Fob.
23, 1951.

Fallen Olacler, a hanging gla-
cier about 3,500 ft long and
1,200 ft wide, avalanched from
an altitude of 1,000 ft down a
sloj* averaging about 16*. and
plunged into bay along a front
0.5 mile wide.

Landslides In terrace scarps
underlain by bedded uncon-
solidated deposits. Narrow
segments of the scarp on
sloi>o averaging about 23°
suddenly gave way and slid
Into the lake. Debris came
down from maximum height
of 210 ft obove water level.

Landslide in terrace scarp under-
lain by bedded unconsoli-
dated deposits. A narrow
segment ot the scarp on a slono
averaging about 31° suddenly
guve way and slid into tho
lake. Debris came down from
maximum height of 340 ft
above lake level.

Debrk? si Ido In bedded uncon-
soildatod deposit! and talus
from maximum height of sev-
ers! hundred foot above lako
level.

Disenchantment Bay, length
about >0 mites, average width 3
miles, maximum depth 912 ft;
opens into Yakutit Bay to
south and Into Rti&ell Fiord to
east. Waves 15-20 ft high ob-
served for half an hour on Rus-
aoll Fiord >5 mlle< from the ava-
lanche; water rose to maximum
height of 115 ft about 2.5 miles
from the avalanche.

Franklin I>. Roosevelt Lake,
average width 5,000 ft, maxi-
mum depth 160 ft at slide ore*.
Wave* were generated by at
leusi 11 different slides; the
largest wave rose to maximum
height of 65 ft on oppoelte shore,
ana was observed o miles un the
lake. Observed volocttv of one
series of waves was about 45
mikes i •or hour.

Franklin D. Roorevelt Lake, in
bay about 1,200 ft wide and 120
ft drep at slide tree. Wave
rore 66 ft on shore opposite the
slide.

Franklin D. Roorevelt Lako.

Unconsolidated deposits eroded,
busts* broken off or washed
out; area uninhabited.

Vegetation destroyed, uncon-
solidated deposits eroded;
barges and boats broke loose
from dock 6 miles from slide
area.

Trees knocked down.

Not described In references.

References

Omori (1907); Ogawa (1924, p.
219-224, pis. 6, 7>.

Jrfrstad (1956).

Holmsen (1936, p. 173-177. firs.
2. 3); Bugge (1937. especially
figs. 1. 8. and 10); Brigham
(1906); Holtedahl (1953, p. 1044-
1045).

Jlolmren (1936, p. 183-186, photo-

E fj opposite p. 176): Bugge
, figs. 8 and 10. p. 357);
txlnhl (1953, p. 1045-1046).

Kolmsen (1936, p. 186).

Holmsen (1936, p. 190), supple-
ment, In German.

K ah Idol and Kolderup (1937);
Holmwn (1936, p. 177-183, figs.
4 and 5); Bugge (1037. espe-
cially figs. 4. 5 tuid 6); Iloltedahl
(1953, p. 1046).

J0ratad (1956, p. 330). Incidental
mention only; no detailed de-
scription found.

Tore (1909, p. 67-68). According
to Indian legend foiling glaciers
in this area generated similar
waves at least twice before;
reportedly 100 Indians were
killed by a ware 3bout 1845.

F. O. Jon« and W. L. Poterson
(written communications.
Mar. 16 and May 7, 1959);
Jones in Eckel (1958, figs. 31,
32. p. 40-41).

F. O. Jones and W. L. Petereon
(written communications.
Mar. 16 and May 7, 1959).

Jonea in Eckel (IMS, fig. 23 on p.
33); W. L. Peterson (written
communication, May 7, 1959).

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GIANT WAVES IN LITUYA BAT, ALASKA

depths at the edge were considerably less than the water
depth In the center of the channel. It Is believed that this phe-
nomenon Is associated with the phenomenon studied by Per-
roud (1057).’ The model study movies showed that the wnvo
elevation was higher along the edges of the bay than In the
center.

The action of the wave over the center of Cenotaph Island
and at La Chaussee Spit are due to shoaling effects which
have not been studied In detail for solitary, or similar, waves.

The energy In a solitary wave 100 feet high In water 400
feet deep with a channel width of 8,000 feet can be computed
using an equation given by Ippen and Mitchell (1957). It Is
about 6X10“ foot-pounds. The potential energy of the land-
slide was about 3.5X10“ foot-pounds. Hence, only about 2 per-
cent of the potential energy of the slide went Into the main
wave. This Is of the same order of magnitude ns obtained by
model studies of a similar type of disturbance (Wlegel, 1955).

COMPABiBLE WAVE8 IN OTHER PARTS OF THE
WORLD

Waves similar to the 1958 giant, wave in Lituya Bay
have been generated by the sliding of part of a moun-
tain into Sliimabara Bay in Japan, by the sliding or
falling of large masses of rock into a lake and several
fiords in Norway, by the avalanching of a hanging
glacier into a bay in Alaska, and by landslides into a
lake in Washington. References and significant data
on several such localized waves that have come to the
writer’s attention are summarized on table 1. An ex-
haustive search of the literature no doubt would reveal
many other such occurrences in parts of the world
where steep or unstable slopes are adjacent to bodies of
water. Earthquakes acted as a triggering mechanism
for the slide in Japan, but no earthquake was reported
at the time of the 1905 wave in Alaska or at the time
of any of the large waves in Nonvay and Washington.
Some waves that accompanied earthquakes in uninhab-
ited or sparsely inhabited areas and were attributed to
tectonic movement, as for example the 1899 wave in
Yakutat and Disenchantment Bays and Russell Fiord
in Alaska (Tarr and Martin, 1912, p. 46-47) may
have been generated instead by slides or avalanches
triggered by the earthquakes. On the other hand one
interpretation of the April 2, 1868 tsunami on the south
coast of the Island of Hawaii as the result of a mudflow
(Omori, 1907, p. 144) is not correct, according to G. A.
Macdonald (written communication, Apr. 15, 1959),

WAVES ON OCTOBER 27, 1930
BETTING AND SOURCES OF INFORMATION

Four men were in Lituya Bay on October 27, 1936.
James Huscroft and B. V. Allen were in a cabin on
the west shore of Cenotaph Island (fig. 17) and Nick

•Perrood, P. H„ 1D57, The •ollturj’ wnve reflection Along a ntrnlRht
Tcrtlcal wall at oblique Incidence: Calif, fnlv., (Berkeley), Ph.D.
thesis. 93 p.

Larsen and F. H. Frederickson were on a 38-foot
trolling boat The Mine. Larsen and Frederickson, who
had entered Lituya Bay on October 26, anchored their
boat first near the north shore south of Fish Lake and,
after the first wave was sighted, moved to the west shore
of the island near the cabin. According to the most
detailed accounts, there were three giant waves in close
succession, beginning at about 7 :00 a.m., about an hour
before sunrise. According to Frederickson the weather
was clear but it was too dark to see much at the head
of the bay ; moreover, after The Mine was moved to the
lee of Cenotaph Island, the head of the bay was hidden
from all four observers. The tide at the time of the
waves was flooding and nbout at mean tide stage (U.S.
Coast and Geodetic Survey, 1935).

Two nearly identical articles based on an oral report
by Allen (called to the writers attention by Robert De
Armond, oral communication, July 22, 1958) were pub-
lished in newspapers soon after the waves occurred
(Alaska Daily Press, 1936; Alaska Weekly, 1936).
Information related by Huscroft about a year later
was incorporated in an article on Lituya Bay by Wil-
liams ( 1938) . De Armond also recalled seeing another
account in a Ketchikan newspaper, based on the oral
report by Larsen and Frederickson, but attempts to
find this article have failed (L. II. Bayers, written
communication, Apr. 7, 1959) . The eyewitness account
of F. II. Frederickson is abstracted from his recollec-
tions as related to the writer in a telephone conversation
and a let ter in September 1958.

EYEWITNE88 ACCOUNTS
ACCOUNT OF FRED H. FREDRICKSON

During the night of October 26-27, 1936, The Mine
was anchored near the north shore of Lituya Bay, a
mile due west of the cabin on Cenotaph Island (fig. 17).
About 2 hours before sunrise on October 27, at about
6 :20 a.m. local time, a loud, steady roar was heard. It
seemed to be coming from the mountains beyond the
head of the bay, but, although the weather was clear,
it was too dark to see much there. No shaking was felt
on the boat The roar continued until about 6 :50 a.m.,
at which time a large wave was first seen in the narrow
part of the bay, just west of the two arms at the head.
The wave at this position appeared as a steep wall of
water extending from shore to shore and possibly 100
feet high. On first sighting the wave the men raised
the anchor and started the boat toward the Cenotaph
Island ; an estimated 10 minutes later, when the first
wave arrived, the boat had reached a position about
1,300 feet northwest of the cabin, in the water at least
70 feet deep. No lowering or any other unusual dis-

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

turbance of the water surface was noticed up to this
time.

The first wave raised The Mine about 50 feet above
normal water level ; out of the lee of the island, to the
north and south, the wave was possibly 50 feet higher.
Immediately after the passing of the first wave the
water surface fell below normal level. Huscroft’s sein-
ing boat, anchored nearby in 48 feet of water, touched
bottom. The first wave was followed at estimated 2-
minute intervals by the second and third waves, each
larger than the preceding one. The water surface
receded below normal level after each of these waves
also. Smaller waves continued for about half an hour
after the third large wave passed. The direction of
wave movement was always toward the mouth of the
bay; there was no sloshing of the water back and forth
in the bay. Floating logs and ice appeared around the
boat about half an hour after the third large wave
passed.

ACC0UNT8 OF BERNARD V. ALLEN AND JAMES HDBOROFT

The more complete of two newspaper articles based
on the account of Allen (Alaska Daily Press, 1936)
states that he and Huscroft were awakened at 7 :00 a.m.
on October 27, 1936, by a roar like “the drone of 100
airplanes at, low altitude,” to find the water already up
to their cabin on Cenotaph Island. As seen from a
higher, safer point on the island, the water is described
by Allen as sweeping over the shore in 3 waves of in-
creasing altitude, at an estimated velocity of about 20
knots (23 miles per hour). In the published account
the maximum height of the waves is given at 250 feet,
but in a shorter account recorded in the log book of Osa
Noldo (Caroline Jensen, written communication, Dec.
23, 1958) Allen stated that the waves reached a height
of from 150 to 200 feet. These accounts agree in most
respects with the recollections of Fredrickson; in the
log book, however, Allen described the weather in

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GIANT WAVES IN LITUYA BAY, ALASKA

Lituya Bay on October 27, 1936, as cool, with rain, hail,
thunder, and lightning.

The observations attributed to Huscroft by Williams
(1938) differ from the other accounts in tho following
respects: Huscroft was preparing breakfast in his
cabin at the time the roar was first heard; the water
rushed toward the entrance in a single “mountainous
tidal wave” followed by an immense “back wave,” and
then by waves that surged and resurged over the length
of the bay a number of times. This was on a morning
in the fall of 1936, during a period of unusually heavy
rainfall.

EFFECTS OF THE WAVES

The observations attributed to Huscroft by Williams
of Lituya Bay by the 1936 waves, as shown on figure 17,
was mapped from field oliscrvations made by members
of U.S. Geological Survey field parties in 1952-53, from
single-lens vertical photograplis at a scale of about
1 : 40,000, taken in 1948 by the U.S. Navy, and from an
oblique aerial photograph taken in 1937 by Bradford
Washburn. The upper limit of wave destruction
around much of the imier part of the bay is readily
seen on the 1948 vertical aerial photographs due to the
difference in tone, texture, and average height of the
vegetation growing above and below the trimline.
Around tho outer part of the bay and on some steep
slopes near the head of the bay, however, field examina-
tion was required to determine the effects of the 1936
wave. At several places on steep slopes in the upper
part of the bay the upper limit of wave destruction was
no longer recognizable even in the field, due to the
scarcity of large trees. The altitude of the trimline was
measured at 14 points by means of a hand-carried
altimeter, and at other points using the Kelsh plotter.

The identity of the trimline with the known 1936
wave was confirmed by tree ring counts in two ways :
(a) sections cut in 1953 from the largest trees among
the three principal types growing below the trimline
on the northwest shore near point h (fig. 17), showed
the following ages: cottonwood, 17 years; alder, 15
years; spruce, 14 years; (b) a section cut from a tree
just above the trimline at point k (fig. 17, pi. 8A),
showed, on the side toward tho bay, an injury believed
to have been caused by debris carried by the waves
(pi. 85). The section showed 17 annual growth rings
outside the injury. The tree-ring counts were made by
R. M. Godman of the Alaska Forest Research Center
R. F. Taylor, written communications, Oct, 26 and
Nov. 20, 1953). The second method (see page 77), was
used to date the oldest, known trimline in Lituya Bay.
The assumption that tho injuries were caused by the
waves was convincingly confirmed by the many simi-

larly damaged trees found along tho trimline of tho
1958 wave (pi. 6A).

The trimline of the 1936 waves has a maximum
height of 490 feet or more nliove sea level on the north-
east wall of Crillon Inlet (pi. 9.4). The exact upper
limit of wave destruction could not be determined by
field examination in this area in 1953, due to the scanty
growth of trees on the steep slope and to the possibility
that the alincment of trees at the position tentatively
mapped as tho trimlino was accidental. The position
mapped in the field was later confirmed by an aerial
photograph taken in 1937 by Bradford Washburn,
on which the slope below the trimline is virtually bare
of vegetation. Destruction of the forest extended to a
maximum distance of 2,000 feet from the shoreline
in the reentrant northeast of Cenotaph Island. Along
a 1-mile segment midway along tho bay — the same
reference interval cited for the 1958 wave on page 60 —
the band of destruction on the north and south shores
averages 50 feet in width and extends to an average
altitude of 10 feet. The total area between the trim-
lines of tho 1936 waves and the high tide shoreline
is about 0.8 square mile.

Much of tho evidence of destruction by the 1936
waves was obliterated by the wave in 1958. Short
segments of the 1936 trimline still remained above
the 1958 trimline from Cascade Glacier northwest
about 1,500 feet and about 3,000 feet along the north-
east wall of Crillon Inlet,

The total destruction of the forest up to a sharp trim-
line by the 1936 waves is mentioned in all of the avail-
able eyewitness accounts and is recorded in photo-
graplis taken during the latter part of 1936 by Tom
Smith. One of these photograplis is reproduced as
plate 95. Allen (Alaska Daily Press, 1936) reported
that trees and shrubs were cleared away to a maximum
altitude of 400 feet. The same article reported that
within a few days uprooted trees had drifted along the
beach as much as 50 miles south of Lituya Bay. Fred-
rickson (written communication, Sept. 1958) said that
although not many trees were felled in the outer part
of the bay, tho water flowed for some distance out
through tho forest. Crabs and clams were found as
much as half a mile back from the beach north of the
mouth of the bay. According to Fredrickson most
of the trees felled by the waves were washed out by
the roots but still had roots, limbs and bark attached
after the waves had passed. This difference in the
damage caused by the 1936 waves, as compared to that
caused by the 1958 wave is confirmed also by other
eyewitness accounts and by the photographs taken by
Smith.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

One of the accounts attributed to Allen (Alaska
Daily Press, 1936) describes the 1936 “flood” as “cut-
ting a new bank from the soil and stone, and hurling
rocks and trees.” Williams (1938, p. 18), either from
information furnished by Huscroft or from his own
observations in 1937, states that “corrasion was com-
plete down to bedrock, including all forest growth and
even boulders 10 feet or more in diameter.” This was
not true in all areas below the trimline, for the photo-
graphs taken by Smith show stretches northwest of
Cascade Glacier and along the north shore of the bay
where many trees wore left lying at or near their
original positions. Even after the 1958 wave the bed-
rock was not exposed at many places touched by the
1936 waves. In 1952-53 scarps as much as 4 feet high
were seen at a few places along the 1936 trimline; at
most places, however, evidence indicated removal of
not more than a thin soil layer containing the root
systems of the trees. The erosive power of the 1936
waves, even at the head of the bay, was much less than
that of the 1958 wave.

The 1936 waves (only the third wave according to
Fredrickson and to one account by Allen) washed
into Huscroft’s cabin on the west shore of Cenotaph
Island without causing much damage, but destroyed at
least two small frame buildings nearby. Two tri-
angulation stations established by the U.S. Coast and
Geodetic Survey in 1926 could not be found in 1940
(U.S. Coast and Geodetic Survey “Lithographic List
of Descriptions of Triangulation Stations, Alaska No.
57,” not dated). One was on the north shore near
Cenotaph Island marked by bronze disks set in boulders
and one was on the south shore at Coal Creek marked
by concrete blocks. Don Tocher (oral communication,
Sept. 2, 1958) suggested that these markers may have
been carried away or moved by the 1936 waves.

NATURE AND CAUSE OF THE WAVES

All eyewitness accounts agree that the 1936 waves
were preceded by or accompanied by a loud noise, and
the two most detailed accounts agree that there
were three waves of increasing size in the vicinity of
Cenotaph Island, with estimates of maximum height
ranging from 100 to 250 feet. The account of one of
the men on the boat, in a lxdtcr posit ion for observation
than the men on the island, indicates that the roaring
noise from the head of the bay was heard as much
as half an hour before the first wave was sighted. This
account also indicates that the waves were spaced about
2 minutes apart, and were followed by recession of the
water below normal level. One observer on the island
estimated the rate of water movement (not necessarily
the speed of the waves) at about 23 miles per hour.

The time required for the first wave to travel from
near the head of the bay to the west side of Cenotaph
Island, as estimated by one observer on the boat, gives
a speed of about 22 miles per hour. Evidence pre-
served in the trimlines indicates that the waves were
generated at or near the head of Crillon Inlet, where
at least one of them dashed up on the valley wall to a
height of 490 feet or more. The maximum height of
the trimlines near Cenotaph Island is 24 feet, suggest-
ing that the observers’ estimates of the height of the
waves at this position in the bay is too large.

Possibly significant in the consideration of the origin
of the 1936 waves is the fact that they occurred “during
a period of unusually heavy rainfall” (Williams, 1938,
p. 18). Although two eyewitness accounts differ as to
the weather on the day of the waves, the weather rec-
ords at other places in southeastern Alaska do indi-
cate that the occurrence of these waves was preceded
by heavy rainfall (U.S. Weather Bureau, 1938). At
the two coastal stations nearest Lituya Bay — Sitka (fig.
14), and Cape St. Elias, about 260 miles northwest of
Lituya Bay — precipitation averaged 45 percent above
normal for the entire month of October 1936, and 150
percent above normal for the 6-day period preceding
October 27. At the tliree nearest inland stations —
Juneau, Iluines, and Skagway (fig. 14) — precipitation
averaged 42 percent, above normal for the month of
October, and 111 percent above normal for the 6-day
period preceding October 27. Those departures are
based on weather records through 1957 (U.S. Weather
Bureau, 1958).

Allen, in both the published account (Alaska Daily
Press, 1936) and in the account related to Nolde (Jen-
sen, Caroline, written communication, Dec. 23, 1958),
attributed the 1936 destructive “flood” and waves in
Lituya Bay to the sudden draining of an ice-dammed
lake in the basin of North Crillon Glacier. Williams
(1938, p. 18) presented tins hypothesis in detail, show-
ing in a diagram the supposed course followed by the
wall of water as it rushed down the surface of the gla-
cier and into the head of Crillon Inlet Williams (writ-
ten communication, Mar. 3, 1954) stated that when he
visited Lituya Bay after the “flood” (in 1937) he
climbed along the sides of the Crillon Glacier and no-
ticed the highwater marks there.

Floods duo to the sudden draining of ice-dammed
lakes are a frequent and well-known phenomenon in
southern Alaska, and it is understandable that this
hypothesis was proposed and generally accepted as the
cause of the destruction in Lituya Bay in 1936. In
papers given orally in 1954 the writer presented evi-
dence opposing the ice-dammed lake hypothesis as fol-
lows: North Crillon Glacier is an actively moving,

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GIANT WAVES IN LITUYA BAY, ALASKA

much crevassed stream of ice that has an average gradi-
ent of about 500 feet per mile; its drainage basin, now
mapped from vertical aerial photographs and well
known from aerial and ground observations (D. L.
Rossman, written communication, 1957), lacks any
topographic configuration in which a large body of
water could 1)6 ponded, unless it is a chamber con-
cealed beneath the glacier. An aerial photograph
taken by Bradford Washburn in June 1937, less than
a year after the supposed “flood,” shows no derange-
ment of the surficial moraine patterns on the surface
of the lower part of North Crillon Glacier, such as
certainly should have occurred if water had flowed
down over the surface of the ice as inferred by Wil-
liams. The high-water marks mentioned by Williams
may have been the scars of fresh rockslides.

Crillon Lake, into which the South Crillon Glacier
discharges (pi. 2), has been mentioned also as the lake
that drained at the time of the 1936 waves. Seismic
investigation by Goldthwait (1936, p. 508), indicates,
however, that the bedrock sill on the divide beneath
the drainage of North Crillon Glacier into Lituya Bay
and South Crillon Glacier into Crillon Lake is about at
the same level as the surface of the lake.

The writer, after reviewing the evidence available
in 1954, concluded that serious objections could be
raised against many of the possible causes of the 1936
waves that had been suggested until then, and that
conclusive support could not l>e marshaled for any of
them. Despite the additional evidence obtained since
then about the 1936 waves and despite the wealth of
information gained from the 1958 wave, this opinion
is still held as this report is written. It is necessary
therefore, as in 1954, to present several possible causes,
some more convincing than others, but none definitely
proven.

8UDDEN DRAINING OF AN ICE-DAMMED BODY OF WATER

The writer has already given convincing arguments
opposing the hypothesis of surface drainage from an
ice-dammed lake in the North Crillon Glacier basin,
although tliis hypothesis perhaps best explains the
roaring sound heard before the waves were seen.

Two other variations of this hypothesis warrant con-
sideration: (a) The water could have been ponded
in a chamber within or beneath the North Crillon
Glacier, or on the divide separating the drain-
age of the North and South Crillon Glaciers, then
suddenly released beneath the glacier or through an
ice tunnel below sea level in the tidal front of North
Crillon Glacier. This might account for the sudden
upwelling immediately in front of the glacier. How-
ever it seems unlikely that a chamber of sufficient
size could form in a glacier as active as North Crillon.

Also, if the chamber were very high in the glacier, as
would be required to obtain a substantial hydraulic
head, it seems unlikely that the water could have jetted
out rapidly enough to generate giant waves, (b) A
partly subglacial lake is present now, and existed in
1936 in the trench tributary to Gilbert Inlet, just north-
west of the sharp bend in the Lituya Glacier (pi. 2).
Aside from the probability of relatively slow drainage
from this lake, it is also unlikely that drainage from
beneath the Lituya Glacier would set up waves that
rose highest at the opposite end of the trough forming
the head of Lituya Bay.

FAULT DISPLACEMENT

In 1954, displacement along the Fairweather fault
was suggested as a possible cause of the 1936 “flood
wave,” although evidence of an earthquake was lacking
(Miller, 1954). Through the eyewitness accounts that
were obtained since then, the date and approximate
hour of occurrence of the 1936 waves are now known
and it is possible to state definitely that no earthquake
was felt in Lituya Bay and that no earthquake with
an epicenter near Lituya Bay was recorded at that
time on seismographs at Sitka, Alaska, or more dis-
tant stations (Tocher, Don, written communication,
Aug. 1, 1958). Perry Byerly (oral communication,
Jan. 22, 1954) believes that fault displacement suf-
ficiently large to cause the waves could not fail to
have caused an earthquake that would havo been felt
in the bay and recorded at seismographic stations more
distant than Sitka. Therefore, it seems that fault dis-
placement can be ruled out as a cause for the 1936
waves.

ROCKSLIDE, AVALANCHE, OR LANDSLIDE

The roaring sound reported by three eyewitnesses
to the 1936 waves and said by one of the ol>servers
to have come from the head of the bay and to have
preceded the waves, suggests a rockslido or avalanche.
Some of the observed differences between the 1936 and
1958 waves, particularly the occurrence of three waves
of increasing size in 1936, and the much higher velocity
of the 1958 wave, might be advanced as an argument
against a common origin. On the other hand, these
differences in the wave patterns might be due to dif-
ferences in the location of the sliding or falling rock
mass and the manner in which it entered the water.
This was demonstrated in 1934 in Tafjord, Norway,
where a rockfall generated waves of about the same
height and velocity as the 1936 waves in Lituya Bay,
and where three waves of increasing height were ob-
served (Kaldhol and Kolderup, 1937; table 1, this
report). Three waves reportedly were generated also
by two other landslides into Norwegian fiords, Lang-

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

fjord in 1746 and Norddalsfjord in 1938 (J>rstad,
1956, p. 326, 330-331).

By analogy with the 1958 wave, a falling mass that
caused (he 1936 waves in Lituya Bay should have come
from tho southwest wall of Crillon Inlet, opposite
the high point on the trimline. None of the previously
published eyewitness accounts mention any evidence
that a large mass of rock or ice had fallen into Lituya
Bay at the time of the 1936 waves, and Fredrickson
(written communication, Sept, 1958) states that he did
not. notice any such evidence when he went to the head
of the bay a short time after the waves had occurred.
Comparison of the trilens photographs of Lituya Bay
taken in 1929 by the U.S. Navy with the 1948 vertical
photographs indicate that sliding had occurred on the
valley wall above and just south of tho front of North
Crillon Glacier at some time between 1929 and 1948.
This slide scar, however, is directly above the delta
that formed in front of North Crillon Glacier before
1929, and some evidence of a largo slide in 1936 should
have been preserved on the delta and should be visible
in the 1948 photographs. The 1929 and 1948 photo-
graphs show scattered large blocks of rock on the delta
surface, also small talus cones along the base of the
cliff, suggesting that sliding in this area has taken
place frequently but in small increments.

Elsewhere on both walls of Crillon Inlet the corre-
spondence between the 1929 and 1948 photographs is
so close, even as to individual trees, gulleys, and other
distinctive patterns, ns to definitely eliminate the pos-
sibility that a large slide occurred during this interval.
Small fields of permanent snow and ice are on the
northeast wall of Crillon Inlet above 3,400 feet alti-
tude, but these too show close correspondence in shape
and size on photographs taken by Bradford Washburn
in 1934 and 1937, eliminating the possibility of a large
avalanche. There is a possibility that a rockslido or
avalanche of ice fell on the North Crillon Glacier
causing movement that was transmitted through the
glacier to the tidal front. This possibility may be
eliminated at least for the lower 2 miles of the glacier
by inspection of the 1937 photographs; it seems un-
likely that any movement higher on the glacier would
be transmitted to the front.

Tho photographs indicate the occurrence of small
rookslides into Gilbert. Inlet from both the southwest
and northeast sides, and into Lituya Bay between Mud-
slide Creek and Crillon Inlet, at some time between
1929 and 1948, but these locations are all incompatible
with the trimline pattern of the 1936 waves. If the
writer’s interpretations of the photographs are cor-
rect, and falling or sliding of a mass of a size greater
than a few thousand cubic yards info Crillon Inlet is

required to generate the 1936 waves, then landsliding
or avalanching may virtually be eliminated as a possible
cause.

SUBMARINE SLIDING

Submarine slides (submarine “landslides”) have
long been included among two or more hypothetical
causes of tsunamis in the oceans. For example, Guten-
berg (1939), and Shepard, Macdonald and Cox (1950, p.
394-395), offer opposing viewpoints. The tsunami as-
sociated with the 1908 earthquake in the St raits of Mes-
sina has been attributed to a turbidity current
originating in a submarine slump (Heezen, 1957) . Re-
cent laboratory experimental work indicates that sub-
marine slides are capable of generating tsunamis
(Wiegel, 1955).

Soundings in Crillon and Gilbert Inlets indicate
slopes of as much as 28°, through vertical distances of
nearly 500 feet. Unconsolidated material was avail-
able in 1936 in tho deltas built out from the fronts of
both North Crillon and Lituyn Glaciers, and may have
lieen present in substantial thickness at other places
around the head of the bay. Submarine slides could
also have occurred in bedrock. Perhaps one of the
most attractive aspects of submarine sliding as a pos-
sible cause of the 1936 waves is that it cannot be defi-
nitely disproved because the evidence, if any, is hidden
beneath the bay. Considering the magnitude of the
slopes available and the probability that a large sub-
marine slide would involve material at least partly
above water, submarine sliding seems unlikely as the
cause of tho 1936 waves, however. Unless two or more
slides occurred in close succession, or the waves were
reflected at the head of the bay, it is difficult to account
for the observed fact that the third wave, rather than
the first, was the largest.

MOVEMENT OE A TIDAL GLACIER FRONT

The trimlines at the head of Lituya Bay show clearly
that at least tho largest of the 1936 waves was gener-
ated at or near tho tidal front of North Crillon Glacier,
and attained maximum height, on the northeast wall
of Crillon Inlet within 3,500 feet of the glacier front
This evidence, reinforced by the known generation of
waves at. tho fronts of other glaciers that discharge
into water, lends strong support to some kind of move-
ment of tho Crillon Glacier front as the cause of the
1936 waves. Three typos of movement must bo consid-
ered : (a) calving of ice from the subaerial part of a gla-
cier front into the water; (b) calving and sudden
surfacing of ice from a submarine projection of a gla-
cier front; and (c) almost instantaneous forward move-
ment of a glacier front. One aspect, of the 1936 wave
pattern, tho occurrence of three waves of increasing

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(SKOLOttlCAL SURVEY

PROFESSIONAL PAPER 354 PLATE 7

.4. Tree* Mirhol mil and turned upalope by «mlrr ul altitude of 1.720 fret. Small •dide* occurred on alrep «i»|ie ut n*lit during (lie 195H earthquake, but destruction of forrtl

in middle and loser Irfi part of view m due mainly to water

B. Weal aide of spur; note waabed appearance of l>edrock at lower right. in contra*! to alide area juat below tritulinc at i. Height of \ iew. from bay at lower left to upper right

corner, i» about 1,200 feel

SPUR SOUTHWEST OF GILBERT INLET. AUGUST 1938

C.KOUMSICAI. SURVEY

PROFESSIONAL PAPER 3S4 PLATE R

■4 North sliore of I,itu«a IU> briHrrn OmiUph Island <imI t.ilhcrt Inlet. sltowing furr*li of different ajirt in so nr denuded hy 19.16 giant warn (shore to ll, in ii|>per pert of
suite drnuile«l l»> guiiit Mate jIhhiI IH?I (A to /), in upper part of Mine denuded |i> giant wave sis 1853 or 1854 (/ to A), in upper part of reeently glaciated sone |(- to «*■>,
anil above lateral moraine at m. Mmlograph taken in 1953

It. Seetion i iit in l')S3 from »|irui'e tree growing just above trimline of 1936 giant wave* (lor. A. in A and in fig. IT).

There are IT growth rings outside injur v on right

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OKOMMilt’AI. KI KVBY

PROFESSION A I. PAPER 354 i'l.ATK tl

A. OilUm Inlrt and brail of I.iluya Hay in 1952; Trintlinr begin* above tidal front of North Oillon (ilarar; altitude 190 fret at i. Front of (atraiir Glacier at left margin

B. I>eatriiction to an altitndr of uIhiui 90 fert at head of Lituya Hay, half a mile northwest of Qicade Glacier. Photograph hy Tom Smith in 1930

DESTRUCTION OF FOREST BY 1936 GIANT WAVES

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GEOLOGICAL 81

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SECTION c:i I IN 1953 FHOM SPRUCE THEE CROWING JUST A HOVE TRIM LINE OF 1853-54 GIANT WAVE
'llwrf *rr 100 grow th ring* mit«i<lr injury on right. Um mIiIv (I.), on figorr 19

GIANT WAVES IN LITOYA BAY, ALASKA

height in the vicinity of Cenotaph Island, could be ex-
plained either by repeated movements of any of these
three types, or by interference, refraction or reflection
of waves near the point of generation at the head of the
bay. Calving from an ice front could have caused the
roaring sound reported by eyewitnesses, although it
seems unlikely that calving could have occurred con-
tinuously for as much as half an hour before the first
wave was sighted.

No photograplis showing the North Crillon Glacier
front shortly before or shortly after the occurrence of
the 1936 waves are available, but oblique aerial photo-
graphs taken by Bradford Washburn in the summer of
1934 and in June 1937 show little change in the position
and configuration of the northeast half of the front.
The delta and southwest half of the front on Crillon
Inlet are not shown on the 1937 photographs. Based
on the photographs taken in 1934, and assuming little
change in the following 2 years, the tidal front of
North Crillon Glacier at a time just preceding the
occurrence of the 1936 waves was a nearly vertical wall
of ice about 2,700 feet long and 200 to 300 feet above
water level, extending across about half of the total
width of Crillon Inlet (fig. 17). If the ice front
extended to the bottom of the inlet, as seems likely, its
maximum height below water level was about 290 feet.

Calving of subaorial ice into water has been observed
at the fronts of many glaciers discharging into lakes,
rivers, bays, and even into the open ocean in Alaska,
as well as in many other parts of the world. From
observation or indirect evidence such calving has
formed waves capable of eroding as much as 5 feet
above high tide a mile or more from the ice front (Tarr,
1909, p. 33-34), but according to available data no
waves even approaching the magnitude of the 1936
waves in Lituya Bay have resulted from glacier calv-
ing in Alaska. If calving were the cause of the giant
waves in 1936, such waves should occur with greater
frequency, not only in Lituya Bay but also at the fronts
of many other tidal glaciers in Alaska. This would be
true unless, as suggested by C. C. Bates (written com-
munication, Apr. 7, 1955), simultaneous calving from
two or more glacier fronts is a further requirement.

In the course of the model study of Lituya Bay,
R. L. Wiegel and Don Tocher found that rotational
fall of a partly submerged weight with a flat face, sim-
ulating the Crillon Glacier tidal front, formed wave
traces that compare closely in configuration to the trim-
lines on the walls of Crillon Inlet. The maximum
height reached by the wave in the model, however, was
about equal to the height of the face of the weight, above
water level. This gives some basis for doubting that
ice falling from the Crillon Glacier front could have

raised a wave to a height much greater than the height
of the front. C. C. Bates (written communication,
Apr. 7, 1955) suggested that although ice falling from
the front of North Crillon Glacier might provide only
about 10 percent of the necessary volume increment, the
remainder of the rise indicated by the trimline on the
northeast shore of Crillon Inlet might come from up-
rush or local refraction effects.

Submarine calving from the glacier front was sug-
gested as a possible cause of the 1936 waves by W. O.
Field, Jr. ( written communication, Dec. 5, 1952) . Evi-
dence of ice projecting below water level as much as
1,000 feet beyond the subaerial part of glacier fronts
has been reported for glaciers in the Yakutat Bay area
( Russell, 1891, p. 101-102 ; Tarr, 1909, p. 31-32) . Field
states that waves 25 feet or more in height are formed
by calving of projecting submarine ice masses at the
front of Muir Glacier in Glacier Bay. The configura-
tion of the submarine parts of the tidal ice fronts in
Lituya Bay is not known. The possibility that the
deltas in front of the Lituya Glacier may have been
underlain by ice was mentioned on page 60. In the
few hours that cither or both the North Crillon and
Lituya Glacier fronts were in sight during the 1952,
1953, and 1958 field investigations, the writer did not
see any calving of submarine ice. The appearance of
the delta in front of North Crillon Glacier in the 1948
vertical photographs does not give evidence of disturb-
ance by the sudden rise of an ice mass beneath it, and
the remaining tidal part of the glacial front seems to
be too small to provide a mass of sufficient size to gen-
erate the 1936 waves.

Slippage of an ice mass over its floor is generally
accepted by glaciologists as a major mechanism of
movement for glaciers on slopes (Sharp, 1954, p. 826).
However, an instantaneous advance of a glacier front
of more than a few inches has not been proven. Pros-
pectors in Disenchantment Bay reported that during
the largest of the Yakutat Bay earthquake shocks, on
September 10, 1899, the tidal front of the Hubbard
Glacier advanced or was thrust forward from one-half
to three-quarters of a mile, but Tarr and Martin (1912,
p. 16) believed this to be an erroneous inteq>rctat ion
of the enormous calving of ice from the glacier front.
It seems likely that forward movement of the Crillon
Glacier front of a few feet or even a few tens of feet
would bo required to raise a wave to the height indi-
cated by the 1936 trimline in Crillon Inlet. Such
movement of the glacier front should have disrupted
the surface of the glacier for some distance above the
front to such an extent that the changes should be evi-
dent on photographs taken in 1937 and later. An
oblique aerial photograph taken by Bradford Wash-

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

burn in June 1937 shows no unusual crevassing or dis-
ruption of the surficial moraine patterns on North
Crillon Glacier.

TSUNAMI IN THE OCEAN

Perry Bycrly and J. P. Eaton (oral communication,
Jan. 22, 1954) offered the suggestion that wave motion
from a tsunami generated at sea might be transmitted
either through the narrow entrance or through the spit
at the mouth of Lituya Bay, causing a seiche wave or
some other type to form inside the bay. In further
support of this suggestion Byerly (written communi-
cation, Feb. 1, 1954) called attention to the following
statement by McNown (1952, p. 163) : “It has been
amply proved that the motion produced in a port can
have an amplitude not only equal to but even a number
of times greater than the amplitude of the wave that
produces it. Furthermore, from theoretical considera-
tions, this amplitude can occur equally well with an
entrance width that is extremely small.”

According to tide-gage records (Neuman, 1938, p. 26)
no tsunami occurred in the northeastern Pacific Ocean
in October 1936. It is difficult, also, to understand how
wave motion introduced at the mouth of Lituya Bay
could have been transmitted without any obvious sur-
face effects to the head of the bay, thero to be amplified
into three giant waves that traveled out the bay at high
velocity.

OTHER POSSIBLE CAUSES

For the sake of completeness several other agents
capable of generating waves are mentioned, although
thero is little or no evidence to recommend them as pos-
sible causes of the 1936 waves in Lituya Bay. Subma-
rine volcanic act i vity is known to have given rise to large
tsunamis in the sea, as, for example, the destruction of
Krakatoa in 1883 (Williams, 1941, p. 255-256, 261).
Waves caused by tidal action and by wind are well
known. As examples of water waves set in motion by
air waves, Press (1956) cited a sea wave with a 2-foot
amplitude that followed the Krakatoa explosion, and
a 10-foot wave at Chicago in 1954. Finally, Olaf
Holtednhl (oral communication, 1957) suggested that
a falling meteorite be added to the list of possible causes.

WAVES BETWEEN 1864 AND 1916

EYEWITNE88 ACCOUNTS

When the writer first visited Lituya Bay in 1952
stories of “floods” were heard from several fishermen
who anchored their boats in the bay. One described
catastrophic floods caused by breaking of a glacial lake
near the head of the bay in 1890 and again in 1928.
Another mentioned a flood about 1899 that destroyed
a native village and a fish saltery near the mouth of
the bay, and a second flood about 1928, when Huscroft

was living on Cenotaph Island. Others reported that
both floods occurred after sharp earthquakes. It is
clear now that these accounts referred at least in part
to the 1936 and 1853-54 waves, but the mention of dates
1890-99, of earthquakes, and of a saltery near the
mouth of the bay suggest the occurrence of another
wave of intermediate age. In 1958 James Betts of
Angoon, Alaska reported thnt his grandfather had
experienced a flood or wave in Lituya Bay in 1899
(Tom Smith, oral communication, Aug. 1958). The
writer has been unable to obtain further information
on this report.

OTHER EVIDENCE

Possible evidence for the occurrence of at least, one
giant wave in Lituya Bay between the 1853-54 wave
and the 1936 waves was first noticed during the 1953
field investigation, on the north shore near the mouth
of the creek draining from Fish Lake. At this local-
ity, in a nnrnow belt midway between the 1936 and
1853-54 trimlines, the spruce and hemlock trees
appeared to be a little smaller in average size than in
the forest adjoining and just below the 1853-54 trim-
line. This impression was not tested at the time by sec-
tioning the trees. In the course of later study of
ground photographs taken in 1917, photographs of the
north shore of the bay between Cenotaph Island and
Gilbert Inlet (J. B. Mertie, nos. 601, 605, 619, and 620,
U.S. Geological Survey Photolibrary, Denver) showed
not only the 1853-54 trimline but also, in the interval
about 0.8 to 1.8 miles west of Gilbert Inlet, a probable
lower trimlino that had about the same height and con-
figuration as the 1936 trimline in the same area. This
segment can be identified with certainty as a trim-
line on a photograph taken in 1894 by a Canadian
Boundary Survey party (McArthur no. 128; print
loaned by W. O. Field, jr., Mar. 3, 1950). The lower
trimline in this area shows faintly on the 1929 tri-
lens photographs and on these can be traced west-
ward along the north shore, with decreasing certainty,
to the locality of the field observation near Fish Lake.
The eastward extent of this trimline near Gilbert Inlet
is also uncertain. It probably falls to or near the
shoreline, as shown on figure 18, but the photograph
taken in 1894 suggests that it may rise eastward to
or nearly to the 1853-54 trimline in this area.

Possible trimlines that may be at lenst in part
younger than the definitely identified trimline on the
north shore are shown in ground photographs taken
in 1916 by Trevor Davis (oral communication, July
1958) near Cascade Glacier and on the spurs south-
west of Gilbert and Crillon Inlets, and in photographs
of the north shore of Anchorage Cove taken in 1917
(Mertie nos. 98, 99). The supposed trimline at Cas-

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GIANT WAVES IN LITUYA BAT, ALASKA

cade Glacier is recognizable on the 1929 trilens photo-
graphs and can be projected about a mile to the south-
east as an irregular lower limit of scattered clumps
and groves of spruce trees. A few scattered spruce
trees of about the same size are standing below this
line, however. None of these supposed trimlines
shown on 1916 and later photographs can be recognized
on the few copies of 1894 photographs that are avail-
able, but because of incomplete coverage and the poor
quality of some of the prints, their existence at that
time cannot bo disproved.

DATES

The lower trimline definitely identified in a photo-
graph of tho north shore of Lituya Bay taken in 1894
indicates that at least one giant wave occurred before
this date but later than the 1858-54 wave. The stage of
vegetation growth below the lower trimline, as shown
on the photograph, suggests that the trimline was
formed about midway in the interval 1854 to 1894.
Hence the “evidence of flooding and washing” noted
in 1874 by Dali (1888, p. 203) may have resulted from
this wave.

The other possible trimlines shown on 1916-17
photographs, on the basis of the previously mentioned
unsubstantiated eyewitness account and on the basis
of the stage of vegetation growth, are attributed
tentatively to a wave occurring in 1899. The occur-
rence during that year of the great Yakutat Bay earth-
quakes and the report of a great amount of drift
timber and muddy water in the ocean between Cape
Fairweather and Yakutat 2 days after the largest of
the earthquake shocks (Tarr and Martin, 1912, p. 79)
are further evidence for this date. Tho absence of
any reference to Lituya Bay among tho many reports
of those who experienced the Yakutat Bay earthquakes
probably means either that no report was received by
Tarr and Martin (1912, p. 65-68) or that no one
was in Lituya Bay at that time, because the shocks
were felt throughout a large area in southern Alaska
and adjacent Canada.

EFFECT8 OP THE WAVES

The trimlines plotted on figure 18 were reconstructed
mainly from the 1916 photographs by Davis and the
1929 trilens photograplis. Altitudes on the trimlines
were obtained by transferring points by inspection to
the 1948 vertical photographs, from which the approxi-
mate height above water level was then estimated or
measured photogrammetrically. Trimlines formed by
two different waves were tentatively identified. The
older wave apparently destroyed all or nearly all vege-
tation up to a sharp trimline for a distance of 4 miles

or more along the north shore. A maximum altitude
of 80 feet and a maximum width of 2,100 feet back
from the high-tide line were measured for this trim-
line. The younger wave destroyed vegetation to a
maximum altitude of about 200 feet on the northeast
shore of Crillon Inlet and to lesser heights on the spurs
southwest of Gilbert and Crillon Inlets, and possibly
to a height of a few feet on the north shore of Anchor-
age Cove. On the south shore of Lituya Bay, west of
Mudslide Creek, destruction of vegetation by either
wave, if any, must have been limited to a narrow zone
bordering the beach. The total area of substantial de-
struction of vegetation below all of the tentatively iden-
tified trimlines in less than 0.4 square mile. Most of
the evidence of destruction by the waves between 1854
and 1916 was removed by the 1936 wave and any re-
maining evidence was wiped out by the 1958 wave.

NATURE AND OAU8E OP THE WAVES

Photographs taken in 1894 by McArthur (nos. 105A,
128) show fresh, bare surfaces on the upper slopes
of the northeast wall of Gilbert Inlet and the valley
of Mudslide Creek, suggesting that slides had occurred
in these areas not long before. It is doubtful that the
older wave wns generated by a slide from the north-
east wall of Gilbert Inlet, because McArthur’s photo-
graphs do not show a trimline on the opposite shore
of Gilbert Inlet. By analogy with the 1958 wave,
destruction of vegetation should have been greatest
there. A slide in the valley of Mudslide Creek could
account for the maximum known destruction obliquely
opposite on the north shore of the bay, and also for
tho absence of a conspicuous trimline in the inlets at
the head of the bay.

The trimline of the wave inferred to have occurred
about 1899, as reconstructed from photographs, com-
pares most closely in magnitude and configuration with
the trimline of the 1936 waves. It seems likely, there-
fore, that the 1899 (?) wave was generated in Crillon
Inlet, possibly by the same unknown mechanism that
caused the 1936 waves. However, if a wave did occur
at the time of one of the great earthquake shocks in 1899,
displacement, along the Fairweather fault warrants con-
sideration as a possible cause. By analogy with the 1958
wave, a rockslide into Crillon Inlet must also be con-
sidered. St. Amand (1957, p. 1357-59) suggested that
at. least one of the earthquakes in 1899 resulted from
movement on the Fairweather fault Evidence in sup-
port- of this suggestion was found by Tocher and Miller
(1959) after tho 1958 earthquake. New surface breaks
were seen from the air near the scarps on Nunatak
Fiord described by Tarr and Martin (1912, p. 37-40) ;
along the Fairweather fault southeast of Lituya Bay

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Fioc** 18. — Map of Utuya Bay, showing trimllnw of one or more giant waves that occurred between 1804 and 1918.

much of the new breakage had taken place along old
scarps. The few oblique photographs taken at the head
of Lituya Bay at the turn of the century are not ade-
quate to either prove or disprove the occurrence of
a rockslide in Crillon Inlet.

WAVE IN 1808 OR 1804
EYEWITNESS ACCOUNTS

Williams (1938, p. 19) related the formation of the
oldest trimline in Lituya Bay to an old Indian story
about the catastrophic destruction of a village near the
entrance. The source of this legend was not cited.
Emmons (1911, p. 294-298) and de Laguna (1953, p.
55) wore told the story of the meeting between La
Perouse and the Tlingit in Lituya Bay in 1786 by
natives living at Yakutat, near Juneau, and at Angoon.
Emmons (1911, p. 295) also recorded the Tlingit legend
about a monster who dwelt in Lituya Bay near the

entrance and who, with his assistant, caused tidal waves
by grasping the surface of the water and shaking it as
if it were a sheet De Laguna (written communication,
Nov. 19, 1957) was told a story about a flood in Dry
Bay that killed a great many people, possibly between
1850 and I860, and also the story of a village near Dry
Bay that was abandoned about 1850 because eight canoe
loads of men from the village were lost in Lituya Bay
when their canoes tipped over. W. A. Soboleff (oral
communication, June 7, 1958) was unable to find any
specific information about Lituya Bay among the
people of Tlingit origin in the Juneau area, other than
that the Indians had left the bay for an unknown reason
and at an unknown date. Theeo stories may indeed
refer to the giant wave that formed a trimline in Lituya
Bay in 1853 or 1854, but some of the stories might also
rofer to incidents related to the treacherous tidal cur-
rent in the entrance or to an earlier or later wave.

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GIANT WAVES IN UTDVA BAY, ALASKA

None of these stories are of any value for determining
the nature and cause of the 1853-54 wave or for dating
the wave more accurately.

OTHEB EVIDENCE

The only positive evidence now known for the occur-
rence of a giant wave in Lituya Bay in 1853-54 — the
destruction of vegetation along the shores — is clearly
recorded on many photographs taken between 1894 and
1954. The evidence was also studied in the field in
1952-53. Only two segments of the 1853-54 trimline,
totaling about a mile in length, remain on the north
shore of the bay since the 1958 wave.

DATE

An approximate date of late 1853 or early 1854 for
the occurrence of the oldest known giant wave in Lituya
Bay was obtained from a tree ring count using the
second method described on page 69. A section cut
by Rossman and Plafker from a large spruce tree grow-
ing just above the oldest trimline at point L on figure
19 showed an injury on the side toward the bay (pi.
10). According to R. L. Godman of the Alaska Forest
Research Center (R. F. Taylor, written communica-
tion, Oct. 26, 1953) the injury occurred after the end
of the 1853 growing season and before the beginning
of the 1854 growing season, or between mid-August
and the early part of May. Rossman and Plafker
estimated the age of the largest spruce tree seen in the
forest below the trimline at this site in 1953 to be about
92 years.

EFTECT8 OF THE WAVE

The trimline formed by the 1853-54 wave, as shown
on figure 19, was mapped from field observations in
1952 and 1953, and from the single-lens verticle photo-
graphs taken in 1948. The altitude of the trimline was
measured on the ground at. 12 points with an altimeter,
and at other points with a Kelsh plotter. Destruction
of the forest by the 1853-54 wave seems to have been
complete up to a sharp trimline that is easily seen
on the 1948 vertical photographs and on oblique photo-
graphs ( pi. 8A ) of the north shore west of Gilbert Inlet,
around Cenotaph Island, and from Coal Creek west
on the south shore. These trimlines seem to intersect
the beach about 1V& miles inside the entrance, on the
north shore, and about 2 miles inside the entrance on
the south shore. A trimline to a maximum height of
18 feet was identified by field examination in 1953
for a short distance along the steep slope north of The
Paps. In 1953, along both shores in the outer part of
the bay, and on La Chaussee Spit, spruce trees older
than 100 years were found growing to the edge of the
forest above the beach.

Field examination in 1953 indicated that on the
spur southwest of Gilbert Inlet the trimline sloped
down, and also became gradually less well defined
toward the east. This is confirmed by McArthur’s
photograph (no. 128), taken in 1894. No evidence of
the trimline was found, either in the field or on the
photographs, along the walls of Gilbert and Crillon
Inlets or on the south shore between Crillon Inlet and
Mudslide Creek. This could be due to the scarcity of
large trees on these steep slopes, but probably the wave
had little effect at the head of the bay or along the
south shore at Mudslide Creek.

Destruction of the forest on the shores of Lituya Bay
by the giant wave in 1853 or 1854 extended to a maxi-
mum height of 395 feet above mean sea level and to a
maximum horizontal distance of 2,500 feet inland from
the high-tide shoreline, a total area of at least 1 square
mile. In the 1-mile long segment used as a reference
for comparison with the other waves (p. 60, 69) the
band of destruction on the north and south shores aver-
ages about 620 feet in width and about 80 feet in alti-
tude. Scarps as much as 25 feet high were seen at a
few places along the trimline of the 1853-54 wave.
These scarps, plus the evidence of the effects on the
forest, indicate that the erosive power of the giant wave
in 1853 or 1854 was comparable to that of the 1958
wave, although it did not affect as large an area. Part
of the trees remained standing at the sites of the native
dwellings shown at the shore near the entrance of the
bay on the map of La Perouse (1798, opposite p. 146).
However, the water almost certainly inundated these
sites and may have destroyed the village, as indicated
by native legend and by the observations in 1874 by
Dali (1883, p. 203).

NATURE AND OAUBE OF THE WAVE

At the present time (1959) the only basis for specula-
tion on the nature and cause of the 1853-54 wave is a
comparison of its effects on the vegetation with the
effects of the two most recent giant waves in Lituya
Bay. In extent and thoroughness of its destruction, the
1853-54 wave compares most closely with the 1958
wave. From the configuration of its trimline the
1853-54 wave probably was generated at or near
the head of the bay, but either at a different point
or by a different cause than the 1958 wave.

A rockslide from the steep wall on the south side
of Lituya Bay at the present position of or just east
of Mudslide Creek (fig. 19) seemingly would best ac-
count for the maximum known height of destruction
almost directly opposite on the north shore of the bay.
It would also account for the minimum destruction or
total lack of destruction of vegetation on the south

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

shore in the vicinity of Mudslide Creek, in Gilbert Inlet
and in Crillon Inlet. Tho valley of Mudslide Creek,
and particularly the east wall of the valley, is an area
of active sliding at the present time, and sliding in the
past probably played an important part in the forma-
tion of the valley. Photographs taken in 1894 by
McArthur (nos. 105 A and 128) show that the shape
of the Mudslide Creek valley was similar to that shown
on the 1948 vertical photographs, so any major sliding
must have occurred before 1894. The sketch map of
Lituya Bay made in 1874 and issued in 1875 as U.S.
Coast Survey Chart 742 is almost identical to the La
Perouso map in the part of the bay east of Cenotaph
Island, indicating that little or no resurveying was

done in the upper part of the bay. Hence a comparison
of those maps gives no information on the possible oc-
currence of a large slide at Mudslide Creek between
1786 and 1874. The modem U.S. Coast and Geodetic
Survey chart of Lituya Bay (no. 8505) shows a more
pronounced bulge in the shoreline at Mudslide Creek
than does the La Perouse map. The difference is slight
and, in view of the small scale and questionable ac-
curacy of the La Perouse map, only suggests but does
not prove that a large slide occurred there sometime
after 1786.

No major earthquakes in tho region adjoining Lituya
Bay are known to have been reported between 1847
(Dali, 1870, p. 342) and 1862 or 1863 (Musketov and

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GIANT WAVES IN LITUYA BAY, ALASKA

Orlov, 1893, p. 349, 386). The paucity of records for
this period in Alaska, however, cannot be taken as proof
that no earthquake occurred in conjunction with the
1853-54 wave in Lituya Bay.

POSSIBILITY OF FUTURE WAVES

Giant waves have occurred in Lituya Bay at least
four times, and possibly five times within 105 years, or
on the average, once every 21 to 26 years. Hence,
based on the historical record only, the odds against
one of these waves occurring on any single day spent
in the bay are comfortably large (about 9,000 to 1).
The writer believes that the odds may be much less
than this at the present time because of a larger than
average potential for slides resulting from (a) shak-
ing and ground breakage associated with the 1958
earthquake; (b) removal of vegetation and uncon-
solidated deposits by the 1958 wave. Areas especially
susceptible to sliding are outlined in figure 20. The
rockslide on the northeast wall of Gilbert Inlet in 1958
created new unstable slopes at the head of the slide
scar and along its southeast margin. Planes of weak-
ness parallel to bedding or schistosity in the upper part
of the 1958 rockslide area continue southeastward
toward Cascade Glacier; Tocher, in August 1958 (oral
communication) from the air noticed open fractures
along some of these planes just southeast of the slide
scar. In the field during the same month the writer
found many open fractures above and generally paral-
lel to steep slopes at altitudes ranging from 1,700 to
2,500 feet along the crests of the spurs southwest of
Gilbert and Crillon Inlets. Destruction of vegetation
by the 1958 wave will result in accelerated erosion of
unconsolidated deposits by running water for some
time to come, and therefore in further undermining
of steep and unstable slopes.

F urther movement along the Fairweather fault, par-
ticularly of the magnitude of the 1958 movement, could
cause new slides from steep slopes around the head
of Lituya Bay. Slides could also be started by freezing
and thawing of water in the open fractures during
the spring or fall, by unusually heavy rainfall, or
merely by rock or soil failure without any triggering
mechanism. In addition to the subaerial slides there
may be at least one other mechanism, not yet identified,
that has generated one or more giant waves in Lituya
Bay in the past and might do so again in the future.

Whatever the odds against their occurring during
any given short period of time, the giant waves prob-
ably will occur in Lituya Bay in the future ; this poten-
tial danger should be known to those who enter the
bay. Steady increase in the permanent and transient
population of Alaska, as well as the development of

the Glacier Bay National Monument, under normal
circumstances, would result in steadily increasing use
of Lituya Bay as a harbor for small boats and land-
ing place for amphibious aircraft and, eventually, in
permanent settlement. Before the 1958 wave the U.S.
National Park Sendee was considering Lituya Bay
as a site for a ranger station, for, despite the then
known hazard of the entrance and the somewhat vague
history of earlier waves, the bay is advantageously
located on the coastline of the Glacier Bay National
Monument and affords the only protected anchorage
for many miles in cither direction along the coast
(Mitchell, L. J., written communication, Mar. 13,
1959) . The giant waves thus have increased the diffi-
culty of providing safe access to this part of the
National Monument, but at the same time they have
greatly enhanced the interest in the bay and its value
for recreational and scientific purposes.

SUMMARY AND CONCLUSIONS

A rockslide triggered either by movement on the
Fairweather fault or the accompanying shaking, on
July 9, 1958 plunged into Gilbert. Inlet, causing water
to surge over the opposite wall of the inlet to an alti-
tude of about 1,740 feet and generating a gravity wave
that moved out from the head of Lituya Bay at a speed
of about 100 miles per hour. Field investigation indi-
cates that this surge and the giant water wave wore
primarily responsible for the nearly total destruction
of the forest up to a sharp trimline that has a maxi-
mum altitude of about 1,720 feet opposite the rockslide
and extends along the shores of the bay to the mouth.
This conclusion is supported by R. L. Wiegel’s study
of a model of Lituya Bay and his calculations from
existing theory and data on wave hydraulics.

The giant waves that rose to a maximum height of
490 feet in Lituya Bay on October 27, 1936 were gen-
erated in Crillon Inlet by some disturbance other than
the previously reported flood of water from an ice-
dammed lake in the basin of North Crillon Glacier.
The waves of 1936 were not associated with an earth-
quake, and evidence is lacking that a largo subaerial
slide into Crillon Inlet caused them. Among other
possible causes, movement of a tidal glacier front or
submarine sliding seem the most plausible, but none
are conclusively supported by the information at hand.
Further study of a hydraulic model of Lituya Bay will
probably bo the most fruitful method of solving the
problem of the origin of the 1936 waves. However,
the necessary clue or clues may be found in contem-
porary photographs or observations not available in
the present investigation, or in the literature on similar
waves elsewhere.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

IOOO

CONTOUR INTERVAL 1000 FEET

DATUM IS MEAN SEA LEVEL
DASHED CONTOURS APPROXIMATELY LOCATED IN
1958 SLIDE SCARS

EXPLANATION

• • • • ■ ■*• *•«•(

Open fractures seen or photo-
graphed in August 1958

Areas belived to bo especially
susceptible to sliding

Delta

FTocfta 20. — Map of head of Utuya Bay, showing open fractures and areas believed to be especially susceptible to sliding.

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GIANT WAVES IN LITUYA BAT, ALASKA

Unsubstantiated oral accounts, and a possible trim-
line shown on photographs taken in 1916 and later,
suggest that a wave 200 feet high may have been gen-
erated by a disturbance in Crillon Inlet at the time of
one of the great earthquakes in 1899.

A trimline having a maximum altitude of about 80
feet on the north shore of Lituya Bay, shown clearly in
photographs taken in 1894, records a giant wave that
occurred after 1854 and is tentatively dated about 1874.
The configuration of the trimline, as partly recon-
structed from photographs, suggests sliding in the
vicinity of Mudslide Creek as the cause of this wave.

A trimline having a maximum height of 395 feet on
the north shore records the earliest known giant wave
in Lituya Bay. Based on a tree-ring count, this wave
occurred in late 1853 or early 1854. Configuration of
the trimline suggests sliding in the vicinity of Mud-
slide Creek as the cause. No major earthquakes are
known to have occurred in southern Alaska during 1853
or 1854.

The fact that giant waves have occurred more fre-
quently in Lituya Bay than in other seemingly similar
bays may be due to the following factors in combina-
tion: (a) Presence of an active fault under water at
the head of the bay ; (b) presence of recently glaciated,
steep slopes on highly fractured and sheared rocks
along the fault zone; (c) presence of deep water imme-
diately below the steep slopes in and near the fault
zone; (d) heavy rainfall and frequent freezing and
thawing. The glaciers discharging into the head of
the bay along the fault zone may also contribute to
generation of the waves, but little direct evidence is
available now to support this.

The potential for generation of localized but enor-
mously destructive waves by the falling or sliding of
solid masses into water deserves wider recognition by
geologists, by engineers concerned with the planning
of dams and reservoirs, and by anyone concerned
with the safety or permanency of structures or
equipment near the water level in lakes or bays
that adjoin steep slopes. Many of the fiordlike in-
land waterways of southeastern Alaska, for example,
have the necessary topographic and hydrographic
requirements and seemingly are susceptible to the oc-
currence of localized waves comparable in magnitude
to those in Lituya Bay, although much less frequently
than in Lituya Bay.

The 1958 giant wave in Lituya Bay affords geolo-
gists and biologists an example of catastrophic de-
struction of plant and animal life, and also an
opportunity to study the rate and nature of reestablish-
ment of marine life in the intertidal and nearshore

zones, and of plant life in the recently denuded zone
above the shoreline.

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INDEX

Pane

Acknowledgments 53

Aerial observations . .... — — 53, 59, 84, 05, 69, 75, 79

equipment for 53

Aerial photographs, evidence for giant wave* 53,

57, 69, 60. 04. 69. 71, 77, 79, 81

Age determinations, radiocarbon ..... 65

Alaska Forest Research Center 63, 69, 77

Allen, B. V„ account by 67, 68

Anchorage Cove — .... 58, 59. 74, 75

Angoon, Alaska 74, 76

BoaU In area of giant waves, Badger 57. 58, 59

Rdrle — — — ..... ... 57

L ’Astrolabe ..... ..... — .. — ... 66

Steven R. Cappt 53

Sunmore ......... 57, 58

Boulder till 55

Calving of Ice ..... .............. .... 72, 73

Cape Falrwcather._._._._ ... — _ 75

Cape Spencer 54, 59

Cape 8t. Ellas .... ... — ... 70

Cascade Glacier 64. 60, 61, 69. 70. 74, 79

Cenotaph Island 54, 56. 58, 57, 58. 59, 62, 63, 67, 68, 70, 74. 77, 78

Coal Creek 55, 62, 63. 70. 77

Crlllon Glacier 70, 72, 78

Crlllon Inlet 54,55, 59.

60. 61, 62, 63, 64, 65, 69, 70, 72, 73. 74. 75. 77, 78, 79. 81
Crlllon Lake 55, 71

Destruction by wares, marine Invertebrates 62, 69

vegetation 67, 60, 62, 69. 75. 77, 79 ; pi. 5A

works of man 62. 63. 70. 74. 76. 77

Disenchantment Bay ... 67, 73

Dixon Harbor ..... 58, 59

Dry Bay 76

Earthquake, epicenter

on July 9. 1958

origin

Earthquakes, between 1847 and 1862 or 1863.

In Japan

in Norway

In Washington..........................

Takutat Bay, 1899

Erosion, unconsolidated deposits

wave of 1936

Exploration of area, American

French ...

Russian

Eyewitness accounts

53, 65, 57. 58. 59, 64. 79

55, 67

78, 81

55, 75

57,69,79

66,66

56, 57. 58. 59. 67, 08. 76

Falrweather fault, displacement 55,63,65.71,75,79

relative movement 53, 55

Falrweather Range 53, 54, 65

Field observations 65, 56, 64, 69. 77, 79

Fish Lake 54.00,02.67,74

Forest, ages 64.55,37,77

Fredrickson, F. H„ eyewitness account 67, 68

Future waves, susceptible areas ... 79. 80

Geography of area 63, 54

Geologic setting 55

Giant waves, Interpretation 53, 63, 04, 65, 67

Gilbert Inlet.. 53. 59. 60, 61, 62, 63, 64. 65. 71, 74. 75. 77. 78, 79 : pi. 4 B

Glacial draft 55

Glaciation, post- Wisconsin .... 65

Page

Glacier Bay ..... 63, 59, 73

Glacier Bay National Monument 53. 57, 79

Gulf of Alaska 51, 58. 67

Haines. Alaska 70

Harbor Point 62,83

History of area 51, 53, 55, 66

Hubbard Glacier, tidal front ... 73

Huscroft, James, account by 67, 88

Ice blocks, floating, dimensions 69

Ice'datumed lakes ........ .......... 70, 71, 79

Juneau, Alaska

63, 70, 70

Ketchikan newspaper .... 67

Krusof Island ..... 69

La Chauasee Spit

La Perouse expedition

map and chart ....

Lltuya Bay, geography

laboratory model

location

Lltuya Glacier, dimensions.

location

movement

origin

54, 57. 69, 63, 77

51. 65, 56

56, 77, 78

63,61

78, 79

54,59

55,61,71

58. 69. 00, 72, 78
54

Mctamorphlc rocks, dlorlte

schist

slate

Moraines ...

Mudslide Creek ...

Muir Glacier

- 65

55,65

54.65,71,74

58. 61. 63, 64, 72, 75, 77, 78, 81
73

North Crlllon Glacier 64.65.68,60.61,70,71,72.78,74,79

Number of waves, evidence ... 67

Nuuatak Fiord 55, 75

Palma Bay ..... 55

Petroleum Investigations .................... 51

I'botogrnmmetrlc methods ..... 60, 65, 75, 77

Placer gold 56

Precipitation 54. 69, 70. 81

Reforestation, sequence ..... 54, 55, 69. 75

Rockslldes. cause 67,75,78.79

Crlllon Inlet 72, 76

Gilbert Inlet 00,81.63,84.65,72.75,76.79

Mudslide Creek 75,77.81

volume 65. 72

Salisbury Sound 59

Sedimentary rocks, age ... ... ... 51, 55

graywackc ... 55

Seiche, wave motion 63. 74

Sitka, Alaska 53,59,70,71

Sitka National Monument 53

Sitka Sound 59

Skngway, Alaska 70

Solomon Railroad 64

South Crlllon Glacier 71

St. Ellas Mountains ...... 53, 65

Submarine contours ...... 54

Submarine sliding 72

Swanson, W. A., account by ...... .... 68, 59

Temperature .... 54

Tertiary rocks 61, 65

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INDEX

Pat*

The Pap* 84. 77 ; pi. 2

Tidal current. Telocity 82, 84. 87. 76

Tidal glacier front, movement 72, 79. 81

Tllnglt tribe, language ................. ... 84

legend 76, 77

population ............... 86

Tree*, generic and specific name* 84

Ainu*, sp 84

Chamaccyparia noot kat mala 64

Plcca altchcnaia 84

Populut trichocorpa ......................... 84

Tauga hctrrophylla 84

mertmaiana 54

Trlmllnes, age 51, 82, 55. 67. 69, 74. 75

altitude 51. 53. 54, 60. 61. 63. 64, 69. 78. 77, 79. 81

as evidence of waves 87

cause ........................................ 52

deflnttlon 60

Tsunamis 50, 64. 67, 72, 74

Turbidity currents 72

Page

U.8. Coast and Geodetic Survey, aerial observations 53

soundings by .... .... 54

Wave on July 9, 1958, cause 83, 59, 68. 79

effect on tide gage - ...... 57, 59

erosive effect 62

height 87, 58, 69, 64. 79

progress 67

sources of Information - 57

velocity 57. 59. 63, 79

Wave on October 27, 1938, causes 71, 72, 78, 74, 79

erosive effect 70

height 68. 69, 70. 71. 73, 79

velocity 68, 70. 7 1

Wave In 1853 or 1854, age 77

cause 77

Wave* In other parts of the world 66, 67

Wlegel, R. L„ quoted ... ............. 63, 64. 65

Yakutat. Alaska 63. 54, 59. 75

Yakutat Bay 55, 67. 73, 75

Ulrich, II. G., account by

57, 58 Zones of denudation

54, 60, 62, 64, 05 ; pi. 8

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Early Cretaceous
(Albian) Ammonites
From the Chitina
Valley and Talkeetna
Mountains, Alaska

By RALPH W. 1MLAY

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROEESSIONAL PAPER 354-D

The Early Cretaceous ( Albian ) ammonites in
southern Alaska have strong affinities with
those in California and Oregon but are in part
oj Boreal and Eurasian origin

UNITED STATES GOVERNMENT PRINTING

OFFICE, WASHINGTON

1960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington 25, D.C. - Price 50 cents (paper cover)

CONTEXTS

Pa*r

Abstract 87

Introduction. 87

Biologic analysis.. 87

Stratigraphic summary 88

Talkcctna Mountains .... 88

Cliitina Valley ..... 88

Ammonite faunules an<l correlations 80

Letonleile x modes / iji and PutosigeUa faunulc 80

Moffitiles robust ua and Leconteite a deansi faunulc . 91

Ammonite faunules and correlations — Continued Pxto

Brewerieeras breieeri and B. cf. li. hulenense faunule.. 91

Freboldieeras singulars faunulc ........ 92

Other Albinn faunules 93

Comparisons with other faunas 93

Geographic distribution 93

Summary of results ...... 93

Systematic descriptions ..... 97

References..... 111

Index 113

ILLUSTRATIONS

| Plain follow Imlrx)

PLATE 11. Phyllopachyceras. Culliphytloccras, Anagaudryceras, I'aldcdorsella?, and Hypophylloceras.

12. Calliioniccras, Kossnialella, Plychoecras, und Telragoniles.

13. llfoffitites.

14. Beudanticerax, Moffitites, and Freboldieeras.

15. Kennicotlia.

16. Putoxia and Beudanticerax.

17. Desmoceras ? and Brewerieeras.

18. Parasilesiles, Hulenites, Arethopliles"!, and Lemuroeeras.

19. Lccontcites, Aucellina, Puxosigella, and Cieonicera*.

Pass

Figure 21. Correlation of the Albian faunas of the Chitina V'alley and Talkeetna Mountains 0(1

22. Index map of the principal areas 04

23. Index map showing Albinn localities in the Chitina Valley .... 95

24. Index map showing Albian localities in the Talkeetna Mountains 97

TABLES

Pose

Table I. Ammonite genera in the Albian beds of the Chitina Valley. Talkeetna Mountains, Alaska, showing biological

relationships and relative numbers available for study 88

2. Localities at which ammonites were collected from the Albian strata of the Chitina Valley and Talkeetna Moun-

tains 9P>

3. Geographic distribution of early und middle Albian ammonites from the Chitina Valley and Talkeetna Moun-

tains, Alaska 08

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

EARLY CRETACEOUS (ALBIAN) AMMONITES FROM THE CHITINA VALLEY AND

TALKEETNA MOUNTAINS, ALASKA

By Rammi \V. Imi.ay

ABSTRACT

The Early Cretaceous (Alblan) ammonites of the Chitina
Valley and Talkeelnn Mount a Ins, Alaska, belong to four fnu-
miles ranging in age from early to early middle Albion.

The lowest fnunule In the Chit inn Valley is characterized by
Lcrnntcite* modest us (Anderson) and by *]>ecies of Pnsosigclla
that iH'rmit a close correlation with the Leroiitritex leetmlei
zone of California and Oregon and hence with the early Albion
•if Eurasia. Moffltitrs crassus Imlny. n. sp., also may be char-
acteristic of this fnunule.

The next higher fnunule in the Chilian Valley Is characterized
by it offltitrs robust us Imlny and Lcronteitvs tleansi (Whit-
eaves). It Is probably only slightly younger than the Txcron-
(rile* Iccontci zone of California and Oregon. The next higher
Albion fnunule In the Chit inn Valley is characterized by a
coarsely ribbed variant of Rrnrrrirrrnx hrctrrrl (Gabb) that
suggests approximate correlation with the Rmreriecras hulru-
ruse zone in California. An early Albinn age for this fnunule
is indicated by the ammonites Vtihleitorsvlla. Parasilrsites, and
suhgen us S u hareth opli I vs.

In the Talkeetna Mountains the only Albiuu representative
is the Frcbnltticrra * singularc fnunule. which Is characterized
by excellently preserved s|ieciinens of Rruilanticcra* glahrum
( Whitenves). Frchohlicrras siugulare Imlny. and Lem it rover ax
taltccctnanum Imlny, n. sj>. These are either identical with or
closely related to ammonites in the western interior of Canada
beneath hods that contain OastropUtes. The fnunule is prob-
ably younger than the Lemuroreras hrlli zone of Canada and
the Urnrerieeras brcirert fnunule of the Chltlun Valley, but
the evidence Is not conclusive. If it is younger. Its age Is
probably early middle Alblan.

The Alblan ammonite faunnles of the Cliitinn Valley have a
provincial aspect owing to the presence of genera not yet found
outside the l’ndtic const of North America. These include
it o /fit it ex, Kenuirottia, Rrnrrrireras. iA-eonteitrs, Puzosigella.
Ifulruitrx. and Parasilesitrs. A marine connection with the
boreal province through Canada or Alaska is Indicated, how-
ever. by the presence of such ammonites ns Lemuroreras (Sub-
arcthoptltes) and Callizonicrras, la addition the faunnles in-
clude many genera that are distributed nearly worldwide, or
that do not characterize any particular province. The Albinn
ammonites of the Talkeetna Mountains likewise exhibit a
provincial asjiect. lint in contrast to those from the Chltlnn
Valley, the relationships are strong with the western Interior of
Canada and with northern Alaska.

These faunal relationships Imply that the Albinn sea that
covered southern Alaska had broad connections with sens In
the western interior of the continent, in California and Oregon,
and in Asia.

INTRODUCTION

This study of the Early Cretaceous (Albian) am-
monites of the. Chitina Valley and Talkeetna Moun-
tains in the southeastern part of the main body of
Alaska is based on collections made by members of the
Geological Survey since 1 SOD. Thanks are due to Leo
G. Ilertlein and Dallas G. Hanna, of the California
Academy of Sciences in San Francisco, for the privi-
lege of examining the type specimens of certain Albian
ammonites. Correlations with Albinn lteds in Cali-
fornia were influenced by discussions with Michael
Murphy of the University of California at Riverside.
Some notes on the Cretaceous of the Chitina Valley
prepared by Don J. Miller, of the U.S. Geological Sur-
vey, were very useful in determining the stratigraphic
distribution of the Albian faunnles.

The Albian ammonites of the Chitina Valley and
Talkeetna Mountains are of exceptional interest be-
cause they are highly varied, and well preserved and
represent an association of ammonites that occur else-
where in distinct faunal provinces and are associated
with plants that paleobotanists maintain are of Juras-
sic age. Description of the ammonites is justified,
therefore, as documentation of their Albian age and
t hat of the associated plants, as an aid in geologic
mapping, and as a means of interpreting local geo-
logic history in terms of events elsewhere. The fact
that the ammonite faunnles are derived from various
provinces should prove useful in making interregional
and intercontinental correlations.

BIOLOGIC ANALYSIS

The Albian ammonites from the Chitina Valley and
Talkeetna Mountains include 37!) sjiecimens, of which
308 are specifically identified and 61 are compared to

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

described species. Among these the Phylloceratidae
are represented by 28, t he Tetragon it idae by 40, the
Ptychoceratidae by 2, the Desmoceratidae by 205, the
Silesitidae by 5, the Kossnuiticeratidae bv 4, and tlie
Hoplitidae by 95. The distribution of these specimens
by genera, subfamilies, and families is shown in table 1.

The table shows that the Desmoceratidae is the domi-
nant family as regards individuals, species, and genera.
It is characterized by the presence of such genera as
Mofjitltes, Freboldirerax . Kennirottia, and Bretren-
ccras, which have not lieen recorded outside the Pa-
cific const of North America. It includes, however,
such Old World genera as Valdedorxel/a, CalUzoni-
rerax. Puzos in. and Desmocern*. The species of Jieu-
dantircrax present have certain peculiarities that dis-
tinguish them from European s|>eries, hut are judged
not to lie of sufficient imjmrtnnee to warrant generic
differentiation.

Tabi.k I. — Ammonite genera in the Albion beds of the Chitina
y alley anil Talkeetna Mountains, Alaska, showing biological
relationships anil relative numbers available for slmly

Family

Subfamily

Genus

8|WCi>

men*

(’alHphyllomniimte...

/ fyiJoptiylloctraA

i'allifAytloeerar

Kmsmatidlliiiw

KtitAinrt/fUa

TtlraQouUes . .

OrMtiucvralidiM' . .

('alli:onkero»

Staffilite*

Freboltiicertn

I\en»ia\ttia

Fuzotto

JWudantlctrnr

t Cr.tni;(fefQ*)

lireuerictras.. . .

StlraltbUr

I*nra.iile liter .

otlla

I.tconteile*

I.tmuroetrtu (Stitt-

Qrcthoi*iitn) .

A retho fitter ?

Next in importance is the family Hoplitidae in
which the genera PuzoxujcUa and Leconteites dominate
in individuals and in species. These genera have not.
yet been reported elsewhere than the Pacific const of
North America. Of particular importance is the pres-
ence of typical representatives of the genera Cleon i-
rents and Lemurocerax. There are also, two specimens
belonging to Suburrthojditcx Casey (1954, p. Ill)
which is herein considered to be a subgenus of Lnnttro-
rrrax.

The families Phylloceratidae and Tetragonitidae are
of comparatively minor importance, ami the other
families in table 1 are represented only by single species
and a few specimens. It is interesting, however, that

Paraxilexitex and Huleniten have not been recorded out-
side the Pacific const of North America.

The absence of PxeudoleymrrieUa Casey (1957, p.
35; Whiteaves, 1893b, p. 444, pi. 7, figs. 2, 2n, b), which
occurs in early Albian lieds in the Queen Charlotte
Islands, ns well as the absence of Dourilleiceras, which
is common in California, possibly reflects insufficient
collecting.

STRATIGRAPHIC SUMMARY

TALKEETNA MOUNTAINS

Albian ammonites have l»een found in the Talkeetna
Mountains at only two places, one near the head of
Hilly Creek and the other near the head of Flume
Creek. They occur in concretions in the basal 125
feet of a shale and siltstone unit above 150 feet of
sandstone that contains coaly lieds of unknown age.
This sandstone overlies 550 feet of sandstone of Va-
langinian age that overlies the Nelchina limestone of
Valanginian age. From the siltstone 250 feet above
the concretions, sjieeimens of Inoccramux of Late Cre-
taceous age have been obtained. There is a possibility
that the concretions have lieen reworked from older
beds (Arthur Grants, written communication, Dec. 29,
1958) . Nevertheless, the presence of Albian ammonites,
even locally, in the Talkeetna Mountains suggests that
Albian beds once existed nearby and may now exist in
the subsurface of the Copper River basin east of the
mountains.

CHITINA VALLEY

Albian beds in the Chitina Valley have lieen identi-
fied only in the up|>er (eastern) 50 to 60 miles of the
valley east of the Kuskulana River. The main areas
of outcrop, from west to east, occur near Kuskulana
Pass, along Folilin and Hear Creeks west of Kenni-
cott Glacier, near the head of McCarthy Creek, and
near the foot of Nizina Glacier. Several other areas of
outcrop occur from 25 to 35 miles south of the Nizina
Glacier near the headwaters of Young Creek and near
the mouth of Canyon Creek. The extent of outcrop
in most of these areas is not known. However, the
numerous collections obtained near Kuskulana Pass
and the creeks immediately to the west are all of Al-
bian age except for some fossils obtained 5,800 feet S.
39° E. of the mouth of Slatka Creek (Mes. loc. 8939)
that are probably of Late Cretaceous age. In the
area along Fohlin and Hear Creeks, all the Albian fos-
sils were obtained near or north of Hear Creek and its
east -northeast project ion.

'Phe total thickness of the Albian lieds in the Chitina
Valley is not known, but it is probably only a few
hundred feet. In the section measured by Moflit (1938,

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETN'A MOUNTAINS

p. 71) on Fourth of July Creek west of Xennicott
Glacier, only the lower 150 to 250 feet of massive brown
sandstone ami crumbly gray shale have furnished
Albian fossils. The thickness of Albian beds at the
head of McCarthy Creek must be slight also because
that area has furnished many collections of Late Juras-
sic (Oxfordian to Kimmeridginn) age (USGS Mes.
Iocs. 11373, 11374, 11376, 11378, 11380, 14032, 14034,
14035, 14495-14407) and Karly Cretaceous (Valan-
ginian) age (I’SOS Mes. Iocs. 2172, 2209, 11375, 11377,
14031, 14500-14502), but. only one collection (USGS
Mes. loc. 6313) of Albian age. That collection was
from a sandstone, but the preservation of the fossils
indicates that they were obtained from a concretion
in the sandstone. A collection at the bend of Young
Creek (Mes. loc. 9492), obtained from concretions in
brown sandstone, is younger than any of those ob-
tained on Fohlin Creek, Bear Creek, or near Kusku-
lana Pass, but the thickness of the stratigraphic unit
involved is not known.

The 352 find of sandstone and shale exposed at the
base of the Cretaceous near the mouth of Canyon
Creek (Moflit, 1938, p. 73) (Mes. Iocs. 9481, 94*85-
9487) contains fossils of late Albian to Cenomanian
ages, according to Tatsuro Matsumoto (1959, p. 85,
86), and are therefore appreciably younger than the
early Albian licds exposed in a similar appearing se-
quence at the base of the Cretaceous on Fourth of July
Creek. Interestingly, Mesozoic locality 9489, about 3
miles west of the mouth of Canyon Creek, contains
early Albian fossils identical with those near the base
of the Cretaceous on Fourth of July, Bear, and Fohlin
Creeks. Judging from published illustrations (Moflit,
1938, pi. 2: Moflit and Overlieck, 1918, fig. 2, on p. 27,
and pi. 3), Mesozoic locality 9489 should be somewhat
lower stratigraphicallv than locality 9487 at the mouth
of Canyon Creek along the same !>elt of outcrops, but
the stratigraphic interval lietween these localities
cannot be measured from the map. These occurrences
suggest, however, that the basal laals of the Cretaceous
sequence in the Chit inn Valley are of different ages
from place to place and that the Albian part of the
sequence is not very thick.

AMMONITE FAUNULES AND CORRELATIONS

LECONTEITES MODESTUS AND PUZOSIGELLA
FAUNULE

This faunule (fig. 21) is represented in the Chitina
Valley near Bear, Fohlin, and Fourth of July Creeks
at USGS Mesozoic localities 8877, 9971, 11389, and
14468 by the ammonites Lcconteitex modextus (Ander-
son), Puzoxigella cf. I‘. rogerxi (Hall and Ambrose),
P. cf. P. perrinxmithi (Anderson), P. cf. P. tajfi

(Anderson), ami Anagaudrycerax aurarium (Ander-
son). The faunule may l>e represented, also, by Moffiti-
tex craxxux Imlay, n. sp., obtained 1 mile north of Bear
Creek at USGS Mesozoic locality 14487 and 3 Vo miles
southeast of Kuskulann Pass at USGS Mesozoic lo-
cality 14477.

These ammonites are usually associated with many
specimens of the pelecypod Aucellina (Moflit, 1938,
pi. 10, figs. 4, 5), which genus in reports dealing with
the Chitina Valley has generally l>een compared with
"Aurelia” pallaxi (Keyserling), or '•'Aurelia” eraxxi-
eollis (Keyserling) (Martin, 1926, p. 336, 347, 348;
Moflit, 1938, table facing p. 80). It includes all speci-
mens previously assigned to “Aurelia' except those
from the Late Jurassic and Early Cretaceous (Va-
langinian) localities listed herein under the heading
“St ratigraphic summary.*’

The localities listed under the Leconteites modextus
faunule are all near the contact of Cretaceous with
Triassic rocks and, judging from Moffit’s map (1938,
pi. 2), are distinctly lower stratigraphic-ally than most
of those of the succeeding faunule typified by .1 foffiti-
tes robustus Imlay. At a few places, however, the
fossils of one faunule were found near those of the
other, as at USGS Mesozoic localities 8877 and 8878.
This is not surprising considering that the total thick-
ness of lx*ds involved in both faunules is not. more
than 300 feet in most places (Moflit, 1938, p. 71, 78).

The Inals containing Teconteite x modextus (Ander-
son) and Puzoxigella spp. may lie correlated with the
Lcconteitex leeontei zone (Murphy, 1956, p. 2118, fig.
6) in California and Oregon liecause of the presence
of the genera Lcconteitex and Puzoxigella and of the
s|>ecies Lcconteitex modextus (Anderson). Also, the
presence of Anagaudrycerax aurarium (Anderson) is
normal in that zone, although it ranges higher in Cali-
fornia into the zone of ]{ retcericerux hulenenxe.

The age of the Lcconteitex leeontei zone is either
early or early middle Albian as shown by the presence
of the ammonite Douril/eicerax, which in Europe
ranges from the upper part of the Leymeriella tarde-
f areata zone into the middle of the llo/ditex dentatus
zone (Spnth, 1930, p. 60-65; Collignon, 1949, p. 1 10—
114; Breistroffer, 1947, p. 27, 28). An early Albian
age for the Lcconteitex leeontei zone is favored, how-
ever, by the presence of Silexitcx. which normally oc-
curs in IhmIs older than Albian, and by the presence of
Douvilleiceras in the next two overlying zones, which
may l»e correlated with the upper part of the range
of the genus in Enro|»e. The presence of Anagaudry-
ecrax and Tetragonitex indicates an age not older than
Albian.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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Kiel it r. 21. — Correlation of tin* Alhinti fauna* of the Chltlun Valley and Talkeetna Mountain*.

CRETACEOUS AMMONITES FROM CH1TINA VALLEY AND TALKEETNA MOUNTAINS

MOFFITITES ROBUSTUS AND LECONTEITES DEANSI
FAUNULE

This fan mile (fig. 21) is represented in the Chitina
Valley at many localities along Hear and Fohlin Creeks
(USGS Mes. loo. 2147, 2191, 2201, 9872, 8873, 8875,
8876, 8878, 8880, 9966, 9967, 9967a, 9972, 9973, 9976,
9978, 14471, 14484. 14485), and at single localities along
Fourth of July Creek (USGS Mes. loc. 14467), Trail
(’reek (USGS Mes. loo. 9950), and 3 miles west of the
mouth of Canyon (’reek (USGS Mes. loc. 9489). The
most common ammonites are MoffUitex robuxtu * Imlay,
Kennicottia bifurcnta Imlay, Leconteitex deanxi
(Whiteaves), L. craxxicoxtatux Imlay, n. sp., and .1 n -
gaudrycerax aurarium (Anderson). Somewhat less
common are Phyllopachycerax cf. P. xhaxtalenxe (An-
derson), Calliph yllocerax of. C. alderxoni (Anderson),
Ptychocerax cf. P. lucre (Gabb), Callizonieerax (Wol-
lemannicerax) alaxkanum Imlay, n. sp., C. (W.) foh-
lincnxe Imlay, n. sp., Kennicottia rugoxa Imlay, n. sp.,
Puzoxin sp., and Leconteitex atf. L. deanxi (Whiteaves).
These ammonites are associated with the pelecypod Am-
cclfina (pi. 19, figs. 28-32) which locally occurs in great
numbers and lias l>ecn obtained at many more locali-
ties than the ammonites.

The Moffititex robuxtux fannule is of early Albian
age — only a little younger than the underlying fannule
containing Leconteitex modextux (Anderson) and Puzo-
sigella. This is indicated by tiie dose stratigraphic
association of the faunules and by the presence in both
of the genus Leconteitex. which in California has been
found only in the Leconteitex lecontei zone of early
Albian age. Similarly, the presence of CaUizonicerax
(Wolletnannicerox) is excellent evidence that the Moffi-
titex robuxtux fannule is not younger than early Albian
(Wright, 1957, p. 1,363).

The Moffititex robuxtux fannule is not correlated with
either the Leconteitex lecontei zone or the overlying
Brcwericerax hulenenxe. zone in California (Murphy,
1956, p. 2118) because the only s|>ecies in common with
those zones is Anagaudryeerax aurarium (Anderson)
and l>ecnuse those zones may la* correlated resjjectively
with tlie Leconteitex modextux fannule and the lire ice ni-
cer ox breweri fannule of the Chitina Valley. Both
stratigraphically and faunally, therefore, the Moffi-
titex robuxtux fannule appears to occupy a position in-
termediate between the California zones in question.
Such a position is not in conflict with recent studies in
California. Insertion of the zonal map prepared by
Murphy (1956, fig. 5 on p. 2109) for the Cottonwood
area near Ono, Calif., shows that there is ample space
stratigraphically for another fannule zone lietween the
Leconteitex lecontei and 11 re me rice rax hulencnxe zones.

534 624 O — 80 2

BREWERICERAS BREWERI AND B. CF. B. HULENENSE
FAUNULE

This fannule is represented in the upper part of the
Chitina Valley at USGS Mesozoic localities 9480 and
9492 near the head of Young Creek, at USGS Mesozoic
locality 14514 near the foot of Nizina Glacier, and
probably at USGS Mesozoic locality 6313 near the
head of McCarthy Creek. The fossils at localities 9492
and 6313 were obtained from concretions in sandstone,
but the. characteristics of the beds at the other locali-
ties is not known. As all these localities are many
miles from the localities that furnished Leconteitex and
Molfititex. the thickness of the stratigraphic unit in-
volved is not known.

The fossils in the fannule characterized by Breweri-
cerax breweri (Gabb) are listed by localities as follows:

l‘li nU'iinwh iirernx rli il inn mini Imlay. n. sp 14492

// ypoph yllocerax cf. H. calif nrnicuni (Anderson) 9402

Calliyihyllnccra* niiinanum Imlay. n. sp 9492

Anagaudryeerax sp. Indet 6818

Koxxiuatclln cayyxi Imlay. n. sp 9-492. I45I-4

Tclragonilcx all. T. tinwthcanux < Pictet ) 9492

I'alilctlorxclla ? irhitcnrcxi Imlay. n. sp 9492

Pmoxia alnxkann Imlay. n. sp 9492

Itrcirrrircrax breircri (Gabb) .... 9492

cf. R. hulenenxe l Anderson) 6.113. 9492, 14514

Dcxinoccrax sp. juv 9492

I'araxilcxitcx Inilliilux Imlay, n. sp 9492

irrcyularix Inday. n. sp 9492

II iilcnitcx cf. It. rccxhlcl ) Anderson ) 9480, 9492

Ctvtiniecrvx orerbecki Imlay, n. sp 9492

l.cntiirticcrax ( tin ba rclh opli tex) a ft. L. belli McLearn 9492

Arcthoylilc*? sp ... 9492

The only abundant ammonites among those listed
are Puzoxin alaxkana Inday, n. sp., Call! phylloce rax
nizinanum Imlay, n. sp., Brewericerus breweri (Gabb),
and B. cf. B. hulencnxe (Anderson). All other species
are represented by five specimens or less. Associated
with these ammonites are many other mollusks (Mofiit,
1018, p. 40), of which the most significant stratigra-
phically are small specimens of Inoccramux that re-
semble immature specimens of /. eomancheanus
Cragin (equals /. anglieux Woods). Also, of strati-
graphic significance is the absence of the pelecypod
Aucellina. which is abundant in the older beds con-
taining Leconteitex ami Moffitites.

The l>cds in the Chitina Valley that contain Breweri-
cerax breweri (Gabb) and B. cf. />. hulenenxe. (Ander-
son) are considered to la* approximately equivalent, to
the zone of B. hulenenxe in northern California (Mur-
phy, 1056, p. 2118, fig. 6) Itecause they both contain
the same coarsely riblied variant of />. breweri (Gabb)
that was illustrated by Whiteaves (1876, p. 21, pi. 1,
figs. 2, 2a, 3, 3a) from the Queen Charlotte Islands.
Also, the specimens herein compared to //. hulenenxe
(Anderson) are probably immature examples of that

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

S|>eeies rather than of B. hay deni (Gabb). Otherwise
the Alaskan Breicericera x brewer! faunule differs from
tin* ammonites in the B. hulencnxe. zone in California
by the absence of the genus Pourilleicerax and the
presence of the genera Valdedorxella. Paraxilexitex.
Ilulenitex. Clean terras, and Lemurocerax (Subarcfho-
plitex).

The Brexrericera x hulencnxe zone in California may
l>e correlated with the I) our tile ice rax mammillatum
zone in Eurojie on the basis of containing an abun-
dance of Dourilleicerax and of 1 icing in the middle of
the local range of Dourilleicerax. Similarly the un-
derlying Teeonteitex lecontei zone may be correlated
with the lowest occurrence of Dourilleicerax in Europe
in the upper part of the Leymeriella tardefurcata zone.
If these correlations ait* correct, the age of the B.
hulencnxe zone should be late early Alhian, according
to the classification used by Wright (1957, p. L128)
and Breistroffer (1017, p. 51, 53), or early middle
Albina, according to the classification used by Spath
(1041, p. 668).

Concerning the age of the beds in Alaska that con-
tain B re tee rice rax brewer! (Gabb), an early rather
than middle Alhian age is indicated by the presence of
such genera as Valdedorxella and I.emuroccrax (Sub-
arcthoplitex). Of these, Valdedorxella has not been
found above the lower Albian in Europe; Paraxilcxitex
belongs in a family that is not known above the lower
Albian ; and the suhgenus .S' ubarctho pi it ex occurs in
northern Alaska al>out (i(H> feet lielow the lowest known
occurrence of C/eonicerax . which ranges through more
than 2,500 feet of strata (Imlny, 1060).

FREBOLDICERAS SINGUXARE FAUNUXE

This faunule is represented in the Talkeetna Moun-
tains by the ammonites Tetragonitex sp., Freboldicerax
xirxgxtlare Imlay, Beudanticeras glabrum (Whiteaves),
B. (Grantzicerax) mult iconxtrict urn Imlay; and Le-
in a rare rax talkeetna nttm Imlay, n. sp. The faunule is
of unusual interest liecause of the excellent preserva-
tion of the s|>eciinens, l>ecause its component s|>ecies
show close affinities with Albian species in the western
interior of Canada and in India, and because, its genera
and s|H*cies have no known affinities with the Albian
ammonites of California or Oregon, although they
occur in the same marine basin as the Albian ammonites
of the Chitina Valley that are closely related to am-
monites in California and Oregon.

The age of the ammonite faunule in question from
the Talkeetna Mountains is either early Albian or early
middle Albian on the basis of comparisons with similar
ammonites in the western interior of Canada. The
presence of Bcudanticcrax glabrum (Whiteaves) indi-
cates a correlation with Albian Inals in Canada below

the lowest occurrence of the ammonite Gaxtroplites in
the Harmon shale member of the Peace River forma-
tion (Henderson, 1954, p. 2285, 2286: Stelck and
others, 1956, p. 10, 12). The resemblance of Fre-
boldicerax xingulare Imlay to “ Lemvrorerax " irenenxe
Mcljearn ( 1945, pi. 5, fig. 5: 1948, p. 2) from the upper
part of the Moosebar formation of British Columbia
(Stelck and others, 1956, p. 10) suggests an age slightly
younger than that of Lemurocerax ( Subarcthoplitex)
belli McLearn (1945, pi. 3, figs. 17, 18; 1948, p. 2) from
the Clearwater formation and the upper part of the
I/oon River formation (Mclx*arn and Kindle, 1950,
p. 86, 93). However, the resemblance of Lemurocerax
talkeefnanum Imlay, n. sp., to Lemurocerax cf. L. indi-
cium Spath ( McLearn, 1945, pi. 5, fig. 4) from the
lower part of the Ijoon River formation (Stelck and
others, 1956, p. 6, 11, 14) suggests an age slightly older
than that of Lemurocerax belli McLearn.

The fact that Lemurocerax talkeefnanum Imlay, n.
sp., is remarkably similar to L. indicum (Spath) (1933,
p. 801, pi. 129, fig. 5) from India and Madagascar
(Collingnon, 1949, p. 68, 69, pi. 12, figs. 2, 2a, b, pi. 14,
fig. 2) suggests that it is of nearly the same age as that
species and that the Freboldicerax xingulare faunule
may lie correlated with the Old World Dourilleicerax
mammillatum zone. As just discussed, however, corre-
lation with that zone seems reasonable, also, for the
Brexrericerax hulencnxe zone in California and for the
B. bremeri faunule in the Chit inn Valley which have
an entirely different ammonite assemblage than the
faunule in the Talkeetna Mountains. This difference
is especially significant for correlation purposes con-
sidering that the Albian lieds of the Talkeetna Moun-
tains and of the Chitina Valley were deposited in the
same basin and, therefore, that the ammonites in those
beds should not differ greatly provided they arc of the
same age.

Therefore, the Albian fossils from the Talkeetna
Mountains are either slightly younger or slightly older
than the Breircricerax brewer! faunule in the Chitina
Valley. The matter cannot la* settled definitely on the
basis of available evidence, but a younger age is sug-
gested by the fact that in northern Alaska the lieds con-
taining Lemurocerax belli Mcljearn are underlain by
beds containing Albian ammonites that are consid-
erably different than those in the Talkeetna Mountains.
Accordingly the Freboldicerax xingulare faunule is
probably younger than the I.emuroccrax belli zone of
Canada and northern Alaska and should lie sought in
the upjicr part of the Moosebar formation and in the
Gates formation of British Columbia and in the No-
tikewin memlxr of the Peace River formation of Al-
berta. Such a correlation would agree with the general

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALK E ETNA MOUNTAINS

resemblance of F rebold ice rus xingulure Imlay to “Le-
in u row rax'' ireneme McLearn.

OTHER ALBIAN FAUNULES

Some fossil collections of late Albian to Cenomanian
apes liave been obtained from the valley of the Xizina
Glacier (I'SGS Mes. Iocs. 140158, 14040, 14511, 14515)
and aliout .'50 miles south-southeast of that planer in
an area northwest of Gibraltar Hill (I'SGS Mes. Iocs.
9481, 9485-9487). Most of the fossils were considered
to Ik* of Albian ape by Imlay and Iteeside (1954, p.
230), but recent studies by Matsumoto (1959, p. 85,
80) show that USGS Mesozoic locality 9481 contains
fossils of probable Cenomanian ape and that the other
localities contain lonp-ranpinp species that could be
of late Albian or of Cenomanian ape. A definite ape
determination must await additional collect inp. Con-
siderinp these ape limitations, it is interestinp that
plant fossils obtained from I’SGS Mesozoic localities
9481 and 948(5 and from many localities of early to
middle Albian ape in the Chitina Valley have lieen
identified by F. II. Knowlton as definitely Late Juras-
sic (Moflit and Overlieck, 1918, p. 42, 44 : Martin, 1929,
p. :5:5(5-:54f>; Moflit, 19:48, p. 88).

COMPARISONS WITH OTHER FAUNAS

The Albian ammonites from the Chitina Valley be-
lotip in the same faunal province as the Albian am-
monites of California and Orepon as shown by the
presence of the genera fi merrier rax, Ilulenitex. Fuzoxi-
r/ella, and Leconteitex. However, some kind of faunal
connection with the western interior of Canada and
with northern Alaska is shown by the presence of
Lem u row rax ( Subvert ho/>/if ex) in association with
/Imreriwrax. Also the presence of Callizonicerax,
known elsewhere only from Greenland and northwest
Kurope, suppests some kind of connection throuph
Canada or northern Alaska with the boreal province.
The penera Moffititex and Kennicottia have not yet
been reported from California or Orepon but are pres-
ent in I’.S. Geolopical Survey collections from the
Queen Charlotte Islands and may lie exjiected farther
south. Most of the other penera are widely distributed
in many parts of the world.

The few Albian ammonites from the Talkeetna
Mountains in contrast with those from the Chitina
Valley lielonp in the same faunal province as the Al-
bian ammonites of the western interior of Canada ami
of northern Alaska and have not yet lieen found in
California ami Orepon. This is shown by the presence
of Iteudantiwra* glubrum (Whiteaves), which is com-
mon in the western interior of Canada, and of s|iecies
of Ilrudantircnix. F rebold iwnis. and 1 -emu row rax that

are closely similar to Canadian species. Such a rela-
tionship is surprisinp because any Albian lieds in or
near the Talkeetna Mountains must have been de-
posited in the same marine sedimentary basin as the
Albian lieds of the Chitina Valley. These facts mean
either that there was some mixinp of the Albian faunas
of the interior repion, which are of boreal oripin, with
those of the Pacific coast durinp Albian time or that
the faunas were actually not distinct. In this connec-
tion the presence of a species of Lv mu rove ran in the
Talkeetna Mountains similar to L. indirum (Spath)
from India and Madapascar (Spath, 19:5:$, pi. 128,
figs. 4a, b, 5a, b; Collipnon, 1949, pi. 1*2, lips. 2, 2a, b,
pi. 14, fips. 2) and to a sjiecies from the western in-
terior of Canada (McLearn, 1945, pi. 5, fip. 4) suppests
that the Albian ammonite faunnles of the western in-
terior of Canada and of northern Alaska may have had
a much wider distribution than now realized.

In summation, the Albian ammonite assemblage in
southern Alaska is predominantly related to the Albian
ammonite assemblage in California and Orepon, but
includes some penera and sjiecies that are boreal in
oripin, and others that occur in Albian la*ds in many
parts of the world.

GEOGRAPHIC DISTRIBUTION

The occurrence by area and locality of the 45 species
descrilied in this report is indicated in table 3. The
position of the two known areas of lower to middle
Albian rocks in the southeastern part of the main
body of Alaska is shown in figure 22, and the general
position of each locality is shown in figures 23 and 24.
The positions of such localities as 2147, 2173, 2191,
2201, and 9313 may lie in error by a mile or more lie-
cause of inadequate field descriptions. Descriptions
of the individual localities are given in table 2. This
list does not include any localities mentioned in the text
under such ages as Late Jurrassic, Early Cretaceous
( Vnlnnginian), or late Albian to Cenomanian. The
description of such localities may lie found in U.S.
Geolopical Survey Bulletin 894 on pages 83-88.

SUMMARY OF RESULTS

The Early Cretaceous (Albian) ammonites from the
Talkeetna Mountains and the upper pail of the Chitina
Valley discussed herein are well preserved and highly
varied. They include 24 penera and 45 sjieeies. Of
these S|iecies 18 are descrilied as new. Of the 24 penera,
4 were descrilied as new in a preliminary paper (Im-
lay, 1959) published during the couiNe of this study.

Among the Albian ammonites the family Desmocera-
tidae is dominant in numliere, penera, and species. It
is characterized by the penera .1/ offi fifes. Freboldicrrax,

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

PlaOBC 22. — Index iimp of the main oroaR of Albion foKHlli* in ihi* Kouthwistiwn part of the main body of Alaska.

Kennirottia, and B re we rice rax. which have not been
recorded outside of the Pacific coast of North America.
It includes, also, the Old World genera Cullizonirerax ,
Puzoxia. Beudantirerax. and probably V aldcdorxclla
and Dexmoceivx. Next in importance among the Al-
bian ammonites is the family Ho/dilidae. It is char-
acterized by the genera Leconteitex and Puzoxigella ,
which have l>een found to date only on the Pacific coast
of North America, but includes the widely distributed
genera Cleonicerax and Lemurorera*. Of considerable
lesser importance arc the Phylloceratidae and Tetra-
gonitidae. The Ptychoceratidae, Silesitidae. and I\oss-
maticeratidae are represented by only a few specimens.

The Albian beds include four ammonite faunules.
In the Chit ina Valley the faunules, from oldest to
youngest, are characterized by 1 , I. econteitex mod extux
(Anderson) and Puzoxige.lla spp. ; 2, Moffititex robuxtvx
I in lay and Leronteitex deanxi (Whiteaves): •'},

B reiver ire rax breireri (Gabb) and B. cf. B. huienenxe
(Anderson). In the Talkeetna Mountains Occurs a
fourth faunule characterized by P rebold icerax singu-
lure Imlay. This faunule is probably younger than
the other faunules, but the evidence is not conclusive.

The two lower faunules are associated with the pelecy-
pod A nee II inn.

The faunule characterized by Leconte itex m odextux
am\ Puzoxigelhi spp. is correlated with the Leconteitex
Iccontei zone in California and Oregon and is of early
Albian age.

The faunule characterized by Moffititex robuxtux Im-
lay and Leronteitex deanxi (Whiteaves) is considered
to lie intermediate in age lietween the Leconteitex le-
rontei zone and the Brewericernx huienenxe zone in
California. An age not younger than earlier Albian is
indicated by the presence of the genus Callizoniccrax.

The faunule characterized by Breirericerax breweri
(Gabb) and B. cf. B. huienenxe (Anderson) is ap-
proximately equivalent to the Breirericerax huienenxe
zone in California because it contains the coarsely
ribbed variant of Bretcericcrnx breweri (Gabb) iden-
tical with that in the B. huienenxe zone. The faunule
in the ('hit ina Valley differs in other respects, how-
ever, and may not be an exact equivalent. Its age.
judging by the presence of the ammonites Valdcdor-
xe/lut, Paruxilexitex. and Lcmuroccrax (Subarctho-
fdites) is not younger than early Albian.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

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Fieri!*: S3. — Index roup shewing Alblan lucnlltle* In the Cbltinn Valley.

96 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Tabi.e 2. — Localities at which ammonites were collected from the Albion strata of the Chitina Valley and the Talkeelna Mountains

Locality on
Ars. 2 and 3

Geological Sur-
vey Mesozoic
localities

Collectors' field

No*.

Colleclor. year ot collection?, description of locality, and lithologic fcaturra

9950

Moffit, F. It., 1916. On west side of Trail Creek at altitude of 3,500 ft, Chitina Valley.

14477

AM-F14

Moffit, F. H., 1928. Near head of Chokosna River, 1 tnilc up southern tributary that joins
river at the Kuskulana Trail, Chitina Valiev.

8873

Martin, G. C., and Overheck, R, M., 1914. East bank of Fohlin Creek, 4,900 ft north of
mouth of Bear Creek, Chitina Valiev.

8875

Martin, G. C., and Overbeck, R. M., 1914. East bank of Fohlin Creek about 6,800 ft
north of Bear Creek, Chitina Valiev.

887(5

Martin, C». C., and Ovcrbeck, U. M. f 1914. East bank of Fohlin Creek 5,500 ft north of
Bear Creek, Chitina Valiev.

3 .

14484

28AM-F21

Moffit, F. H., 1928. Fohlin Creek 1 mile, north of Bear Creek. Near Mes. loc. 8873,
Chitinu Valiev.

14485

28AM- F22

Molfit, F. H., 1928. Fohlin Creek 100 vds north of Mes. loe. 14484, Chitina Valiev.

4 .

9971

MofTit, F. H., 191 6. At falls on first northern tributary of Bear Creek at altitude of 3,200
ft and a little more than 1 mile from Bear Creek, Chitina Valley.

4 . ....

14487

28AM-F24

Moffit, F. 11., 1928. First northern tributary of Bear Creek, 1 mile above its mouth, Chitina
Valiev.

14471

AM-F8

Moffit, F. if., 1928. About 1)4 miles north of Bear Creek and the same distance east of
Fohlin Creek, Chitina Valiev.

9970

Moffit. F. 11., 1916. On Fohlin Creek 125 ft above mouth of Bear Creek, Chitina Valiev.

9978

Moffit, F. 11., 1916. On Fohlin Creek, 1,300 ft upstream from Mes. loc. 9976, Chitina
Valley.

2147

Rohn, Oscar, 1899. Creek between Lakina River and Fohlin Creek between camps 11 and
12, Chitina Valiev.

2191

1048

Schrader, F. C., and Snencer, A. C., 1900. Creek tributary to the Lakina River half a mile
above crossing of old trail between Lakina and Kennicott Rivers, Chitina Valiev.

2201

Schrader, F. C., and Spencer, A. C., 1900. Old trail between Lakina and Kennicott Rivers,
Chitina Valiev.

7 . _

9966

Moffit, F. II., 1916. Half a mile above mouth of Bear Creek on first tributary from north,
Chitina Valley.

9967

Moffit, F. H., 1916. A little upstream from Mes. loc. 9966, Chitina Valiev.

9967a

Moffit, F. H., 1916. Float from Mes. loc. 9967, Chitina Valley.

Rohn, Oscar, 1899. Small canvon between camp 13 and the Kennicott Glacier, Chitina
Valiev.

8. -

2173

8. ...

9972

Molfit, F. 11., 1916. On Bear Creek at altitude of 2,850 ft about, half way from Fohlin
Creek to Fourth of July Pass. Soft, gray sandstone containing nodular masses, Chitina
Valiev.

9973

Moffit, F. IL, 1916. On Bear Creek near Mes. loc. 9972, Chitina Valley.

Martin, G. CL, and Overbeck, R. M., 1914. Float in Bear Creek about 254 miles above its
mouth, Chitina Valley.

8872

10. .

8877

Martin, G. C., and Overbeck, 1{. M., 1914. Bear Creek alnuit 3 miles above mouth, Chitina
Valiev.

10.

8878

Martin, G. C., and Overbeck, R. M., 1914. 100 yds above Mes. loc. 8877 on Bear Creek,

Chitina Valley.

11- ...

8880

Martin, G. C., and Overbeck, R. M., 1914. Bear Creek about 400 ft below summit of Fourth
of July Pass, Chitina Valiev.

14460

28AM-F4

Moffit, F. II., 1928. Northern tributary of Fourth of July Creek l}£ miles from its mouth,
Chitina Valiev.

12.

14467

28 AM- F4a

Moffit, F. II., 1928. Same as Mes. loc. 14466.

14468

28AM-F5

Moffit, F. II., 1928. Near Mes. loc. 14466, Chitina Valiev.

11389

Moffit, F. IL, 1922. On Fourth of July Creek 2 miles from Kennicott. Glacier, Chitina
Valiev.

6313

Moffit, F. I!., 1909. McCarthy Creek. Base of Kennicott formation.

14514

28AM-F51

Moffit, F. II., 1928. West side of Nizinn Glacier 1 mile from its lower end. Chitina Valiev.

1(5

9480

Molfit, F. 11., and Overbeck, R. M., 1915. Float from upper part of east branch of Young
Creek, Chitina Valley.

9492

Moflit, F. II., and Overheck, R. M., 1915. From concretions in sandstone in bluffs on
north side of Young (’reek west of big bend at altitude of 3,450 ft and half a mile above
foot of trail to the Chitina River, Chitina Valiev.

18 . .

9489

Moffit, F. 11. , and Overbook, R. M., 1915. From nodules in sandstone near south end of
trail from Chitina Valiev to Vouug Creek at altitude of 1,900 ft, Chitina Valiev.

19 . ..

24877

53A(!zl37

Grantz, A. and Fay, 1,. F„ 1953. Concretions in basal siltstone of the Matanuska formation
ovcrlving the Nclchina limestone near head of Bill v Creek, Talkootna Mts. (A-2) quad.,
lat 62“0I'40 , 4" N„ long I47°39'18" W., Tnlkuetna Mts.

Grantz, A.. 1954. Concretions in basal siltstone of the Matanuska formation overlying
the Nelchinn limestone near the head of Flume Creek. Talkeelna Mts. (A-2) quad,
hit 62W4I" N„ long !47°34'46" W., Talkectna Mts.

25320

54AGz53

25329

54AO.Z56L

Grantz, A., 1954. Concretions in basal siltstone of the Matanuska formation overlying
the Nelchina limestone near the head of Flume Creek. Talkectna Mts. (A-2) quad.,
lat 62°00'4 1 " N., to lat 62W43" N„ long 147 c 34'46" W., to long 147°34'54" W„
Talkectna Mts.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

1'ir.rm: 24. — Inrtrx map showing Albian

Tlie faunule characterized by Freboldicerax xingu-
lore Imlay contains Albian amnionites that are unlike
those in t lie Chitinn Valley or in California, but nre
identical with or closely similar to species in the west-
ern interior of Canada. The faunule is correlated
with beds in Canada that overlie the zone of Lem u ra-
ce rox belli and underlie the zone of OaxtropHtex kingi ,
but the evidence is not conclusive. If this correlation
is correct, it is probably younger than the lireweri -
cerox breweri faunule in the Chitina Valley on the
basis that that faunule contains a species of Lemuro-
cerox that occurs in the zone of Lcmvroccrax belli in
northern Alaska.

Other ammonite faunules of late Albian age are
possibly represented in the Chitina Valley at certain
localities near the hast* of Nizina Glacier and near the
mouth of Canyon Creek. The collections on hand,
however, contain only long-ranging species that could
be of Cenomanian age.

The Albian ammonites from the Chitina Valley be-
long to the same faunal province as the Albian am-
monites of California and Oregon as shown by the
presence of the genera llreieerirerox. Ilulcnitex. Puzo-
xiyello , and Lecouteitex. A possible connection with
the boreal province is indicated, however, by the pres-

localities In the Tnlkeotnn Mountains.

ence of Lemurorerox ( Svlxircthoplitex) and Callizoni-
cerox. In contrast tlie Albian ammonites from the
Talkeetna Mountains lielong to the same faunal
province as tlio.se in the western interior of Canada and
in northern Alaska. It appears, therefore, that the
Albian sen that covered the areas now occupied by
the Chitina Valley and Talkeetna Mountains had
broad connections with the seas in the western interior
of the continent and in California. Careful strati-
graphic collecting from the Albian beds in the Chitina
Valley would probably furnish the evidence, for pre-
cise interregional correlations.

SYSTEMATIC DESCRIPTIONS

Class CEPHALOPODA
Genus PHYLLOPACHYCERAS Spath, 1925

Phyllopachycerai chitlnanum Imlay, n. sp.

Plate 11. figures l-. r >

This species is represented only by the holotype.
Whorls ovate in section, a little higher than wide,
widest near middle of flanks, liecoming stouter during
growth. Flanks gently convex, rounding evenly into
umbilical wall and into arched venter. Umbilicus ex-
tremely narrow. Hotly chandler occupies three-fifths
of a whorl and appears to be nearly complete.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Fabi.e 3. — Genyraphir distribution of early Albion o mmonilet from the Chilina Valley ami Talkectna Mountains, Alaska

[N'umlHTi 1-21 refer to number; on figs. 23 nnd 21. Higher numbers are Geolog leal Survey Mesozoic locality numbers)

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i H-'J /otojitwm iro'av. n. sp. ,,

r^6(.vK*u* ImJay

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d. 1. 3m nil (WbilmVaJ)

Tlie ornamentation on the adapical part of the body
whorl consists of nearly microscopic raised lines.
These- are replaced adorally at n diameter of about .'11
nun by low rounded ribs on t he venter. Toward the
aperture the ribs become stronger and originate at
various heights on the middle and upper parts of the
flanks. All ribs are of equal strength on the venter
which they cross nearly transversely. The suture line
has the tetrnphyllie first and second lateral saddles that
are typical in the genus.

The holotype has a maximum diameter of 88 mm.
At a diameter of 35 mm, it has a whorl height of 22 mm
and a whorl thickness of ill nun. At the adapical end
of the body chamber, the whorl height is 18 mm, and
the whorl thickness is 10,5 mm.

This species compared with PhyUopnchyceras therc-
me (Anderson) (1938, p. 141, pi. 1*2, figs. 4, 5) from
California has a stouter whorl section, a smaller umbili-

cus. and finer, denser ribbing. It is particularly char-
acterized by its stout whorl section.

Type: Holotyi* USNM 1301 -HI.

Locality: VSQS Me*. Joe. 9402.

Genu* HYP0PHYU.0CERAS Salfeld, 1924
Hypophylloceras cf. H. californlcum (Anderson)
l'lnie 11. figure 2!)

One laterally crushed septate specimen bears ribbing
similar t<> that on If. wUfomieum (Anderson) (1938,
p. 143, pi. 12, fig. 7), hut the characteristics of that
species are not known sufficiently to permit identifica-
tion. II. onocnxc (Stanton) (1896, p. 76; Anderson,
1928, p. 112, pi. 11, figs. 1, 2) has much finer ribbing.

Figured specimen : USNM 130132.

Locality: USG.s Mb. loo. 9492.

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CRETACEOUS AMMONITES FROM CHITiNA VALLEY AND TALKEETNA MOUNTAINS

Oenus CALLIPHYLLOCERAS Spath, 1927
Calllphylloceraii nlzinanum Imlay, n. sp.
l’late II, figures (5-12

This s|>ecies is represented by 20 specimens, of which
most are small and septate. Whorls ovate in section,
higher than wide, highly involute. Flanks gently con-
vex, converging above to a rather narrowly rounded
venter. Umbilicus extremely narrow; wall steep.
Body chanilier represented by three- fourths of a whorl.

Surface of shell covered with very fine striae that
incline forward on the flanks in a gently flexous man-
ner and arch forward on the venter. Surface of mold
marked by sigmoidal constrictions that are barely evi-
dent at a diameter of 25 mm, but become fairly strong
adorally, and arch forward on the venter. Six con-
strictions are present on the body chamber. Fine lirae
are visible only on the venter. The suture line is
typical of the genus.

The small pnratype shown on plate 11, figures 10
and 11, at a diameter of 33 mm, has a whorl height
of li) mm, a whorl thickness of 15 mm. and an umbili-
cal width of 3 mm. On the holotype at a diameter
of -1(5 mm, the corresponding dimensions are 30, 21,
and 4 mm.

This species is distinguished from C. aldemoni
(Anderson) (1938, p. 143, pi. 11, figs. 3-0) by its con-
strictions and growth striae arching forward more
strongly on the venter, by lacking flexuous raised lines
on the flanks, and by having a higher whorl section.

Types: Holotype USN.M 130138. Parntyiie t'SNM 130139.

Locality: l"SGS Mes. toe. 9192.

Calliphylloceraa cf. C. alderioni (Anderson)

Plate 11. lilts. 13-17

Three specimens very closely resemble C. older, 'ion!
(Anderson) (1938, p. 143, pi. 11, figs. 3— ft ) from Cali-
fornia as far as their preservation and small size per-
mit comparison. Their Hanks converge rapidly toward
a narrowly rounded venter and are covered with fine
flexuous raised lines that arch forward gently on the
venter, and the internal molds bear five flexuous con-
strictions.

Figured specimen: t'SNM 1301(51.

Locality: USGS Mes. loc. 9972.

Oenus ANAGAUDRYCERAS Shimizu, 1934
Anagaudryceras aurarium (Anderson)

Plate 11. figures 18. 19. 24

Lytocrras i Kossmatctia ?) aurarium Anderson, 1938. (Jeol. Soc.

America Spec. Paper 1(1. p. 151, pi, 20. figs. 1. 2.

This species is represented in the ('hit inu Valley bv
28 specimens that agree very well with the original

description ami illustrations by Anderson except for
tin* presence of very fine, forwardly inclined regularly
spaced lirae. These are visible only on a few specimens
in places where some of the shell is preserved.

Type: Plc»inty|w t'SNM 130154.

Localities: USfJS Mes. Iocs. 2201. 8873. 9971. 14484. 14485.
Fragments |»>ssllily belonging to this s|>ecles occur at Mes. Iocs.
8880. 9489. 9950. 990(5.

Genus K0SSMATELLA Jacob, 1907
Kossmatella cappr Imlay. n. sp.

Plate 12. figures 17-22

Three specimens of this species are on hand. Whorls
in young stages depressed ovate and much wider than
high, in adult specimens liecoming siiliquadrate and
higher than wide, embracing preceding whorls about
two-fifths. Flunks on inner whorls strongly convex,
rounding evenly into nearly vertical umbilical wall
and into broadly rounded venter. Flanks on adult
body chamlier somewhat flattened, rounding fairly
rapidly into sleep umbilical wall and into moderately
arched venter. Umbilicus moderate in width, wall
steeply inclined to nearly vertical. Body chamber in-
complete, represented by slightly more than half a
whorl.

The entire surface of the shell is covered with fine
forwardly inclined lines. In addition both shell and
mold are marked by regular forwardly inclined con-
strictions that are most pronounced on the inner whorls
and near the aperture of tin adult body chandler. The
constrictions on the inner whorls demarcate prominent
lateral bulges that liecoine much less prominent
adorally on the penultimate whorl. The adult body
whorl has 15 constrictions.

The suture line has fairly symmetrical bifid saddles
and a bifid first lateral lobe.

At a diameter of 63 mm, the largest specimen from
Alaska has a whorl height of 29 mm, a whorl thickness
of 25 mm, and an umbilical width of 20 mm. At a
diameter of 58 nun the same measurements are 25, 22,
and 17 mm resjiectively.

The Alaskan specimens in general appearance are
similar to KoMmatclht a<jg**izianvm (Pictet.) ns fig-
ured by Jacob (1908, pi. 2, figs. 8-10) and differ mainly
by having much weaker bulges and by their constric-
tions inclining adapically near the umbilicus. They
show even greater resemblance to Ko**tnateHn' goine*i
(Anderson) (1038, p. 153, pi. 20, figs. 3-5) from Cali-
fornia, from which they differ by the presence of
lateral bulges on their inner whorls and by fewer con-
strictions.

100

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The species is named in honor of S. R. Capps in
recognition of many years of study of Alaskan geology.

Types: Holotype USNM 130100. Parataypes USN.M 1301-10.

Localities: USGS Mrs. Iocs. 0102, 14514.

Oenus TETRAG0NITES Kossmat, 1895
Tetragonites aff. T. timotheanus (Pictet)

Plate 12. figures 24-28

Some Alaskan specimens of this genus differ from
T. timotheanus (Pictet) (in Pictet and Roux, 1847,
p. 80, pi. 2, figs. 6a-b, pi. 3, figs, la-c) by having
parallel, instead of convergent flanks. They have been
described in detail by Matsumoto (1959, p. 77-79, pi.
22, figs, la-c, 2a-c) in a paper dealing mainly with
Cenomanian ammonites from the upper part of the
Chitina Valley. In that paper most of the occurrences
listed are from localities of late Albian to Cenomanian
age, but Mesozoic locality 0492, which is either of early
Albian or early middle Albian age, is also included.
The specimens figured herein are all from Mesozoic
locality 9492.

Fiyurcd specimen: USNM 130131.

Genus PTYCH0CERA8 d’Orbigrny, 1842
Ptychoceras c t. P. laeve (Gabb)

Plate 12, figure 23

Two small internal molds show parts of two closely
appressed limbs that belong mostly to the body cham-
ber. The smaller limb is much depressed. The larger
limb is nearly circular in section. The surface is nearly
smooth, being marked only by faint growth lines and
by several constrictions. The constrictions near the
adoral end of the larger limb are bordered by a
rounded rib that is most prominent on the venter.

These specimens differ from P. laeve (Gabb) (1869,
p. 144, pi. 25, figs. 21, 21a, b) in being much smaller,
but possibly belong to that species.

Figured specimen: USNM 130103.

Localities: USGS Mes. Iocs. 8872. 0972.

Genus VALDEDORSELLA BreUtroffer, 1947

Valdedoriella? whlteaveii Imlay, n. sp.

Plate 11. figures 20-23. 25-28

'/Ammonites (sp. lindet.). Whilenves, 1870. Geol. Survey
Canada Mesozoic Fossils, v. 1. p. 47. pi. 3. figs. 4. 4a.

Two small ammonites from the Chitina Valley
greatly resemble a small ammonite from the Queen
Charlotte Islands descrilied by Whit eaves (1876, p. 47,
pi. 3, figs. 4, 4a) and are possibly identical. They have
in common a broadly rounded, depressed whorl section,
a small deep umbilicus, a rounded umbilical margin,

and 6 or 7 sigmoidal constrictions that arch forward
on the venter. On the specimens from the Chitina
Valley, each constriction is posteriorly bordered by a
low rounded rib that is slightly swollen at the umbili-
cal margin. Also, a few weaker riblets occur on the
venter between the constrictions.

The suture line is rather simple. Its saddles are
slender and bifid; its first lateral lobe is trifid and
slightly shorter than the ventral lobe; and its auxili-
aries descend regularly to the umbilicus.

The holotype at a maximum diameter of 11.5 mm has
a whorl height of 6.5 mm, a whorl thickness of 8.5 mm,
and an umbilical width of 2 mm.

Except for a broader whorl section TV? whiteavesi
Imlay, n. sp. greatly resembles V. getulina (Coquand)
as illustrated by Pervinquiere (1907, p. 154, pi. 6, figs.
16a-c) from l>eds near the Aptian-Albian boundary in
Tunisia. TV houreqi (Collingnon) (1937, p. 18, pi. 2,
figs. 6, 6a, b, 7, 7a, b) from Madagascar is less de-
pressed and has stronger ribbing and wider saddles,
and its constrictions cross the venter nearly trans-
versely instead of arching forward. T r . akuschaensis
(Anthula) (1899, p. 104, pl. 8, figs. 3a-c) from the
Caucasus is more compressed and has wider saddles,
but is difficult to compare l>ecause of its larger size.

The specimens from the Chitina Valley show some
resemblances also to the upper Albian Puzosia chiri-
chemis Pervinquiere (1907, p. 152, pl. 6, figs. 17-20),
which species Breistroffer (1947, p. 60) assigns to
Lunatodorsella. a subgenus of Desmoeeras. That sub-
genus is distinguished, however, by a craterlike umbili-
cus, a ratber sharp umbilical edge, and straighter con-
strictions.

The range of Valdedorsella. according to Wright
(1956, L363), is Hauterivian to Aptian. Collignon
(1937, p. 19) notes that V. getulina (Coquand) exists
in both the Barremian and the Aptian of the Mediter-
ranean region, but predominates in the Aptian. lie
notes that T'. akuxchaemis (Anthula) occurs in Aptian
beds in the Caucasus and above the Aptian in the Clan-
sayes lieds in the province of Drome in southern
F ranee.

This occurrence in the Clansayes lieds is interesting
because it indicates that the genus Valdedorsella ranges
at least as high as the Aptian-Albian boundary.
Whether the Clansayes beds are placed at the top of
the Aptian (Breistroffer, 1947, p. 11-20) or at the base
of the Albian (Spath, 1941, p. 668; Collignon, 1949, p.
10!)), they are not much older than the beds in the
Chitina Valley, Alaska, that contain the lower Albian
ammonites herein descrilied.

Types: Hololyiw USNM 130145. Uaratype USNM 130140.

Locality: USGS Mrs. lor. 9192.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

101

Genas CALLIZONICERAS Spath, 1923
Subgenns W OLLEM AN NICER AS Breistroffer, 1947

Calllzoniceras (Wollemannicerat) alaskanum Imlay, n. sp.

Plate 12. figures 11-16

The sjiecies is represented by six specimens. The
holotype has i>een laterally crushed at the ndapical
end of the body whorl and slightly depressed at the
adoral end. Shell small, moderately compressed.
Whorls ovate, depressed, becoming less depressed
adorally, embracing about one-half of preceding
whorls. Flanks convex, rounding evenly into broadly
arched venter and into umbilical wall. Umbilicus
moderate in width; wall steeply inclined at base.
Body chamber on holotype is represented by three-
fifths of a whorl and appears to l>e nearly complete.

The ornamentation consists partly of gently flexous,
rounded ribs of moderate strength that tend to fade on
the venter. It includes some rather strongly flexuous,
pronounced constrictions that arch forward on the
venter and are bordered by flared ribs that are particu-
larly prominent on the venter. The primary ribs Itegin
low on the umbilical wall and incline forward to near
the middle of the flanks where about half of them bi-
furcate. A few primary ribs bifurcate considerably
lielow the middle of the flanks. All ribs, forked and
single, curve forward strongly on the upper parts of
the flanks, arch forward on the venter, and weaken
ventrally. On the paratypes the ribs do not quite fade
out. on the venter. On the holotvpe the venter of the
body chaml>er is nearly smooth except near the aper-
ture where the ribbing Itecomes a little stronger.
Tubercles are not present. Seven to eight constrictions
occur on each whorl. The suture line is too poorly
preserved to l>e traced.

The paratype (pi. 12, figs. 13, 14) at a diameter of
23 mm has a whorl height of 0 nun, a whorl thickness
of 11 nun, and an umbilical width of 6.5 mm. The
holotype has n more compressed whorl section but has
l>een somewhat deformed.

This species has the general appearance of Callizoni-
cents (Wollemanniceras) keilhacki Wollemann (1907,
p. 36, pi. 5, figs. 4, 4a, 5, 5a; Casey, 1957, pi. 7, figs.
4, 4a, 5). It differs by having a more depressed whorl
section, less flexuous constrictions and ribs, a greater
number of forked ribs, and ]>erhnps denser ribbing.

Types: Holotype I'SNM 1.30165. Parntypes t'SN.M 130166a, 1>.

localities: USGS Mos. loon. 8873, 007(1.

Calllzoniceras (Wollemanniceras) fohlinense Imlay, n. sp.

Plate 12. figures 1—10

The species is represented by five specimens. Shell
small, compressed. Whorls subquadrate, a little higher

than wide, embracing about one-half. Flanks gently
convex on inner whorls, liecoining flattened during
growth. Venter highly arched. Umbilicus moderate
in width, shallow; wall low, steeply inclined on inner
whorls, Incoming vertical on outer whorls; umbilical
edge evenly rounded on inner whorls, abruptly rounded
on outer whorl. Body chandler unknown.

The ornamentation consists of thick, gently flexuous
ribs and constrictions that incline forward on the
flanks, arch forward strongly on the venter, and be-
come progressively stronger and more flexuous during
growth. On the smaller whorls (pi. 12, fig. 6) the
ornamentation consists of variably spaced unbranched
ribs that liegin low on the umbilical wall, are strong on
the flanks, and nearly disappear on the venter. At a
diameter of about 13 mm some short ribs are inter-
calated high on the flanks. At greater diameters many
ribs branch near the middle of the flanks, others are
indistinctly connected with secondary ribs, and a few
remain unbranched. The ribs and constrictions on the
venter are much weaker than on the flanks at all stages
of growth, but liccome a little stronger during growth.
Generally the ribs laundering the constrictions on the
venter are a little stronger than the other ribs.

The suture line is simple. The auxiliaries do not
descend toward the umbilicus as in Callizoniceras
(Wollemanniceras) keilhacki Wollemann (1907, pi. 5,
fig. 5a), but rather trend radially as in C. hoyeri (Von
Koenen) (1902, pi. 38, fig. 6c).

The holotype at a diameter of 27 mm has a whorl
height of 10.7 mm, a whorl thickness of 9.5 mm, and
an umbilical width of 8 mm.

This species compared with C. alaskanum Imlay, n.
sp., has a subquadrate rather than a depressed ovate
whorl section and has stronger more flexuous ribs. It
Ijears much greater resemblance to the paratype of
C. keilhacki (Wollemann) (1907, pi. 5, figs. 4a, 4b),
but up|>ears to have more forked ribs and a less
rounded whorl section.

Types: Holoty|ie USN5I 1.30155. Pnratypes I'SNM 1.30156.

Locality: t'SGS Men. loc. 14484.

Genuj M0FFITITES Imlay. 1959

The original description of this genus is as follows:

Tills genus Is characterized t»y an inflated shell, moderate In-
volution, a whorl section that changes from ovate to coronate
during growth, by flexuous ribs and constrictions that arch
forward strongly on the venter, by frequent bifurcation of the
primary ribs into somewhat weaker secondary ribs near the
middle of the tlauks. by a tendency of the secondary ribs to
wenken and become striate as they near the middle of the
venter, by the occurrence of flared ribs adjacent to the con-
strictions. and by having a desmocerntld suture line whose
auxiliaries descend gradually toward the umbilical seam.

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102

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

It differs from the new genus KcnnicaUia with which it in
associated hv being much more Inflated, h.v having much
st rout'd- primary ribs, and by a tendency of its secondary ribs
to become striale on the venter. Its ornamentation bears some
resemblance to that of P*ciulahaplficcrua Hyatt (l'.MJO. p. 500),
but it is easily distinguished l>y having regularly furcating
ribs and a coronate wliorl section. It resembles Valtlciloraella
Brelstroffer (1947. p. tKt ) in shai>e and involution, but the dif-
ferentiation of its ribs Into primaries ami secondaries and the
considerable strength of its primary ribs |x- rmlt easy se(iaru-
tion of the genera. The same features distinguish it readily
from genera within the Ibdeodlscidae such as Axlicridiant*
Kiliait (1010. p. 265).

The type s|>eeies of M offline* is Moffltilc * rohuxtnx inday. n.
sp.

Tliis genus is named for Fred H. Mofflt in recognition of his
many important contributions to Alaskan geology as a member
of the U.S. Geological Survey.

Moffitites robuituj Imlay
Plate 13. figures 1-13

itoffllilc a robust na Imlay. 1059. Jour. Paleontology, v. 33, no. 1,
p. 181-182. pi. 20. tigs. 0-14.

The original description follows:

The species is represented by 30 sfiecimens. Shell stout,
moderate in size. Whorls ovate depressed, becoming stouter
during growth, embracing about throe- fifths. Flanks gently
convex on immature specimens, becoming highly convex on
adults. Venter highly arched in immature sjieciroens, be-
coming broadly rounded on adults. Umbilicus moderate in
width: wall inclined steeply, fairly high, rounding evenly into
flanks. Body chamber incomplete, but represented by nt least
half a whorl.

The ribbing Is gently tlexuous on the flanks, is arched for-
ward on the venter, and is variable in density. The primary
ribs are moderate in strength, are triangular in section, become
stronger centrally, and are generally narrower than the inter-
spaces. They begin low on the umbilical wall, incline forward
slightly on the wall and on the lower third of the llnnks. and
then recurve gently near the middle of the flanks where they
pass into, or are replaced by much weaker secondary ribs.

On immature specimens some of the primary ribs bifurcate
near t lie middle of the flanks. Others remain single on the
flanks, but may be separated from each other, or from forked
ribs by 1 or 2 secondary ribs that arise freely on the upi>er
parts of the flanks. On the penultimate and body whorls most
of the primary ribs bifurente near the middle of the flanks and
many of the pairs of secondary ribs are separated on the
venter by 1 or 2 intercalated ribs. In many specimens the sec-
ondary ribs fetal to weaken and lieenme striate along the mid-
ventral area. Inti this tendency varies considerably from one
s|ieeimen to another and from whorl to whorl. Tubercles are
not present at any growth stage.

All whorls are marked by 6 to 8 constrictions that are flcxtl-
oils on llie flanks and arch forward on the venters. The con-
strictions are inconspicuous on the immature whorls, but be-
come more pronounced adorally. Ou the outer whorls the con-
strictions are generally bounded by 1 or 2 swollen primary ribs
on the flanks and by a forwardly projected swelling on the
venter.

The suture line is dosiimoeratid in plan. Its auxiliaries de-
scend gradually toward the umbilical seam as in Deanwccra*.
Pacadohaploccra* or Vahlcdorxclla.

The holotype nt a diameter of 07 mm has a whorl height of
43 mm. a whorl thickness of 52 mill, and an umbilical width of
31 mm. At a diameter of till mm the other dimensions are 30.
41). and 20 nun res|ieotively. On paratyiie USNM 120875b nt a
diameter of 56 mm the other dimensions are 24. 37. and 18 mm
respect 1 vely.

Types: Holotyjie USNM 120874. I’aratypes USNM 120875a,
h. 120876a, l>.

Occurrence: U8G8 Mes. Iocs. 2147. 2101. 8873, 8875. 8876.
8878. 0480. 0076a. 0078. 14471. 14484. 14485. Fragments that
possibly belong to this species occur nt Mes. loe. 2173, 0071.
and 14467.

Hoffitltes crauus Imlay, a. sp.

Plate 14. figures 3-7

This species is represented by three specimens. It
differs from Mofjitite a robust us Imlay, n. sp., by having
a somewhat less depressed whorl section, much sparser,
coarser ribbing, and fewer intercalated ribs on the
upper part of the flanks, and the secondary ribs do not
become striate on the venter. The holotype has 26
primary ribs and only 2 secondary ribs for each pri-
mary. Specimens of .1/. robust us Imlay at a com-
parable size have from 33 to 35 primary ribs and a
little more than 2 secondary ribs for each primary.

The holotype nt a diameter of 35.5 mm has a whorl
height of 16.5 mm, a whorl thickness of 16.5 mm, and
an umbilical width of 8.5 mm. The suture, line is not
preserved.

Type*: Holotype USNM 130175. Paratyiie USNM 130176.

Localities: USGS Mes. loos. 8878. 14477, 14487.

Genus FREBOLDICERAS Imlay, 1959

The original description is as follows:

This genus resembles Callisoniccra * Spath (1023. p. 35) from
the upper Rnrreminn to lower Alhinii of Ettro|ie (Von Knenen.
1002. p. 58. pi. 0. flgs. 5a-o, p. 60. pi. 28. figs. 5a. b, Cn-c. 7 :
WoUeiimiin. 1007. p. 36. pi. 5. flgs. 4, 4a, 5, 5a : Brinkman, 1037.
p. 8-10. flgs. 4. 5). It differs by being more Involute; by its
whorl section being higher and more narrowly rounded: by its
primary ribs being more regularly-spaced, more swollen, and
confined generally to the lower part of the flanks: by Its con-
strictions being less rcgulnrly-s|Mced : and by having fewer sec-
ondary rilis. Its smooth body chamber and large sire may be
other distinctions. Its suture is very simple and closely re-
sembles that of Callisoniccra*. The type sjiecles of Frchohli-
ccra* is Frcbuldiccra* sinyalarc Imlay. it. sp.

Frcboldiceras tingulare Imlay
Plate 14. figures 8-17

Frchohli ccra* sinyalarc Imlay. 105!). Jour. Paleontology, v. 33.
no. 1. p. 182. 183. pi. 30. figs. 1-7.

The original description is as follows:

Four x|H>cimeus of this species have been found in the Tal-
kcetna Mountains at one locality. Shell compressed, discoidal.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

103

Whorls suborate In section, considerably higher than wide,
thickest near umbilicus, embracing about two-thirds. Flanks
gently convex in their lojver parts. but tailoring above to a
narrowly rounded venter. Umbilicus fairly narrow, wall
steeply inclined, rounding evenly Into flanks. Roily chamber
represented by at least three-fifths of a whorl.

The ornamentation of the septate jrnrts of the shell consist
mostly of prominent, flexuons. regularly-s|u»ccd primary ribs,
of deep. Irregularly-spaced constrictions, anil of flexuons striae.
The primary ribs begin high on the umbilical wall. Incline for-
ward and become swollen nenr the nmhllfcnl edge, and then
curve forward nenr the middle of the flanks where most of
them )>nss Into bundle’s of striae that arch forward gently on
the flanks and venter. The primary ribs that adjoin constric-
tions continue across the flanks and venter, but are more promi-
nent on the Internal mold than on the shell. Some specimens
at a few places have single, short secondary rlhs that are In-
tercalated between the primary ribs and continue across the
venter. Where shelly material Is preserved Its surface is cov-
ered with flue, flexuous striae that is coarser on the primary
ribs tlmu on the intersjiaoes. The periphery of the Internal
mold is strongly undulating. Wherever the shell is preserved
the periphery is nearly smooth.

The adult body chamber is nearly smooth. Faint flexuous
striae ure present in a few places where shell layers are pres-
ent. On the !>enultimnte whorl the primary ribs become much
weaker adorally and are barely visible near the last-formed
septa.

The suture-line Is very simple. It grontly resembles that of
the genus Callizonicera* (Wollemann, 1!HI7. pi. 5. fig. - r m ; V.
Koenen. 1002. pi. 0. tig. 5c. pi. 38. figs. fl. 7 ; Chapnt, 1020. pi. 1.
tigs. -la. b) in its broad first lateral saddle. In Its first lateral
lobe being slightly deeper than the ventral lobe. and In its
auxiliary saddles not being retracted ndapically nenr the um-
bilicus. In fact the auxiliaries ascend slightly ns they approach
the umbilical seam.

The holotype at a diameter of 55 mm. bus n whorl height of
2-1 mm, n whorl thickness of .10 mm nnd on umbilical width of
1-t mui.

This species resembles lA-murocera * irenense Mcl.cn rn (1!M5,
pi. 5. tig. 5. 1018. p. 21 from the Moosebnr formation of lirltish
Columbia, nnd probably belongs in the same genus. The pres-
ervation of the holotype of L. irenense is not sufficient, however,
to prove whether the resemblances are accidental or reflect
generic relationships.

Tillies: Holotype URN 1211868. USN.M 120860n-c.

Occurrence: USGS Mes. loo. 2-1877.

Genut KENNICOTTIA Imlay. 1959

The original description is as follows:

This genus is characterized by being fairly involute, by the
presence of iicrsistent primary ribs that bifurcate fairly regu-
larly near the middle of the flanks, by having flexuous ribs and
constrictions that arch forward strongly on the venter, by the
presence of some flared ribs adjoining the i-onstr let Ions, by re-
duction of the secondary ribs along the midline of the venter,
nnd by its suture line having regularly descending auxiliary
lolies. It shows resemblance to Pscuiloliaplorcrax Hyatt (1000,
p. 570) in amount of involution, whorl slm|s>. suture-line, pres-
ence of flexuous constrictions and ribs, and presence of bifur-
cating ribs. It differs, however, by having a more sulx|liadrnte
whorl section, a vertical umbilical wall. Hatter flanks, weaker

constrictions and (la rod ribs, nnd stronger, more regularly bi-
furcating primary ribs. It differs from V aldedorsella (Briest-
roffer. 1017. p. 60) In its whorl section being aubquadrate in-
stead of round and by the presence of bifurcating ribs. It
differs from Puzusia by (icing considerably more involute, by
the presence of bifurcating primary ribs, and by the auxiliary
lolies of Its suture line descending regularly instead of abruptly.
The type sjiecies of Kennicottia Is Kennicottia bifurc.aia Im-
lay, n. sp.

Kennicottia bifurcata Imlay
Plate 13, figures 1-6

Kennicottia bifurcata Imlay. 1039, Jour. Paleontology, v. 33.
n. 1. p. 183. 184. pi. 30. tigs. 8-13.

The original description is as follows:

This species is represented by 13 specimens. Whorls subo-
vate in immature siiecimens, becoming suhquadrate in adult,
embracing about three-fifths. Flunks gently convex, becoming
less so during growth, rounding Into highly arched venter.
Umbilicus fairly narrow ; wall low. vertical at linse. rounding
evenly into flanks. Body chamber unknown.

The ribbing Is gently flexuons on the flanks nnd arched for-
ward strongly on the venter. The primary ribs are somewhat
stronger than the secondary ribs. They begin low on the
umbilical wall, nre highest on the edge of the wall and become
rather broad ventrally. Most primary ribs bifurcate near the
middle of the flanks, but some remain single, nnd some are
indistinctly connected with secondary ribs. The se<-ondnry
ribs are reduced in strength along the midline of the venter.

From 6 to 7 weak flexuons constrictions occur per whorl.
They become more conspicuous adorally nnd are most con-
spicuous on the venter. On the adoral part of the holotype.
they nre bounded by swollen ribs.

The suture line is desmocerated in tyite. Its regularly de-
scending auxiliary lobes contrast with the retracted auxiliaries
In Puzosla. but are comparable with those In Psrudobaploeerax.

The holotyis* at a diameter of 63 mm has a whorl height of
29 mm. a whorl thickness of 25 mm. and an umhilicul width
of 15 mm.

This species has a general resemblance to Puzosla sub-
i/uadrata Anderson (1938. p. 186. pi. 45. figs. 3-5) from Cali-
fornia. but differs by having much stronger primary ribs thnt
bifurcate fairly regularly, by Its ribbing being less flexuous. by
its umbilical wall rounding more evenly into the flanks, nnd
by its auxiliary lobes descending much more gradually toward
; the umbilical seam (compare Anderson. 1938, p. 183. text. ftg. 3.
no. 6).

Tillies: Holotype USN.M 129870. Pnrntype USN.M 129871.

Occurrence: USGS Mes. Iocs. 8873. 9972. 14471. 14484.

Kennicottia rugosa Imlay, n. ip.

Plate 15, figures 7-13

The species is represented by three specimens. Shell
fairly large for genus. moderately compressed. Whorls
subquadrate in section, lieoomilig stouter during
growth, embracing about three-fifths of preceding
whorls. Flanks gently convex, becoming less so dur-
ing growth, rounding evenly into broadly arched
venter. Umbilicus fairly narrow; wall moderate in
height, vertical at base, inclined above, and rounding

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

rather abruptly into flanks. Body chamber incomplete,
but represented by at least half a whorl.

The ribbing is flexnous on the flanks, arched for-
ward on the venter, and somewhat reduced in strength
along the midventral lines. The primary ribs l>egin at
the umbilical seam, and incline forward gently on the
lower part of the flanks, and generally divide near the
middle of the flanks into pail’s of weaker secondary
ribs that arch forward considerably. Some secon-
dary ribs are indistinctly connected with the primary
ribs, and some arise freely above the middle of the
flanks.

About 8 to 0 flexnous constrictions occur on each
whorl. These constrictions are inconspicuous on the
smaller whorls, but become more prominent during
growth. Some constrictions on the penultimate and
body whorls are bounded by swollen rilis that on the
venter may become flared.

The suture line is poorly preserved and cannot lie
traced.

The holotype at its adoral end has a whorl height of
'■8 mm and a whorl thickness of 51 mm. The paratype
shown on plate 15, figures 7, 8, 11, at a diameter of
4-2 mm, has a whorl height of 20.5 mm, a whorl thick-
ness of 18 mm, and an umbilical width of 10 mm.

This species is distinguished from any species of
Puzosia by being more involute and by having jier-
sistent primary ribs of which most divide near the
middle of the flanks. It differs from A', bifurcata Im-
lav, u. sp., by having a stouter whorl section, coarser,
sparser ribbing, and a more abruptly rounded umbili-
cal edge.

Type*: Holotype l.'SNM 130152. I’nratypes fSN’.M 130153a, li.

Localities: USGS Mes. toes. IHS0, 14-185.

Genus PUZOSIA Bayle, 1878
Puzosia alatkana Imlay, n. ip.

Plate 16. flenres 1-13

The species is represented by about !)<) specimens.
Whorls elliptical in section, higher than wide, widest,
near the umbilicus, embracing alrnut one-half of pre-
ceding whorls. Flanks flattened, converging slightly
toward the highly arched venter. Umbilicus moderate
in width; wall steeply inclined in early growth stages,
becoming vertical in adult, rounding evenly into flanks
in early stages, but abruptly in adult. Body chamber
represented by three-fifths of a whorl.

The ornamentation on immature specimens consists
of strongly flexuous striae, rihlets, and constrictions
that arch forward considerably on the venter. They
curve forward on the umbilical wall and base of the
flanks, curve backward slightly ladow the middle of 1

the flanks, and then curve forward strongly on the
upper part of the flanks. The riblets are most pro-
nounced on the venter and upper parts of the flanks,
but many of the constrictions are bounded on one, or
on both, sides by riblets that liegin at the umbilical
margin. The constrictions number from 6 to 7 per
whorl and are much more conspicuous on the internal
molds than on the shell.

During growth the constrictions become more deeply
impressed and more strongly arched on the venter.
The ribbing weakens on the lower part of the flanks,
but. liecomes stronger on the venter and on the upjier
part of the flanks. On the adult body chamber there
are from 18 to 12 ril>s lietween successive constrictions.
Generally the ribs bordering the constrictions on the
venter are somewhat swollen.

The suture line descends fairly rapidly toward the
umbilicus. It is characterized by the second lateral
saddle being a little higher than the first lateral
saddle. This feature occurs in the genus Melchiorites
as figured by Fallot (1920, p. 255-257) as well as in
Puzosia (see Spath, 1923, pi. 2, fig. 3e).

The holotype at a diameter of 41 mm has a whorl
height of 17 mm, a whorl thickness of 13 mm, and an
umbilical width of 13.5 mm. The same dimensions of
the small paratype shown on plate 1(5, figure 11, are
29, 12, 10, and 8.5 mm, respectively.

This species shows resemblances with the genera
3/ elchiorites, Puzosia , and Hulenite*. In lateral view
it resembles Puzosia quenstedti I’arona and Bonnrelli
(1897, p. 81, pi. 11, figs. 3a, b) from the Albian of
Europe, but its ribs and constrictions arch forward
much more on the venter, and it develops an abrupt
instead of an evenly rounded umbilical edge. The pat-
tern of its ornamentation and the slu\j)e of its umbili-
cal edge is so similar to that of Iluhnites reesidei
(Anderson, 1938, p. 187, pi. 38, figs. 2, 3) from the late
Aptian to early Albian of California as to suggest that
the two s|K‘cies are closely related. It may l>e dis-
tinguished from //. ree*idei, however, by lieing more
compressed, by having more projected ornamentation
on the venter, by its ribs showing no tendency to fade
on the venter, and by the ribs on the immature whorls
Iteing much finer and more flexuous. It also shows
considerable resemblance to ribited species of Meichior-
ites — such as M. indigenes Anderson (1938, p. 184, pi.
(57, fig. 3, pi. 68, fig. 2) from the Aptian of Cali-
fornia, but it is distinguished by developing an abrupt
umbilical edge and finer, denser, more sigmoidal rib-
bing.

Types: Holotype t'SNM 130143. I “a ra types USNM 130144.

1 Locality: uses Mes. lee. 11102.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

105

Genu* BEUDANTICERAS Hitzel, 1905
Beudanticeras glabrum (Whitcaves)

Plate 10. figures 14-21

1‘taccnliccra* glabram Whiteaves, 1889. Contr. to Cnmitlinn
Paleontology, v. 1. pt. 2, p. 172. pi. 24, figs. 1. la, b.
Dctmoccra* affine vnr. glabram Whiteaves. 1803, Royal Soe.

Canada. 1st ser.. v. 10. p. 115. pi. 9.

Bcudanticera* glabram (Whiteaves). McLearn. 1031. Royal
Soc. Canada. Trans., ser. 3. v. 25. see. 4. p. 3.
‘‘Beadanlicera* ef. R. glabram Whiteaves. MeLearn. 1045.
Geol. Survey Cannda I’aiier 44-17 (2d ed.), pi. 4. figs.
2. 3.

Bcudanticera* glabram (Whiteaves). Warren. 1017. Jour.
Paleontology, v. 21. p. 121, pi. 30. figs. 1-1.

Nine specimens of Beudanticerax . obtained in the Till*
keetnn Mountains, very closely resemble the original
type specimen described by Whiteaves in their nar-
rowly rounded whorl section, very narrow umbilicus,
broad asymmetrical first lateral loin*, low, broad sad-
dles, and numerous auxiliary lol>os. Furthermore, five
of the specimens are nearly as smooth as the type, l>eing
marked only by fine flexuous striae that are barely visi-
ble under oblique lighting. The other four differ from
the type, however, by having riblets and weak bulges
on the flanks. In addition several of the specimens
bear one or more weak constrictions per whorl.

The presence of striae and riblets on some of the
specimens front the Talkeetna Mountains agrees with
the observations of Warren (1947, p. 121) based on
specimens of Beudantieerax ghthrum (Whiteaves) from
the Lower Mackenzie River valley in Canada. In his
specimens, however, the ornamentation is most con-
spicuous near the umbilical border and constrictions
are absent.

These differences are probably not of specific value
considering that the number and strength of constric-
tions is a variable characteristic in many species of
Beudantirerax. that the determination of the presence
of weak constrictions may l>e difficult on poorly, pre-
served specimens, and that the distribution of riblets
on the flanks may reflect individual variations. The
fact that most of the specimens from the Talkeetna
Mountains agree very well in their characteristics with
the liolotype of B. ghthrum (Whiteaves) is herein
given more weight, than the minor differences in orna-
mentation mentioned above.

This species is characterized by its umbilicus being
narrower and its saddles broader and lower than in
most species that have Iteen assigned to the genus
Beudantirerax. The narrowness of the umbilicus is
comparable, however, with that of />. xutherlandi
(Etheridge) (Whitehouse, 1928, p. 202, pi. 25, fig. 4)
from Australia, which species di tiers from B. glabrum
by its stouter whorls. F urthermore the sutural pattern

is similar to that in B. htevigatum (J. de C. Sowerby)
(Spath, 1923, p. 5G) from England; this species differs
by its wider umbilicus and stouter whorls. Because of
these similarities B. ghthrum is herein considered ns
ladonging within the range of variation of Beudanti-
cerux. although possessing peculiar characteristics
somewhat different from typical s|>ecies of Bevdanti-
cerax in Europe. The differences are no greater than
among certain Jurassic ammonites from western North
America that Arkell (in Arkell and Playford, 1954,
p. 596-597) assigns to genera based on European
species even though they possess certain features that
are not characteristic of the types.

Type: Plpsioty|>es VSNM 130149.

Locality: US(!S Men. loc. 24877.

Subgenu* ORANTZICERAS Imlay, I960
Bcudanticera* (Orantziceras) multicomtrictum Imlay
Plate 14. figure* 1. 2

Rcatlanllrcrax ( Orantstcera s) multiconxtrictum Imlay. I960.
U.8. Geol. Survey Prof. Paper 335 (la prexx).

This species is characterized by many regularly
spaced falciform constrictions, by broadly bundled
striae on its flanks, and by a scaphitoid l>ody chaml>er.
Its largest specimens are considerably larger than any
descril>ed European species of Beudantieerax , but are
only aliout half as large as B. affine (Whiteaves) from
Canada and northern Alaska. It resembles B. affine
more closely than any other descrilted sjtecies of Beu-
dantirerax. but differs by having nearly twice as many
constrictions |>er whorl, a somewhat wider umbilicus,
a shorter second lateral lol>e, and a more compressed
whorl section.

Type*: liolotype USNM 128721. Paratypes l.’SNM 128722,
128723.

Localities: USGS Me*. Iocs. 24877. 25320. 25329.

Genus BREWERICERAS Catey. 1954
Brewericeras breweri (Gabb)

Plate 17. figures 3-10, 12. 13

Ammonite* breircri Gabb. 1864. Paleontology Calif, v. 1. p. 62.
pi. 10. fig. 7.

Gabb. 1869. Gabb. Paleontology Calif., v. 2. p. 130. pi. 19.
tig. 5b. pi. 20. fig. 5.

Gabb. Whiteaves. 1876, Geol. Survey Canada Mesozoic
Fossils, v. 1. p. 21. pi. 1. figs. 2. 2a. 3. 3a.
lieudantirera* brcireri (Gabb). Anderson. 1938. Geol. Soe.
America S|»ee. I’aiier 16. p. 189. pi. 43. fig. 3, pi. 44,
figs. 1. 2.

Itreirerierra* breircri (Gabb). Casey. 1954. Washington Acad.
Sol. Jour., v. 44. no. 4. p. 112.

The 13 Alaskan sjjecimens of this sjieeies on hand
are all compressed, have flattened flanks, a highly
arched venter, a vertical or nearly vertical umbilical

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106

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

wall, and a fairly sharp umbilical rim. They all de-
velop sigmoidal ribs that bear extremely weak, for-
wardly inclined swellings at the umbilical edge, that
are prominent and sparse on the upper part of the
flanks, and are reduced in strength on the venter and
on the lower parts of the flanks. They show consider-
able variation, however, in strength of ribbing and in
the stage of growth at which ribs first appear. In some
specimens sigmoidal ribs appear at a diameter as small
ns 20 mm. In other specimens ribs first, appear at a
diameter of 50 mm. The costate parts of internal
molds bear constrictions that are conspicuous only
on the venter. The suture line is similar to that of
the genus Beudanticeraz.

Type: Pleslotype USNM 130133.

Locality: USGS Mes. loc. 9492.

Brewericeras cf. B. hulenense (Anderson)

Plate 17. figures 11, 14-10

linttlaiitlccra * hulencnsc Anderson, 1038, Gent. Snc. America
Spec. Paper 10. p. 100. pi. 44, figs. 3. 4.

Iticiccriccrax hulencnsc (Anderson). Casey. 1954. Washington
Acad. Set. Jour., v. 44, no. 4. p. 112.

Associated with li. breweri (Gabb) at Mesozoic lo-
cality 041*2 are some ammonites that are possibly only
a smooth variant of that species. They differ, how-
ever, by having a smaller umbilicus, slightly flatter
flanks, and much weaker, finer ribbing that develops at
a later growth stage. In addition the larger specimens
have a slightly raised umbilical rim. These specimens
have hitherto been assigned to “ Ammonites " haydeni
Gabb (Martin, 102(5, p. 34(5 ; Moflit 1038, table opposite
p. 80; Imlav and Reeside, 1054, p. 220), but their
whorl sections compare in stoutness with those of li.
hvlenense (Anderson) (1038, pi. 44, fig. 4) rather than
with those of li. hay deni (Gabb) (18(54, p. G2, pi. 10,
fig. 8n), which has similar weak ornamentation.

Tin II nil specimens: USNM 130130. 130150.

Localities: USGS Mes. loc. 0402. 14514.

Genus DESM0CERAS Zlttel, 1864
Sesmoceras? sp. juv.

Plate 17. figures 1—1

The species is represented by one internal mold.
The specimen is small and has a subquadrate whorl
section. At a diameter of 2(5 mm, its whorl height, is
13 mm, its whorl thickness is 14 mm and its umbilical
width is 4 mm. The adoral part of the internal mold
is marked by two conspicuous gently flexuous constric-
tions that arch forward slightly on the venter. Be-
tween the constrictions on the venter are faint riblets.
The suture line is typical of Dexmocerns.

This species differs from D. voyi Anderson (1938,
p. 180, pi. 40, figs. 4-8) by having a subquadrate in-
stead of an ovate whorl section. It is so much smaller
than the figured sjjecimens of D. merriami (Anderson)
(1902, p. 103, pi. 6, figs. 135-138; 1938, p. 181, pi. 43,
figs. 1, 2) that comparisons with that species would
l>e meaningless.

Figured specimen: USNM 130135.

Locality: USGS Mes. loc. 0192.

Genus PARASILESITES Imlay, 1999

The original description (Imlay, 1959, p. 184) is as
follows:

Tills genus is characterized by Its fairly evolute shell, wide,
shnllow umbilicus, strongly flexuous ribs and constrictions,
presence of umbilh-nl bullae, occasional rib furcation on the
flanks, and by the auxiliaries of Its suture line descending only
slightly. It differs from the Barremian genus Sllcsitcs by the
presence of umbilical bullae, by the furcation of some ribs low
on the flanks, by the ribs being Inclined forward strongly at
the edge of the umbilicus, and perhaps by Its auxiliaries not
curving ndornlly. It differs from the npis>r Aptlnn-lower Alblan
genus Seosllesites by the presence of umbilical bullae, by Its
ornamentation being much more sigmoidul. by its ribs branch-
ing much lower on the flanks, and by its primary ribs not
splitting Into many tine secondary ribs on the upper parts of
the flanks. The suture line of Parasllesttes Is similar to that
on small specimens of Silcsilcs and Samites ilex (Fallot 1920a.
p. 54, 55; 1920b, p. 20!t-213). The tendency in the Silestidae
(Wright. 1957. p. 12572) for the auxiliaries to curve forward in
advance of the first saddle, ns illustrated by Uhlig (1883.
pi. 18, figs. 11-14), does not bar Paratilesites from that
family considering that the tendency, as discussed by Fallot
(1920b, p. 209) Is general only among adults. The tyi*e
species of Parasilesites is Parasilesites bulla tus Imlay. n. sp.

Paraailesltei bullatns Imlay
Plate 18. figure 1-8

Parasilesites bullatus Imlay, 1959. Jour. Paleontology, v. 33.
no. 1, p. 184. pi. 29. figs. 1-8.

Only two specimens of this H|>eolea are known. Whorls
ovate in section, a little higher than wide, embracing about
two-flftlis. Flanks gently convex, rounding evenly into highly
arched venter. Umbilicus fairly wide, shallow; umbilical wall
low, steeply inclined, rounding evenly into flanks. Ilody
chnmlier Incomplete, represented by at least half a whorl.

The innermost whorls, exposed in the umbilicus of the tyjie
s|K*cimens. are marked by 7 or 8 deep, forwardly Inclined con-
strictions nml by faint forwardly Inclined riblets. On the
|>cnu)timnte whorl the riblets are a little stronger and more
flexuous. and number from 5 to 7 between successive con-
strictions. Those riblets adjoining constrictions are a little
larger than the others and some of them bear weak bullae near
the umbilical margin. On the body whorl both constrictions
and ribs become stronger, many ribs are Initiate, and some rib
branching occurs at the bullae. On both the penultimate and
Isidy whorls the ribs and constrictions arch forward on the
venter and most of the ribs are somewhat weakened on the
venter. The venter of the Internal mold at the Iwginnlng of the

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

107

body chamber bears n distinct groove that has a length of only

8 mm. The ribs end abruptly at this groove and some terminate
in swellings. The groove may represent a deformity and
probably is not of specific Importance.

The suture line is very simple. Its auxiliaries descend only
slightly toward the umbilical seam. The ventral lobe Is
nearly as long ns the first lateral lobe.

The holotype at a diameter of 27 nun has a whorl height of

9 mm, a whorl thickness of 8 mm. and an umbilical width of
11.5 mm.

The species is characterized by developing distinct umbilical
bullae, by having fairly regularly-spaced constrictions and
ribs, and by some of the ribs bifurcating from the bullae. The
small pnmt.v|K» resembles Ritealtes puzoxtaformia Anderson
(1038. p. 191, pi. 20, figs. 0. 10) from the early Albiun of Cali-
fornia. but is stouter, has coarser ribbing, more and deeper
constrictions, and bears weak umbilical bullae.

Types: llolotypc U8X.M 129872. Paratype USNM 129873.

Occurrence: USGS Mes. loe. 9492.

Farasilesitei irregularis Imlay, n. sp.

Plate 18. figures 0-17

This species is represented by three specimens. Shell
compressed, discoidal. Whorls subquadrate in section,
higher than wide, embracing about one-third. Flanks
flattened, rounding evenly into moderately arched
venter. Umbilicus fairly wide, shallow; wall low,
steeply inclined, rounding evenly into flanks. Body
chamber represented by at least half a whorl. Aper-
ture sinuous and has a pronounced ventral projection.

The ornamentation of the septate whorls, exposed
in the umbilicus of the holotype, consists of 0 deep,
flexuous constrictions between which lie from 2 to 5
prominent, irregularly spaced, single flexuous ribs.
The rilis adjoining the constrictions are somewhat
stronger than the other rilis and many of them are
swollen on the umbilical edge. Both constrictions and
ribs weaken considerably on the venter and arch for-
ward gently on the venter.

On the flanks of the body chamber the constrictions
and rilis become more flexuous, stronger, and more ir-
regularly spaced. Many of the ribs are distinctly
bullate at the umbilical edge. On the venter both con-
strictions and ribs arch forward strongly, the constric-
tions are narrow and deep, and the ribs are highly
variable in strength. Most of the ribs bordering the
constrictions on the venter are swollen. Between these
ribs are bundles of riblets or striae that arise from the
flank ribs on the margin of the venter and tend to fade
out on the venter or to pass into swollen ribs.

The suture line is very simple, and its auxiliaries
descend only slightly toward the umbilicus.

The holotype at an estimated diameter of 24 nun has
a whorl height of 8 mm, a whorl thickness of 7 mm,
and an umbilical width of 10 mm.

J346JI O-flO — 4

The presence of umbilical bullae readily distinguish
this s|iecies from all species of Si/e.xitex. but its irregu-
lar ribbing liears some resemblance to that of S. vulpes
(Coquand) as figured by Uhlig (1883, p. Ill, pi. 18,
figs. 8, 0) from the Barremian of the Carpathian
Mountains.

Types: Holotype USNM 130147. I’aratypes USNM 130148.

Locality: USGS Mes. loe. 9192.

Genus HITLERITES MaUumoto, 1995
Hulenltes cf. H. reesldei (Anderson)

Plate 18, figures 18-21

The genus HulenUex (Matsumoto, 1955, p. 122) is
represented in the Chitina Valley by 4 specimens, of
which 1 is much smaller than the other 3. Shell com-
pressed, discoidal. Whorls ovate in section, higher
than wide, liecoming higher during growth, embracing
about one-half preceding whorls. Flanks gently con-
vex, liecoming flatter during growth, rounding evenly
into highly arched venter. Umbilicus moderately
wide, shallow; umbilical wall low, vertical at base,
rounding rather abruptly into flanks. Body chamber
incomplete, represented by at least half a whorl.

The inner whorls, exposed in the umbilicus, bear
many deep, forwardly inclined constrictions, but other-
wise are smooth. The outer whorl of the smaller
figured specimen has nine flexuous constrictions that
arch forward strongly on the venter and become more
deeply impressed during growth. Weak, forwardly
inclined riblets are barely visible on the upper part
of the flanks and on the venter. The outer whorl of
the larger specimens liears constrictions that are deep
near the umbilicus and shallow on the venter. Between
successive constrictions are from 7 to 12 fine, forwardly
inclined ribs that liegin lielow the middle of the flanks,
arch forward on the venter, and weaken along the mid-
ventral line. Some of the ribs bordering the constric-
tions are swollen.

The suture line cannot lie traced accurately.

The larger specimen illustrated at a diameter of 33
mm has a whorl height of 13.5 mm, a whorl thickness
of 11 mm, and an umbilical width of 12 mm.

The largest specimens from the Chitina Valley are
comparable in size with the small paratype of Ilulenites
reexidei (Anderson) (1938, p. 187, pi. 38, fig. 3) from
California. They appear to have finer ribbing, a
stouter whorl section, and a wider umbilicus. As these
differences are all minor and as the range of variation
in II. reexidei (Anderson) is unknown, the establish-
ment of the Alaskan specimens of Ilvlenitex as a dis-
tinct species does not seem justified at present.

Figured specimen: USNM 130134.

Localities: USGS Mes. loe. 9180. 9492, 14400.

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108

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Genas CLEONICERAS Parona and Bonarelll, 1886
Cleoniceras overbecki Imlay, n. sp.

Plate 111, figures 36-39

One small specimen of Cleoniceras has been found in
the Chitina Valley. Whorl compressed, much higher
than wide, widest at umbilical edge, embracing about
three-fourths of preceding whorls. Flanks flat, con-
verging from umbilical edge to narrowly rounded
venter. Umbilicus narrow; wall low, vertical at base,
steeply inclined above, rounding abruptly into flanks.
Body chamber unknown.

The umbilical edge bears 15 weak bullae that lx*come
weaker adorally. From these bullae pass weak, slightly
flexuous ribs that incline forward on the flanks and
arch forward on the venter. Some ribs remain single,
but many bifurcate on the lower third of the flanks.
Other ribs arise freely between the lower third and
the middle of the flanks. All ribs become stronger
ventrally, but are reduced somewhat in strength along
the midventral line. There are 42 ribs on the upper
part of the flanks, or nearly 3 secondary ribs for each
primary.

The suture line cannot be traced. The figured speci-
men at a diameter of 38 mm has a whorl height of 18
mm, a whorl thickness of 10 mm, and an umbilical
width of 7.5 mm.

The Alaskan species somewhat resembles the smnll
specimen of Cleoniceras clean (d'Orbigny) (1841,
pi. 84, fig. 3) from France. That species, however,
judging from a plaster replica of a typical specimen
furnished by Raymond Casey of the British Geologi-
cal Survey, has more prominent bullae and much
stronger, more flexuous ribs. C. bicurvatoides (Sin-
zow) (190!), p. 29, pi. 2, figs. 7-18) from southern
Russia has much more flexuous ribs and less prominent
umbilical bullae. C. baylei (Jacob) at a comparable
size, as figured by Spath (1925, p. 93; 1923, pi. 4, figs.
6a, b), has a much stouter whorl section. C. leigh-
toncnse Spath (1942, p. 701, 702, text fig. 247) is simi-
lar in shape and ornamentation, hut is not strictly
comparable because of the much greater size of the
type. The adorn] weakening of the ribs and bullae on
the Alaskan species indicates that it loses its ornamen-
tation at a much smaller size than does C. Icightonense
Spath.

The Alaskan s|x*eimen is the only one yet described
from the Pacific coast of North America that fits the
definition of Cleoniceras in all particulars. As its
characteristics do not match those of the described
species of Cleoniceras from Eurasia, it is deemed
worthy of specific rank even though its adult charac-
teristics are unknown.

This species is named in honor of R. M. Overbeck,
who collected many of the ammonites from the Chitina
Valley described herein.

Type: Holoty|»e t'SNM 130H1.

Locality: USGS Men. loc. 9492.

Genus PUZ0SIGELLA Casey. 1954
Puzosigella cf. P rogersi (Hall and Ambrose)

Plate 1!), figures 38-35

Three specimens from the Chitina Valley probably
belong to “ Sonnratia ” rogersi Hall and Ambrose ( 1916,
p. 69) as interpreted by Anderson (1938, p. 197, pi. 20,
figs. 6, 7). They are closely similar to the small plesio-
tyj>e figured by Anderson on his plate 20, figure 6, but
differ from the larger specimen figured by Anderson by
losing their umbilical bullae at an earlier growth stage
and by having finer, more closely spaced secondary
ribs. Such differences appear to be normal for the
species judging from the specimens in the Geological
Survey collections from Oregon and California. As
these collections show that the genus Puzosigella is
characterized by considerable variability, the validity
of the s|>ecies discussed by Anderson should be estab-
lished thoroughly lx*fore additional species are de-
scribed. The Alaskan specimens may represent a dis-
tinct s|x*cies from any described, but such cannot be
proved now. The presence of the genus Puzosigella in
Alaska is itself of stratigraphic importance as Puzo-
sigella in California and Oregon is restricted to beds
of early Albian age.

Figured specimen: USNM 130168.

Locality: USGS Mes. lot;. 8877.

Genus LECOKTEITES Casey, 1954

This genus includes shells that are compressed and
moderately involute and that develop a vertical umbili-
cal wall. The shell is marked by flexuous ribs that are
arched forward considerably on the venter and are
reduced in strength along the midventral line. Bi-
furcation near the middle of the flanks is common.
Weak flexuous constrictions that may lie bordered by
flared ribs on the venter are more evident on the in-
ternal mold than on the shell. The most finely ribbed
species develop a sharp umbilical rim and weak umbili-
cal bullae. The more coarsely ribbed species develop
an abruptly rounded umbilical rim and more or less
swollen primary ribs. The genus Puzosigella Casey
(1954, p. 110) differs from Lcconteites mainly by hav-
ing more prominent umbilical bullae, by the flanks
ribs originating in bundles at these bullae, and by ]>os-
sessing many, rather conspicuous, narrow constrictions
on immature specimens.

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CRETACEOUS AMMOXITE8 FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

109

Leconteitei modeitus (Anderson)

Plate 10, figures 4-0

Cleoniecras mndcstum Anderson, 1938. (leol. Soe. America S|>ee.
Paper 16. p. 19$. pi. 50, tigs. 2-4.

This species is represented in the Chitinn Valley by
three specimens that compare closely in shape and rib-
bing with the paratypes from California figured by
Anderson on his plate 50, figures 3 and 4. They all
differ from the type specimens of L. lecontei (Ander-
son) (1938, p. 192, pi. 38, fig. 4, pi. 47, figs. 3-5) by
having weaker less flexuous ribs and less conspicuous
umbilical tubercles. However, collections on hand from
California and Oregon suggest that L. modextus is
merely a smooth variant of L. lecontei. This matter
cannot be settled until larger collections are available.
Illustrations of L. lecontei ( Anderson) are shown on
plate 19, figures 1-3, for comparison with the Alaskan
specimens of L. mode stun (Anderson) and L. dearm
(Whitenves) deserilied herein.

Type: Plesiotypes USNM 130172. 130173.

Localities: USGS Men. lop. 9971. 11381).

leconteites deansi (Whiteavei)

Plate 10. figures 7-14

Oleostephanus ( Astleria ) deans! Whitenves. IK! 13, Canadian
Record Science p. 442—444, pi. 7, tigs. 1. la.

The species is represented by 35 specimens. Shell
small, discoidal, compressed. Whorls subovate, higher
than wide, embracing about three-fifths. Flanks flat-
tened below, converging slightly above to narrowly
round venter. Umbilicus fairly narrow; wall low,
vertical, rounding rather abruptly into flanks on inner
whorls, but developing a rim on adult body chamber.
The body chandler represents about three- fifths of a
whorl.

The ribbing is fine and strongly flexuous. The pri-
mary ribs incline forward on the umbilical wall and
on tlie lower third of the flanks where they recurve and
then pass into pairs of slightly weaker secondary ribs
that incline forward strongly on the venter. Bifurca-
tion on the inner whorls occurs on the lower third of
the flanks, but during growth the points of furcation
rise to the middle of the flanks. In a few places furca-
tion occurs at or near the umbilical edge. Many pairs
of secondary ribs are separated by single ribs that arise
aliove the middle of the flanks. All ribbing is much
reduced in strength on the venter, even where shelly
mnterial is preserved. Tuliercles are not present, al-
though some of the primary ribs on the body whorl
are faintly swollen at the umbilical edge. Each whorl
is marked by five or six weak constrictions that are
most evident on the venter.

The suture line is imperfectly preserved. It is char-
acterized by the first lateral lobe being much longer
than the ventral lobe. Its general plan is similar to
that of L. lecontei (Anderson) ( 1938, p. 183, text fig. 3,
no. 5, pi. 47, fig. 3), but its major lobes and saddles
are more slender and less frilled, and its auxiliary
lobes are much smaller.

The specimen shown on plate 19, figures 9-11, has
been only slightly compressed. At a diameter of 40
mm, its whorl height is 18.5 mm, its whorl thickness is
13.5 mm, and its umbilical width is 10 mm. These di-
mensions are similar to those of the holotype.

L. dearm. (Whiteaves) in general apjienrance is simi-
lar to Leconteites lecontei (Anderson) (see pi. 19, figs.
1-3) from the early Albian of California and Oregon,
but may lie distinguished by having stronger primary
ribs, by lacking tubercles, and by developing a sharp
umbilical rim at a much later growth stage.

Type: Plesiotypes L’SNM 130104. 130170.

Localities: USU8 Men. Iocs. 2201. 8872, 0967a. 9972. Frag-
mentary »|KH-imens |xmdbly belonging to L. deansi (Whitenves)
were found at Men. Iocs. KH73. KK80, 9067, 9973. 14484.

Leconteites cf. L. deansi (Whiteaves)

Plate 19. figures 15-27

From the same lieds as specimens assigned to L.
dearm (Whiteaves) and in part from the same, locali-
ties (Mes. lot'. 8872, 9972) have lieen obtained 25 speci-
mens of Leconteites that differ from deansi by hav-
ing much stronger primary ribs, a slightly wider
umbilicus, a stouter whorl section, and rounder flanks
(pi. 19, figs. 19-27). These features would ordinarily
lie sufficient to justify assigning them to a distinct
s|>ecies. However, the presence at other localities (Mes.
Iocs. 2201, 14484) of 4 specimens (pi. 19, figs. 16-18)
that are intermediate in appearance suggest that the
25 stout, coarsely riblied specimens are merely an ex-
treme. variana of L. deans] (Whiteaves). Their status
cannot lie settled definitely by the specimens on hand.

Figured specimens: l.'SKM 130158. 130162. 13016!), 130174.

Localities: USGS Mes. lm\ 2201. 8872. 8S73. 8878. 9972, 14484.

Genus LEHUR0CERAS Spath, 1942
Lemuroceras talkeetnanum Imlay, n. sp.

Plate 18, figures 34—41

ILcmuraccrax cf. L. indieum Spath. McLearn, 1945, Geol. Sur-
vey Canada Paper 44-17 (2d ed.). pi. 5. fig. 4.

This species is represented bv two specimens that
retain some of the inner shelly layer. O 11 this layer
feather structures is well shown at one place (Arkell,
in Arkell, Kummel and Wright, 1957, p. L92). The
whorls are subquadrate in section and higher than wide

110

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

and embrace about three-fifths of preceding whorl.
The flanks are flattened, but become gently convex on
the body chamber. The venter is nearly flat on the
sutured part of the shell and gently rounded on the
body chamber. The umbilicus is moderately narrow;
the umbilical wall is low and steeply inclined and
rounds evenly into the venter. The body chamber is
represented by half a whorl and appears to lie com-
plete.

The ribbing on the septate part of the body whorl
is prominent, widely spaced, and strongly flexuous.
About half of the ribs arise on the umbilical wall, are
most prominent at the umbilical edge, incline forward
strongly low on the flanks, recurve near the middle of
the flanks, and arch forward strongly on the upper
part of the flanks and on the venter. The remaining
ribs either arise freely near, or below, the middle of
the flanks, or are indistinctly connected with the longer
ril)S at about the top of the lower third of the flanks.
All ribs are equally strong on the venter, and all are
slightly reduced in strength along the midventral line.

The ribbing on the body chamber fades out rapidly
toward the aperture and becomes less strongly arched
on the venter. Near the aperture only weak lines of
growth are visible where the shell is preserved and the
internal mold is quite smooth.

The body chamber has been crushed laterally and
cannot be measured. At the beginning of the body-
chamber, the whorl height is 17 mm, and the whorl
thickness is 13 mm.

The suture line is quite similar to that of L. ahurense.
(Spath) (1933, p. 801, pi. 129, fig. 5) from India. The
first lateral lobe is a little longer than the ventral lobe.
The first lateral saddle is very wide. The other lol»es
and saddles are relatively much smaller. The auxil-
iaries descend slightly toward the umbilicus.

This species is remarkably similar to L. indicum
(Spath) ( 1933, p. 801, pi. 128, figs. 4a, b, 5a, b) from
India and Madagascar (Collignon, 1949, p. 08, 09, pi.
12, figs. 2, 2a, b, pi. 14, fig. 2). It is distinguished from
that sjiccies mainly by being more involute and by its
ribs arching forward more strongly on the venter. It
appears, nlso, to have flatter flanks, but that may l>e a
result of compression. The primary ribs are not nearly
so prominent at the umbilical edge as in the holotype
of L. indicum (Spath), or in the ammonite fragment
figured by McLearn (1945, pi. 5, fig. 4), from the west-
ern interior of Canada, but the ribs are of nearly the
same strength as on the paratype of L. indicum
(Spath) (1933, pi. 128, fig. 5a).

Types: Holoty|>e t'SN.M 13015. Paratype USNM 130150.

Locality: USG8 Mes. loc. 24877.

Lemuroceras? sp. Jut. of. L. dublum Collignon

Plate 18. figs. 26-29

One small specimen has a subquadrate whorl section,
flattened flanks and venter, a moderately wide umbili-
cus, and a low vertical umbilical wall that rounds
evenly into the flanks.

The ribs are strongly flexuous on the flanks and arch
forward moderately on the venter. Most ril>s begin
on the umbilical wall and remain single on the flanks.
About one-third of the ribs bifurcate at, or below, the
middle of the flanks, or are indist inctly connected with
secondary ribs. A few secondary ribs arise freely on
the flanks. The secondary ribs are as strong, or nearly
ns strong, ns the primary ribs. All ribs are slightly re-
duced in strength along the midventral line. Six weak
constrictions are present, but are conspicuous only on
the venter.

At a diameter of 25 mm, the whorl height is 10 mm,
the whorl thickness is 8 mm, and the umbilical width
is 7.5 mm.

The suture line is not preserved.

This specimen is assigned to Lemurocera * rather
than to Leconteites because of the characteristics of its
ribbing, but it does have a vertical wall, a feature
which is characteristic of Leconteites. Its appearance
in lateral view is similar to that of L. dubium Collig-
non from Madagascar (1949, p. 74, pi. 15, figs. 2, 2a,
b), but it has fewer secondary ribs and more primary
ribs jier whorl, is more compressed, and has a vertical
umbilical wall.

Figured specimen: USNM 130157.

Locality: USGS Mes. loc. 14484.

Subgenus STTBARCTHOPLITES Casey, 1954, revised Imlay

Subarcthop/ites Casey (1954, p. Ill) based on Le-
mur ore ms belli McLearn (1945, pi. 3, figs. 17, 18) from
the western interior of Canada was considered by its
author to lie more similar to the boreal genus Arctho-
plites than to Lemurocemx from India and Mada-
gascar. The discovery of adult specimens of Lemuro-
ceras belli McLearn in northern Alaska shows, how-
ever, that it differs from Arctkoplites by lower points
of rib branching, by the presence of constrictions, and
by its ribs fading on the body chamber instead of lie-
coming coarser. In these respects it is identical with
typical species of Lemuroceras from India and Mada-
gascar. Lemuroceras belli McLearn differs from the
typical sjiecies only by having rounder flanks, less
flexuous ribbing, and a less abrupt change in the direc-
tion of ribbing on the lower part of the flanks. These
differences are slight and are not considered worthy of
more than subgeneric rank.

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CRETACEOUS AMMONITES FROM CHITINA VALLEY AND TALKEETNA MOUNTAINS

111

Lemarocerai (Subarcthoplites) aff. L. belli UcLearn

Plate 18. figures 23. 30-33

Two immature specimens of Lemurocerax from the
Chitinn Valley differ from L. belli McLearn (1045, pi.
3, figs. 17, 18; 1948) by being more compressed and by
having weaker ribs that bifurcate less commonly and
are more widely spaced on the venter.

The small specimens from the Chitinn Valley each
have about one-third of a whorl of body chamber. On
the septate part of the shell the primary ribs incline
forward strongly on the umbilical wall and on the
lower third of the Hank where most of them either
bifurcate or are indistinctly connected with a secondary
rib. All ribs curve backward near the middle of the
Hanks and then arch forward gently on the venter.
On the body chamber, furcation becomes less common
and secondary ribs become fewer. All ribs continue
across the venter with only slight reduction in strength
ns compared with the ribs on the flanks.

The suture line has a very wide first lateral saddle
and a wide trifid first lateral lobe that is only slightly
longer than the ventral lobe. The auxiliaries are
curved slightly adorally. The pattern of the suture
is similar to that of L. aburenxe (Spath) (1988, pi.
129, fig. 5) from India.

Figured specimen: U8XM 130131!.

Locality: USGS Mes. loe. 9492.

Arcthopllteif ip.

Plate 18, figures 22. 24, 23

Two fragments bear high, thin, widely spaced ril>s
similar to those on the outer whorl of Arcthopliten
jnehromensix (Nikitin) (1888, p. 57, pi. 4, fig. 1) from
the lower or middle Albian of Russia. On the venter of
the internal mold the ribs arch forward and become a
little broader and lower. In places where the shell is
preserved the ribs are much thicker than on the in-
ternal mold. As the lower parts of the Hanks are not
preserved, the fragments could lie assigned as readily
to Tetralioplite * or Pxeudoxonneratia as to Arctho-
plites.

Figured specimen: I.'SNM 130137.

Locality: USGS Mes. loe. 0402.

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Murphy, M. A.. 1950. Lower Cretaceous stratigraphic units of
northern California : Am. Assoc. Petroleum Geologists Bull.,
v. 40. p. 2098—2119, 0 figs.

Nikitin, S. N.. 1888. lies vestiges de la j^rhsle cretnc4e dans
la Russie centmle: Com. Geol. St. l’eterstmurg. Mom..
v. 5, no. 2. p. 166-205, pis. 1-5, map.

Orliigny. Alcide d\ 1840-1842, I’al6ontologte de Francalse:
Terrains Cretaces. v. 1. 002 p., 148 pis.

l’arona. C. F., and Bonareili, Guido. 18!)7. Fossill Alhiani
d'Kscragnolles del Nlzzardo e della Liguria occidental :
Palueontogr. Itnlica. v. 2, p. 53-112. pis. 10-14.

Pervlnqulere. I... 1!K)7. Etudes de iml&mtologie tunlslenne. I
Cephalopoda* des terrains secondaires. (Carte geol.
Tunisia). Systeme Cretaclque. p. 43-428. pis. 1-27.

Pictet. F. J.. and Roux, W„ 1847-53. Pescrlptlon des mollnsques
fossiles qtii se trouvent dans les gres verts des environs de

Geneve: Soc. phys. et hist. not. Geneve, v. 1, pt. 4, 286 p..
pis. 20-43.

Sinzow. I. T„ 1009. Beit rage zur Kenntniss des siidrusslschen
Aptien und Albien : Verh. russ. k. Min. Gesell. St. Peters-
burg. ser. 2, v. 47. p. 1-48, pis. 1-4.

Spath. L. F.. 1923-1943, A monograph of the Ammonoldea of
the Gault : Palaeontogr. Soc.. 2 v., 787 ]>.. 72 pis.. 248 text
figs., 4 tables.

1927-33. Revision of the Jurassic cephalo[M>da fauna of

Knclih (Cutch) : Palaeontologia Indicn new ser. v. 9,
0 pts.. 945 p., 130 pis.

1930. The fossil fauna of the Semnuu Range and some

neighboring areus: |>art V. The Lower Cretaceous am-
mouoidea : with notes on Albion cephalo|»oda from Hazara :
Palaeontologia Indtca. new ser.. v. 15. p. 51-06. pis. 8. 9.

Stanton, T. W.. 1805, Contributions to the Cretaceous Paleon-
tology of the Pacific Coast, The faunn of the Knoxville
beds: U.S. Geol. Survey Bull. 133. 132 p.. 20 pis. (18961.

Stelck. C. R.. Wall. J. II.. Bnlmu. W. G.. and Martin. L. J..
1956. Middle Albion fornminifera from Athabasca and
Peace River Drainage areas of western Cannda : Resenrch
Council of Albertn Rept. 75. 60 p., 5 pis.. 2 figs.

Uhlig, Victor. 188.3, Die Cephu!oi>odenfauun der Wernsdorfer
Schlchten : K. Akad. Wlss., Math.-naturh. Kl.. Denks. v.
40, p. 1-160 (128 200). 32 pis.

Warren, P. S., 1947. Cretaceous fossil horizons in the Mackenzie
River valley: Jour. Paleontology, v. 21, no. 2. p. 118-123.
pis. 29, 30.

Whlteaves. J. F.. 1876. On some invertebrates from the coal-
I tearing rocks of the Queen Charlotte Islands: Canada
Geol. Survey. Mesozoic Fossils, v. 1, p. 1-92. pis. 1-10.

1889, On some Cretaceous fossils from British Columbia.

the northwest territory and Manitoba : Cannda Geol. Sur-
vey. Contr. to Canadian Paleontology, v. 1, p. 151-196. pis.
20-24.

— 1893a. Notes on the ammonites of the Cretaceous rocks

of the district of Athabasca, with descriptions of four new
s|iecles: Royal Soc. Cannda Proc. and Trans.. 1 ser., v. 10.
sec. 4. p. 111-121. pis. 8-10.

1803b, Descriptions of two new species of ammonites

from tlie Cretaceous rooks of the Queen Chnrlotte Islands:
Cnnndlnn Record Science, v. 5. p. 441-446, pi. 7.

Whltchousc. F. W.. 1928, Additions to the Cretaceous ammonite
faunn of eastern Australia, part 2 ( Desmooerntidue) :
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Algcrmissen : Jahrb. l’reuss. Geol. Ismdesnnstalt u. Berg-
akademie fur 1!H)3. v. 24. p. 22-42. pis. 4. 5.

Wright. C. W.. in Arkell. W. J.. Kummel. Bernhard, and
Wright. C. W.. 1957, Mesozoic Ainmonoidca : Treatise on
Invertebrate Paleontology, part L, Mollusca 4. 400. p..
Ulus.

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INDEX

(Italic number* Indicate description*!

A Page

ahtttentt, l.erjiuroctrat . . . 1 10, 111

affine. Hendantieera*. 105

gtabrum. l)<tmortras IU&

agataizianum. KnotmaUlla 99

akutehaentit, Yaldedoruila .... 10U

olatkana. /'ntahfl 91, OH, 10\. pi. lfl

olaskanum, CaUixomctrat 101

(' allixonieera $ ( lYollemanntetuu) . 91.96,101.

pi. 12

A I him i ammonite*. geoRraphlc distribution vs

A I bun faxinuk* . . 93

a Idertoni. Colli pbflloe era* 91.93.99. pi. ||

Ammonite faunulcs and correlation* Hp-tt

. f mmonite*. . ICO

taeveeri 105

koydenl . .. 106

. l/i<ifaudry<rra« HM. *0. W

OHratlum. . W. 91,96,99. p|. II

up. Indet VI. 9b

anglieu*. hxoaramn* . 91

. I rclkaplifet 8N. 1 10. 1 1 1

)aeAroiii<n#i* . Ill

Up 9I.S&/J/. pi. 18

(. l»/irr«t« deauti. Oleoifepbannt 109

AstieridUeu* 102

. I ueella Mi

cranicollit W

I Kill OH Ml

. I ucettina 99.91.94

AucfUhut up.. . - pi. 10

ournrium. AnagaNdrgerra* ... 89.91.98. 99. pi. II

l.ftoeerat < Kosimatella) . . 9U

Aayfrr. CUonicrrat 108

Bear Creek 88 . 89 . 91 . t*>

hell:, f.emuroeeto* 92.97. 110, Iff. pi. 18

l.cmuroeerat {Subarcihoplitet) 9l.92.98.IH.pl. 18
Henudmnilfttat 88.90.94. las. 106

affine, 106

bretftri 106

glabrum 92.90.08, 105. pi. 16

bulrriftiff 106

laengatum 106

tulSerlandl IQS

(Crantxieerat) .. 88

mulfieounrietu/n 92.9$. /Of. pi. 14

RfUiliinllmiiUnar 88

bicut raloidet, CUonicerat 10$

bitureata, KennieoUia 91

Billy Creek.. . 8*96

Biologic Itn.ll> Mr 87-88

beeverl, Ammonites . 10C

Jteudanticeror 105

Itreu eneerat 91, 92. 94. W, /OS. p|. 17

Hretreticeros 88.83.94.97.105

htttreri 91. 92, 94 ,9*. I0S. pi. 17

faunulC 01,92.97

bn f deni. 91, IM

hiilrnriut 80. 91. 94. 9$. f06. pi. 17

rone 91.92. 94.93

bnllotos. Parosiletilet 91. 98. 106, pi. 18

P«K*

cali/ornicum. Hgpophyllocera*

HI. M. pi. 11

Catlipbylloceras

88,99

alder tom

91. 98, 99. pi. 11

Nitinanum

91. 98, HP. pi. 11

OdlllphyllocCTatlniu-

Callizonierrat

8K.93.Ytl.97. 101. MB. 1113

afartanum. .

101

alaskannm

91. 98. 101, pi. 12

fohllnenu

91. 9«. 101. pi. 12

ketlhaeki

Canyon Cittk

88.89.91,97

cappfl. Kor*malella . .

91.(9. 99. pi. 12

Cepi)alo|Mxi:i

cAiricbeiiti*. PuzoAta

100

Chltlna River .

Cbitina Valley

8K-N9

ehiUnanttm. ChgUapaekreerar

91.97. 98w pi. 11

Chokcuim Hlver

Claiwnyf, bwt».

IDO

Clear water formation..

clean. CteonicYrar . . .

lt»

Cleoaiccra*

88, 92, 94. 108

to fie i

i«

10$

108

109

. 91.98.fON.pl 19

CleonlceratliuM’ .

fomanrAroiiiM. Inoceromu*

Copper River beein

Correlation* and ammonite faumilcs

crostieoUlt, A ueella

ero*nco*taUtt. Ixconleilet . ....
cratsus. SfotfHites

91
88
89- tt

«t.1#k fdf.pl. 14

dm mi. Ixeonleitet . . 91, 91. 98. 109, pi. 19

OfcaifrpAtfNiM iAtlleta ) . 109

Iksmoceras 88.91. 100, MB. lie;

attiur gtabrum 105

nurriami 100

ropi 106

8p. Juv 91, 98. 106, pi. 17

Dewnoceratklae 88. 93

Dcsmocertt lute 88

Ikourillticera* . . . 88. 80. 92

mammilla! nm rone 92

dubium. Ijmtiifxtraa 98. /fO. pi. IN

Flume Oeek,

Fohlln Creek

fdbhnentt. Colli xonicerar

Fn«irth of July Creek . .

Frcboldiccros

Stngulare . ....
f.tunuli'

88.96

88. 89.91. 96
( Wolltma n n terras) . 91.

vs. tot. pi. 12

89.91.96

88.91 JOi

«. 93, 94, 97. 9$. fOf, pi 14

tt-tt

O Page

Cabbioceras 8**

sp . - 98

gainesi, Kanmalello. 99

Cattrofdite* . 92

kingi. - - 97

OastroplIltlM* 88

Gate* formation 92

Geographic- distribution. Alhian ammonite*. ... i*

getulina, Yaldtdot sella . 100

Gibraltar Hill tt

glabrum, lleudanlieerat 92, 93. 98. f 06, pi. 16

Iksmoceras affine 105

Place nticerar 105

Grant Aceras IQS

( Grant zicera*), lieudanlicera j 88

* nullieonstrictum, Heudantlceros . 92. 9H. /Of, pi. 14

Giiadryormtinnc 88

Itarmon shale member. I’racv Rtvef formation.. 92

hagdeni, Ammonite* 106

Ifrctrericeras 91.106

Haplile* drnfafiM rone 89

I lop! it Mae 88.91

houreqi, Yaldedorulla 100

kogeri, Callizonlcera* 101

kulencnse. Ikudantlcero* 106

fireiverieera* 89. 91. 94. 98, 100, pi. 17

lltt Uniter 88k 92. 93, 97, 104, 107

rmM . 91. 98, 104. /Off, pi. IN

l/gpophgUocetQ* KN.

ml Hot men m 91,98. pi. II

onoenre 9$

indieum, Umuroceras 92.93. ICO

indigene*. Melchiwxtt* . 101

Inoctramns 88,91

anglicus 91

coaiunrArauite. 91

irrnfnK. /^n«r«rroi .. . 92.93. 103

irregular it, ynratHailt* .. 91.9N./07, pi. 18

Jachromenti*. AretMoplite* 111

Avi/Aarti. Calli:onietra $ {WoUernannicera*). . 101

Keimlcntt formation 98

Kennlcott Glacier 88.89.96

Kennicott River 9$

Kennlcattia . -88,93.94.102.103

bifornta ui . 9N. 10% 104. pi. 16

riffotu . 91,981 fOd.pl, 16

kingi, (iaHroplite*., 97

Kf**maletln 88,99

atftMrt.'MNUM 99

capprf 91.98,99, pi. 12

gained!...., 99

(Koumalellai anraritim. I.gtoee toj. ........ 99

Kov«mntellinae 8$

KowmatiorratUla*' 83.94

114

INDEX

Pace

Kuskulnna Paw 8*89

Ktukulntia Rim. 88

laere. Ptfekoeerae 01.93. f00.pl. 12

laerigalkm, Iftadanlictta* IQS

I.uklna River 9ft

IcCon/d, Leconte it tt lirJ

UeonUtlt* . R v».oi.vq,ui. !<7.P><Uii

ctauicortatu* SU

<fe*»si W.m<bfW.Dl.l»

f mimic 0! v2

leeontt! mi

SOM v/ 91.92.94

modal "4 89. 9I_. 94. w. If/9, pi- 10

fnunute. 89.91

sp 98

Iftyhtonrnsf, Cltonicer+t. 11»

I.emuroeeias KS. 93. 94. 97. 1£9. Llfl

flbnvNf ! IQ. Ill

fteM 12. 97, 1MI.III.PI. IS

SOM

dttblum .. 98. 1/0, pi. 18

iNdienm 92. 03. 100

Irenenee 92. 93. 103

talkeetnanum JiLAtt, /Oft, pi. 1H

(Subarethopliles) M, W, 93, 9L VI

MU.... yLW.ttt.ii/, pi. is

UjtmetkU* tardefurcata tout jW, 82

Loon River formation 92

L nnatode?stUa 100

I.yioceta* (KaifmaieUa) anrarium

McCarthy Creek. . 88. WO, 91, Wi

M ut an uska formation . 9ft. itt

MrlchiotUe* .. Jlii

indlgrner llll

mtrriamt. Ikemoceran lil)

fflotfufftiii. Cleonleerar XUW

mode At ut, teconteite* SV, 9L 9L ttt, 109. pi. 19.

Sfd&tUt* ... . SX.OI. 03 , m

aasttu .... 88 l&/ 0 f t pLll

tehustur .... UL M, 98, 152* pi* 13

faumilc. 91 -vi

Motwe bur format ion 92

mullieonrtncturt. Heudanlicera* < Grant ziceros) .. 92.

98. m. pi. 14

.Veldilma limestone . m>

Seesllerile* M

Ms Ilia Hinder 8*9I.ta»\9?

Page

nilinanum. CaUiphtlloctta* 9L9H, W,pl. 11

Not Ike win member, Peace River formation .92

OlCMfephamu (. Uttrra ) dennti. Hill

onoente, llfftophyllocerq* 98

0 retbeekl, Clecnleerae Bl.ttt 108, pi. Ill

pollan. A NttUo -hli

PwatUaUtB hs.92,2Li&;

fruiter iu 9l.98.rM.pl. is

irttgulan* 8L 98. t(fi. Dl. 18

Pence River formation, Harmon shale member 92

Xotlkrwln member 92

perrhumithl. Pn:os Ifilta. 89. 1W

PhjrHoeemUdae B 94

PhyUocerutlnae 88

PkyUopecKvctrat 88.97

chitinaunm pi. II

ihaMalfnif 91. tw

there toe VS

PlacenliceraA flahrttm Kki

Pteudohaplcetrot 102. ills

Pit udoleymeriella as

Pie u deton neral la ill

P/rdteerrot £8.100

Inert 9LtKlft7.pl. 13

PtychoceratKlne 88. lit

Pttzema *8 91. 103. 104

otertiits m w to:, pi id

ckitichentit 100

quenHedll Ml

Kutn/Nadrala 193

ip.. .91

sp Intlel 9S

puzotioformt*. Sil tetter. nil

PuzMigtlln 8*89.91-93.94. 97. 108

faunule ... va *>i

perrimnuthi 89.98

roqrrri. ffi.1fi.mpl a 19

tatfi B 98

5|>P sy 94

Purostinac. *s

Queen Charlotte Islands

quenrledti. Ptt zotim

rretidei. Unit nit a

rahnrtut, Mofftttier.

roqtrri. Puzcri fella

.Son nr Alfa

rtifopa. Kennlcottio

88.91,93. 190

91- Vv HM. 107. pi. IS
. 91,91. OK. Iii2.i>l. U
.... 89. W. IQS. Dl. 19

198

.... 91. 9*. 103. til. IS

8 Page

ituut alenre, PhyUopachuttra* 9l.9*i

Sil/riltt S9. It)6. 107

puzcelafonnlB 107

rnlpt* 107

SlU^itldue 8s 94

.wnqulare. FuMdiceraM 92. 93, 91 . 97. lOl. pi. 11

Slatka Creek 5S

Xonnraffa refer** His

Stratigraphic nummary 88-89

SudtfdhopttUM .92 .nil

(SnbardkapWe*) belli. Lemuroetrat 91. 92.

Umurocerar xs. 92 93. 9*. 97

nthquadraia, Pttzoria 193

Summary of results 93-97

puthrrlandi, lltttdanlieetas 105

Systematic deecrlpt Iona 97-m

taffi, Puzoriftlla

Talkeetna Mountain.*

tQlkeetnonttm. f.ernuroce/ar . .

Tetragonltu

tim'jtheanui

»P

S|). In<let

Tetrngonltldae

Tetragon Ulnae

Tetrahoplitee

(tier e*ne. Phyllopachyeereu

thnothe/jnue, Tttr/tqonitr *

Trail Creek

m. w

... 98.98. pw p|. 13

BA MO

... 01.98w lQ0.pl. 12

88.94

III

... yi.tcs. too, pi .12

91.9f»

Valdedoettlla

akhrebaenels lit*

gtlulina KO

hourtql 1111

vSitetWAi 91.98. /ft?, pi. II

coyi, Ikamocera* ICtt

rulptA. SiltAitfA lflT

white areri. ValdedatMlln 91. ML IW. pi. 11

irof/tmann terras 101

( Welle mnnNlceraa) nhAknnnm, Cdlllzonlcerae . .. 91.

1K./0/. Pi. 12

OilUionletroe 9J

(oMinense, Caltizonieeras /(?/. pi. 12

JMMmMi CWHtORlffm . ini

Young Creek 8». *9. 91. 9ft

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PLATES 11-19

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PLATE 11

(Figures nn’M-al size unless otherwise indicated]

Figures 1-5.

6 - 12 .

13-17.

18. 10, 24.

20-23, 25-28.

29.

Phyllopachyceras chitinanum Imluy, u. sp. (p. 97).

Holotype USXM 130142, from USGS Mcs. loc. 9492. Suture line drawn from adnpical end of body chamber.
Calliphylloceras nitinanum Imluy, n. sp. (p. 99).

All specimens from USGS Mcs. ioc. 9492.

6, 10, 11. Paratype USKM 130139a.

7, 8. Holotype USXM 130138.

9. Paratype L'SNM 130139b.

12. Paratype USNM 130139c.

Calliphylloctra * cf. C. alder xoni (Anderson) (p. 99).

All specimens from USGS Mes. loc. 9972.

13. Specimen USXM 130161a showing traces of finely ribbed shell.

14. Specimen USXM 130161b.

15-17. Ventral, cross section, and lateral views of specimen USXM 130161c.

Anayaudryccras aurarium (Anderson) (p. 99).

Doth specimens from USGS Mes. loc. 14485.

18, 19. Immut urc septate specimen, L'SXM 130154a.

24. Adult specimen USXM 130154b showing fine striations on the shell and deep constrictions on the mold. Body
chamber represented by three-fifths of a whorl.

ValdtdoneUei ? whileavai Imluy, n. sp. (p. 100).

Both specimens from USGS Mes. loc. 9492.

20-23, 25. Holotype, USXM 130145. Suture line drawn at diameter of 11.5 mm. Xote figures 21 and 22 arc
identical views at different magnifications.

26-28. Paratype USXM 130146.

Ilypophyllocera i cf. //. californicutn (Anderson) (p. 98)

Specimen USXM 130132, from USGS Mcs. loc. 9492.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 36« PLATE 11

PH YLLOPA Cll YCERA S, ( 'A LUPH YLLOCERA S. A XA GA UDRYCERA S,
VA l.DEDORSELLA AND H YPOl 'H YLLOt ERAS

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PROFESSIONAL PAPER 351 PLATE 12

ca i.i.i/oxk i:iia s. koss.ua mu. a, rru no< 'kha s. a n i> mm a coxitis

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PLATE 12

natural Site unh*v< othcrwlst imlic»tc<l|

Floruits 1-10.

11-16.

17-22.

23.

21-28.

Catlitoniceras ( Wollemanniceras ) fohlintnte Imlay, ». sp. (p. 101).

All specimens from USGS Mes. loc. 14484.

I. 2, 10. Holotype USN M 130155.

3. Paratypc U8NM 130156a.

4, 5. I’urutype USNM 130156b.

6. Para type L'SNM 130156c. Weaker ribbed than (he holotype.

7-9. Paratypc USN M !30156d. Stronger ribbed than the holotype.
Callizoniceras ( Wollemanniceratt ) alazkanuin Imlay, n. sp. (p. 101).

Both parntvpes from USGS Mes. loc. 8873.

II, 12. Holotype USNM 130165, from USGS Mes. loc. 9976.

13, 14. Paratypc USNM 130160a.

15, 16. Paratype USNM 130166b.

Kossmatclla cappsi Imlay, n. sp. (p. 99).

Both paralypes from USGS Mes. loc. 9492.

17, 19. Paratypc USNM 130140a.

21, 22. Paratype USNM 130140b.

18, 20. Holotype L’SNM 130160, from USGS Mes. loc. 14514.

Ptychocera* cf. P. lanv (Gahb) (p. 100).

Specimen USNM 130163, from USGS Mes. loc. 9972.

Tctragoniten n(T. T. timothcanus (Pictet) (p. 100).

Both specimens from USGS Mes. loc. 9492.

24, 28. Adult showing three-fifths of a whorl of body chamber, USNM 130131a.
25-27. Immature specimen USNM 130131b.

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PLATE 13

(Ftcurr* natural #fctr units* odKtwtv lndir;tlr<l|

Figi'RKS 1-13. Moffitites robiislus Irnlay. (p. 102).

1-3, 5. Septate paratype USXM 120875a, from USGS Mrs. loc. 9072, is slenderer than most specimens of the
species.

4, 9. Small septate paratype USXM 120876a, from USGS Mes. loc. 14485.

6-8. Normally stout septate paratype USXM 120875b, from USGS Mes. loc. 0072. Note tendency of ril>s to
become threadlike on the venter.

10, 13. Holotypo USXM 120874, from USGS Mes. loc. 2101. About three-fifths of a whorl belongs to the body
chamber.

11. 12. Lateral views of paratype USXM 120876b, from USGS Mes. loc. 14485. Shows characteristic ribbing
on inner whorls.

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PROFESSIONAL PAPER SM PLATE 13

MOFFITITES ROBUSTUS

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER PLATE 14

•

< Y

r ) l

1 1
L

REV DA ET1C ERA S, MOFFIT1TES. A N D FREUOLD1 CERA S

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PLATE 14

I Figures iwuiriil flip unlrew othpr»l*o lndleatr<l|

Ficuaes 1, 2. Heuclanliceras (Grantziceras) mulliconslriclum Imlay (p. 105).

Holotype VSNM 128721, from USGS Mes. loc. 24877.

3-7. Mnffititen, crastus Imhiv, n. sp. (p. 102).

3, 4. Paratype USXM 130176, from I’SGS Mes. loc. 14487.

5-7. Holotype USXM 130175, from U8GS Mes. loc. 8878.

8-17. Frtboliliccran tingulare I in ley (p. 102).

All specimens from USGS Mes. loc., 24877.

8-10. Lateral views and suture line of paratype USXM 120860a.

11, 12, 15-17. Holotype USXM 120868. Xote fine striations on shell. Suture line drawn at whorl height of 15
mm.

13. Paratype USXM 120860b.

14. Paratype USXM 120860c. The smooth body chamber occupies about three-fifths of a whorl.

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PLATE 15

(Figure* natural site unless otherwise Indteutcitl

FiaURES 1-0. Keiinicottia hi/urcata Imlay (p. 103).

1-5. Holotype USNM 130870, from USGS Mes. loc. 0072. Suture line drawn at diameter of 03 mm.
0. Paratype USNM 120871, from USCJS Mes. loc. 8873. Shows furcation of ribs on inner whorls.
7-13. KennicoUia ntyosti Imlay, n. sp. (p. 103).

7, 8, 11. Paratype USNM 130153a, from USGS Mes. loc. I ll 85.

0, 10. Paratypc USNM 130153b, from USGS Mes. loc. 11185.

12, 13. Holotype USNM 130152, from USGS Mes. loc. 0480.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER :im PLATE 16

KKXXICOTT1A MFURCATA AND K. HUGOS A

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 354 PLATE IS

PUZOSIA AL ASK AS A AND HKVDA NTH' ERA S V,LA HR CM

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PLATE 16

|VI*ures natural site unless otherwise Indlcatnll

ICUHKH 1-13. Puxotia alaskana Imlay, n. sp. (p. 104).

1-4. Ilolotype USNM 130143, from U8GS Mes. loc. 04512.

5-13. Para types USNM 130144, from U8GS Mes. loc. 51402. Lateral views 8 to 13 shows differences in strength
of ribbing and in constrictions. The suture lines were drawn from the s|>ecimcn shown in figure 5.

14-21. Heiirtanlicerag glabrum (Whitenves) (p. 105).

Plesiotypcs USNM 130140, from USGS Mes. loc. 24877. Figures 14 and 10 represent fairly smooth specimens.
Figure 15 represents a specimen with large bulges or ribs. Figures 1G to 18 show prominent constrictions.
Figures 20 and 21 represent a specimen that develops weak lateral bulges. All these specimens are septate.

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PLATE 17

insures natural site unless otherwise Indicated]

Fiocres 1-4. De&mocerae? sp. juv. (p. 106).

Specimen USNM 130135, from USGS Mes. loc. 9492. Siitnre drawn at whorl height of 10 mm.

5-10, 12, 13. fircuericcras breweri (Gahb) (p. 105).

Plesiotypes USNM 130133, from USGS Mes. loc. 9492. Figures 5-7 represent a typical specimen. Figure 8
illustrates feather structure on the septate part of the shell and likewise bears ribbing typical of the species.
Figures 9 ami 10 and figure 13 represent two s|>ecimcus in which coarse ribbing appears nt an earlier growth
stage than is typical in the species. The suture line was drawn at the adapical end of the body chamber from
the specimen shown on figures 5-7.

11, 1 4—1 6. lirewerictras cf. H. hulentnse (Anderson) (p. 106).

11. Specimen USNM 130159, from USGS Mes. loc. 11514.

14-10. Specimens USNM 130130, from USGS Mes. loc. 9492.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER :(S4 PLATE 17

Dt'SMOCh'HA S ? Si'.. HUE WE UK ERA N BKEWKM. AND />'. HI’LKSSK

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 3M PLATE 18

PA RASILEStTES, HULE'.XfTES. A RCT HOP LITE'S?. A\'I> EEMUKOCEHAS

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PLATE 18

(Figures natural sire units* othtrwist iixltam-tl)

FlGl'RES 1-8. Parasilciiles bullatus Imlay (p. 10(1).

1—1, 8. Holotvpo USNM 120872, from USGS Mes. loc. 9402.

5-7. Paratype USNM 129873, from USGS Mcs. loc. 9492.

0-17. Parasilesitex irregularis Imlay, n. sp. (p. 107).

All types are from USGS Mcs. loc. 9402.

0-11, 16, 17. Lateral, ventral, and apertural views and suture line of liolotype USNM 130147. Suture line drawn
at diameter of 13 mm. Note that figure 1 6 is an enlargement of figure 9.

12, 13. Paratype USNM 130148a.

14,15. Paratype USNM 130148b.

18-21. little nitre cf. //. reesidti (Anderson) (p. 107).

Specimens USNM 130134, from USGS Mcs. loc. 0402.

22, 21, 25. Arclboplitex ? sp. (p. 111).

Specimen USNM 130137, from USGS Mes. loc. 9402. Figures 24 and 25 represent, ventral and lateral views of
one specimen.

23, 30-33. I^eintirocera* (Subarclhoplilex) aff. L. belli Mci/carn (p. 111).

Hot h specimens from USGS Mes. loc. 14484.

23, 30-32. S|H'cimen USNM 1301 3Cu. Suture line drawn at diameter of 10 mm.

33, Specimen USNM 130136b.

26-29. Lemuroceras! sp. juv. cf. L. dubium Collignon (p. 1 10). Specimen USNM 130157, from USGS Mes. loe. 14484.
34-41. Lemurocerax talkcelnnnum Imlay, n. sp. (p. 100).

34, 37-30. Holotype USNM 130151, from USGS Mes. loc. 24877. Suture line drawn at whorl height of 14 mm.

35, 36, 40, 41. Paratype USNM 130150, from USGS Mes. loc. 24877.

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PLATE 19

I Figure* imutal sin- unless otherwise ladlcMed)

FlOfRES 1-3.

1 - 1 ).

7-14.

15-27.

28-32.

33-35

30-39

Leeontcitcx teconiei (Anderson) (p. 109).

Plesiotypc USNM 130171, from gulch emptying into Ihilrn Creek a little east of Ono, Calif. Inserted for
comparison with species of Lcconteiles from Alaska. Note tubercles at umbical edge.

LcconUitex modtxtnx (Anderson) (p. 109).

•1, 5. Plesiotypes USNM 130172, from USGS Mes. loc. 9971.

G. Plesiotypc USNM 130173, from USGS Mes. loe. 11389.

Leconte ilex dcanxi (Whiteavcs) (p. 109).

7, 8. Plesiotypc USNM 13010-la, from USGS Mes. loc. 9972.

12-14. Plesiotype USNM 1301041), from USGS Mes. loc. 9972. Suture line drawn at whorl height of 10.5 mm.
9-11. Plesiotype USNM 130170, from USGS Mes. loc. 2201.

Leeontcitcx cf. L. dcanxi (Whiteavcs) (p. 109).

15, 20, 21. Specimen USNM 130102a, from USGS Mes. loc. 9972.

10, 17. Specimen USNM 130158, from USGS Mes. loc. 14484.

18. Specimen USNM 130109, from USGS Mes. loc. 2201.

19, 23, 24, 27. Four specimens USNM 130174, from USGS Mes. loc. 8872. These show changes in ribbing during
growth.

22. Specimen USNM 130102b, from USGS Mes. loc. 9972.

25, 20. Specimen USNM 130102c, from USGS Mes. loc. 9972.

Auteltina sp. (p. 91).

Both specimens from USGS Mes. loc. 8873.

28-30 Left and right valves and anterior view of both valves of an average-sized specimen, USNM 130107a.

31, 32 Left and right valves of a large specimen, USNM 130107b.

I'niosigclla cf. /*. rogerxi (Hall and Ambrose) (p. 108).

Three specimens USNM 130108, from USGS Mes. loc. 8877, show changes in ribbing during growth.

Clconicerax ocerbecki Imlay, n. sp. (p. 108).

llolotypc USNM 1301 11, from USGS Mes. loc. 9492. Note elongate tubercles at umbilical edge.

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mUAV

GEOLOGIC A I. SURVEY

PROFESSIONAL PAPER 3M PLATE IS

L EC OS T El T ES. AlCELLINA. PUZOSIGELLA. AND CLEON1CERAS

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Interpretation of the Composition
of Lithium Micas

By MARGARET D. FOSTER

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 3S4-E

Relations of lithian muscovites ana
lepidolites, and of siderophy Hites,
protolithionites, zinnwaldites, and
lepidolites, based on published analyses

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : I960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.

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CONTENTS

p **•

Abstract ... 115

Introduction 115

Calculation of formulas 115

Aluminum lithium micas 116

Interpretation of composition of lepidolites based on

end members 116

Compositional changes shown by the analyses...... 117

Hypothetical Li- (octahedral Al) replacement ratios.. 117
Relation of Li to other constituents in calculated

formulas ... ... 119

Relation between Li and octahedral AL. 119

Relation between (Li— R +J ) and Si 121

Relation between Li and total Al 121

Relation between Li and occupied octahedral

sites in excess of 2 . 00 ......... ........ 122

Relation between LijO and F 122

Relation between LitO content, octahedral occu-
pancy, and structure .................. 122

Discussion ....... 126

Ferrous lithium micas 127

Previous interpretations of composition 127

Compositional changes shown by analyses 129

Ftn

Ferrous lithium micas — Continued

Relation between ferrous lithium micas, sidero-

phyllites, and aluminian lepidomelanes 129

Compositional relations in eiderophyllites and ferrous

lithium micas 130

Relation between Li and trivalcnt octahedral

cations • 130

Relation between Li and Fe + * 130

Relation between Li and Si 131

Hypothetical Fc +, -I.i replacement ratios 131

Sldcrophyllite-lepidolite isomorphous series 132

Siderophyllites and lepidomelanes 134

Protolithionites... 136

Zinnwaldites 136

Ferroan lepidolite (cryophyllite) 136

Relation between aluminum lithium micas and ferrous

lithium micas .... 137

Unusual lithium micas 139

Summary... ......... 140

References cited 141

Index .......... 147

ILLUSTRATIONS

Fionas 25. Relation between octahedral sites occupied by Li and vacated by Al in aluminum lithium micas 120

26. Relation between (Li— R +J ) and Si in aluminum lithium micas 121

27. Relation between the number of formula sites occupied by Li and R+* in aluminum lithium micas 122

28. Relation between Li and octahedral occupancy in excess of 2.00 in aluminum lithium micas 123

29. Relation between LijO and F in aluminum lithium micas 123

30. Relation between F and HjO+ in aluminum lithium micas 123

31. Relation between Li occupancy, octahedral occupancy, and structural type in Stevens’ and Berggren’s samples. 125

32. Histograms of selected formulas showing the relation of lithian muscovites and lepidolites 127

33. Relation between Li, R +, (Fe +, I Mn +1 , Mg), and octahedral R + * (Al, Fe +, ) + Ti +4 in aluminum lithium micas 128

34. Relation between Li and octahedral R + * cations in siderophyllites and ferrous lithium micas ........... 130

35. Relation between Li and Fe +J in siderophyllites and ferrous lithium micas 130

36. Relation between Li and Si in siderophyllites and ferrous lithium micas 131

37. Relation between Li, R +, (Fe +1 , Mn +I , Mg), and octahedral R +, (A1, Fe +, ) + Ti + * in siderophyllites and ferrous

lithium micas 131

38. Histograms of selected formulas representing steps in the siderophyllite-lepidolite series 134

39. Relation between Li, R +1 (Fe+*, Mn 41 , Mg), and octahedral R + *(A1, Fe +, J + Ti' H in lithium micas 138

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CONTENTS

TABLES

p«i

Tablb 1. Relation between Li,0 content, octahedral occupancy, and structure of lithium micas analyzed by Stevens 124

2. Comparison of Li occupancy, Li-(octahedral Al) replacement ratio, and structure 126

3. Selected formulas illustrating relation between lithian musoovites and lepidolites 126

4. Selected formulas representing steps in the siderophyllite-lepidolite series 133

6. Analyses of lithian micas that do not fit in the aluminum lithium or ferrous lithium series 139

6. Analyses, with data for writing formulas, of aluminum lithium micas used in interpretation of composition (in

order of increasing Li,0 content) 142

7. Analyses, with data for writing formulas, of siderophyllites and ferrous lithium micas used in interpretation of

composition (in order of increasing Li,0 content) - 144

8. Analyses, with data for writing formulas, of siderophyllites and ferrous lithium micas not used in interpretation

of composition (in order of increasing LijO content).. 146

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

INTERPRETATION OF THE COMPOSITION OF LITHIUM MICAS

B3' Margaret D. Foster

ABSTRACT

A study of more than 100 analyses of lithium micas reported in
the literature indicates that, compositionally, most of the lithium
micas may be interpreted as if derived by isomorphous replace-
ment from muscovite or sidcrophyllite.

Starting with muscovite, analyses and formulas of aluminum
lithium micas, arranged in order of increasing Li content, are
characterized by decrease in octahedral A1 and in tetrahedral A1
and by increase in Si and in octahedral occupancy. These
changes can be interpreted as the result of progressive replace-
ment of octahedral A1 by Li, in ratios varying between 2 and 3
Li for 1 octahedral Al. The aluminum lithium micas are not,
however, members of a continuous isomorphous scries. The
scries is interrupted about halfway between an octahedral occu-
pancy of 2.00 and 3.00 by a change in structure from muscovite
to lopidolite. The term "lithian” muscovite is given to aluminum
lithium micas having a muscovite structure.

Starting with siderophyllite, or other trioctahedral micas
having high Fc** and very low Mg content, analyses and formulas
of ferrous lithium micas, arranged in order of increasing LI
content, are characterized by decrease in Fo* 1 , decrease in
tetrahedral Al, increase in Si, and increase in octahedral occu-
pancy. These changes can be interpreted as the result of pro-
gressive replacement by Li* 1 of Fe**, at an average replacement
ratio of 2.0 Li* 1 for 1.5 Fe**. As there is less difference be-
tween the number of positive charges carried by the replac-
ing cations and the replaced cations than in the aluminum
lithium micas, the change in composition and the increase in
octahedral occupancy Is less in the ferrous lithium micas. The
prototype, siderophyllite, Is structurally trioctahedral, and, as
replacement tends to increase octahedral occupancy, the ferrous
lithium micas are also trioctahedral and no structural adjust-
ments are necessary. The ferrous lithium mica series is, there-
fore, not broken as is the aluminum lithium mica scries. Varietal
definitions based on octahedral sites occupied by L1+ 1 in the half-
cell formula are: lithian siderophylite, having fewer than 0.25
sites occupied by Li* 1 , protolithionlte, having between 0.25 and
0.75 sites occupied by Li +I , zinnwalditc, having between 0.75
and X.25 sites occupied by Li* 1 , and lepidolite, having more than
1.25 sites occupied by Li* 1 .

The high-Li members of both scries aro lepidolites. Thus
lepidolites may be interpreted as if derived from muscovite or
from siderophyllite.

INTRODUCTION

This study of tho compositional and layer-chargo
relations of lithium-bearing micas is an extension of
similar studies by the writer of the compositional and

layer-charge relations of the dioctahedral potassium
micas (Foster, 1956) and of the trioctahedral micas
(Foster, 1960). In the study of the dioctahedral potas-
sium micas, the effect of octahedral replacement of tri-
valent by bivalent cations on the charge relation and
composition of the constituent layers was studied in
detail, and it was shown that these micas can be classi-
fied and correlated on the basis of the relation between
the charges on their tetrahedral and octahedral layers,
and that these micas are members of, and form, a trisi-
licictetrasilicic series. In the study of the trioctahedral
micas, the effect of octahedral replacement of bivalent
by trivalcnt cations on the charge relations and composi-
tion of the constituent layers was studied in detail and
it was shown that the trioctahedral micas accommo-
date the additional number of positive charges carried
by trivalcnt cations, compared with bivalent cations,
in two quite different ways, and that the phlogopites,
biotites, siderophyllites, and lepidomclanes form a
complete magnesium-replacement system, in which
Mg 42 is gradually and completely replaced by bivalent
and trivalent cations.

It is the purpose of the present paper to present a
similar study of the composition and layer-charge
relations of the lithium micas.

CALCULATION OF FORMULAS

For the present study about 80 analyses of aluminum
lithium micus and about 45 analyses of ferrous lithium
micas were collected from the literature, and formulas
were calculated from these analyses by the method
devised by Marshall (1949, p. 58) and modified by the
author. This method is described in detail in a previous
paper of this scries (Foster, 1 960) . Most of the discus-
sion of the compositional characteristics of thes-
analyscs in the present paper is based on the calculated
half-cell formulas.

Attention is directed to tho order in which the groups
and the cations within the group are written. First the
octahedral group, enclosed in parentheses, is written,

115

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116

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGT

with the cations in that group noted in order of decreas-
ing valence (except Ti, which is written after Al). Then
the tetrahedral group, also enclosed in parentheses, is
written, again with the cations noted in order of de-
creasing valence. Above each group the charge is
written. After these two groups, which indicate the
cationic composition of the layers, the anionic compo-
sition, O| 0 (OH,F) 3 , is written and the whole is brack-
eted, thus indicating the composition of the composite
layer. After tho upper part of the closing bracket, the
total negative charge on the composite layer is noted.
This is followed by a notation in parentheses of the in-
terlayer cation content, with the positive charge carried
by these cations written at the top of the closing
parenthesis, and the total number of positions occupied
by these cations written at the bottom. The interlayer
cations are written last, rather than first, which is the
more conventional position, because the amount and
charge of the interlayer cations are dependent on and
must neutralize the charge on the composite layer.

The negative charge on the composite layer and the
positive charge on the interlayer cations should be close
to 1.00 in the half-cell formula. In evaluating the
dependability of the formulas used in this study a
variation of plus or minus 0.10 was permitted in these
values. Formulas in which the negative charge on the
composite layer and the interlayer cationic charge were
greater or less than 1.00 by more than 0.10 were not
used in the study unless the number of sites occupied
by the interlayer cations was less than 1.10. For
example, in a few formulas the negative composite-
layer charge and the interlayer cationic charge were
greater than 1.10, but because of the presence of bi-
valent interlayer cations (Ca), the number of interlayer
sites occupied was less than 1.10. Such formulas were
included in the study. The analyses of aluminum
lithium micas that were used in the study and data
from which their calculated formulas can be written
are given in table 6, in order of increasing lithium
content, and analyses of the ferrous lithium micas used
in the study, with data for writing their calculated
formulas, are given in table 7.

Some analyses of ferrous lithium micas were not used
in the study. In most of these analyses, which are
given in table 8, the alkali content is high compared
with tho octahedral and tetrahedral cations; in the rest
it is low. These discrepancies may be due to faulty
analysis, particularly failure to determine lithium prop-
erly, or to nonhomogencous or contaminated samples.

Any error in the Li determination has a double
effect, as Li is an octahedral cation and the other
alkalies are interlayer cations. If the Li is not com-
pletely separated, tho part not separated is reported as
Na; thus the Na reported is too high, the ulkalies

calculated as interlayer cations are also too high, and
the octahedral cations are too low. If tho determina-
tion of Li errs on the high side, the other alkalies
reported are too low, and the octahedral cations are
too high. If the sample is not homogeneous, it is pos-
sible that the part taken for determination of the
alkalies might be higher or lower in alkalies than the
part taken for determining the other constituents, SiO a ,
AljOj, FejOj, and MgO.

ALUMINUM LITHIUM MICAS

INTERPRETATION OP COMPOSITION OF LKPIDO-
I.ITES BASED ON END MEMBERS

In recent years, following Stevens (1938) and
Winchcll (1942), there has been a strong tendency to
interpret lepidolites as isomorphous mixtures of various
end members. Stevens found that the composition of
the 17 samples upon which he based his study closely
approximates that of isomorphous mixtures of poly-
lithionitc,

(All.tol.ij.aj/SMhofOIOjKi.oj,

with biotite,

lithium muscovite,

(Al,j»LI,j.)<8iMAl|.^)OH(OH) t K|j h
and muscovite,

Alj.oo(Si..#> Ali.«o) 0,j(OH) »K| Ml

Stevens considered that in such solid solutions the end
members would not bo present as individual end-
member unit cells, but that the ions of which the end
members are composed would be distributed uniformly
tliroughout the structure. The selection of end mem-
bers to interpret the composition of lepidolites is an
arbitrary one. As Stevens (1938, p. 023) remarks:

Other combinations of four end members which express the
compositions equally well arc: polylit hionitc, zinnwulditc (assum-
ing its formula to bo K-Lill"Al-AISijO|«Fj), lithium muscovite,
and muscovite; polylithionile, tacuiolitc (K-LiItj"-Si«0| S F,), lith-
ium muscovite, and muscovite. In addition, 6 or 6 of the
above end members may be taken, depending on what end
members are used to express the bivalent ion cont<nt.

Winchell (1942) interpreted lepidolites as isomor-
phous mixtures of polylithionite, paucilithionite (iden-
tical with Stevens' lithium muscovite), and proto-
lithionite (KjLiFctAljSijOxF,). He calculated 28 lithium
micas to these end members and found that LijO was
deficient in all but 1 and that the average deficiency
in LijO was almost 1 percent by weight (0.91). How-
ever, if Borne muscovite was assumed to be present also,
the deficiency in Li t O could be eliminated and the

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INTERPRETATION OP LITHIUM MICAS

117

composition satisfactorily explained. Winchell con-
sidered muscovite to be present, not in solid solution
but as a discrete mineral which might be so intimately
intergrown or intermixed as to be difficult to detect
optically.

Lcpidolite and muscovite are, indeed, often intimately
associated. In Stevens’ study of lepidolites, five
samples are discarded because small flakes of lepidolite
in them were found to contain minute inclusions of
muscovite. Winchell believed that muscovite may
coexist with lcpidolite in units too small to be detected
optically. Ginzburg and Berkhin (1953) believe that
considerable lepidolite in pegmatitic rocks has been
derived from mctasomatic replacement of muscovite
and biotite. By incomplete replacement reactions,
heterogeneous mixtures of the primary mica with
lepidolite have been, they bolieve, analyzed as one mica
type. Pale-violet lepidolites from muscovite in peg-
matites from the Kalbinsk Chains, or from Turkestan,
often contain relict inclusions of muscovite and intimate
graphic intergrowths with this primary muscovite.
However, the amount of muscovite that Winchell had
to assume to be present to account for the deficiency
in lithium content — more than 10 percent in 20 out of
28 samples — is such that its presence could easily be
detected by X-rays. For example, Stevens’ sample 8
(36, table 6), with an LijO content of 5.11 percent, was
estimated by Winchell to contain 29.9 percent mus-
covite. X-ray study by Hendricks and Jefferson (1939)
of this sample showed it to have a one-layer lepidolite
structure. They did not report the presence of any
muscovite in this sample nor in any other of Stevens’
samples that had more than 5 percent of LijO. They
found, however, that Stevens’ sample 1 (21, table 6),
with a LijO content of 2.70, was structurally a mus-
covite. They found samples 2-5 (22, 23, 24, and 29,
table 6), too fine grained for study. Later stud}' of
X-ray and Weissenberg photographs by I xs vinson (1953)
confirmed Hendricks and Jefferson’s findings with
respect to Stevens’ samples. In addition Levinson
showed that Stevens’ samples 2-5 were mixtures of
2-laycr muscovite and 6-layer lcpidolite. These studies
of the crystal structure of lepidolites show that de-
ficiency of Li in them, as compared with end members,
cannot always be explained by assumption of ad-
mixture with muscovite. It is probable that some
materials that have been analyzed as “lepidolites” have
contained some occluded or interlayered muscovite,
but the work of Hendricks and Jefferson and I xi vinson
demonstrates that lepidolites have characteristic optical
properties and structures, and that they are not mix-
tures of end members as interpreted by Winchell and
Stevens.

COMPOSITIONAL CHANGES SHOWN BY THE
ANALYSES

The analyses given in table 6 indicate a general
increase in SiOj content, decrease in Al a O| content,
decrease in H a O+ content, and increase in F content
with increase in LijO content. Some of the analyses
in which LijO is very low have only 45 percent or even
less of Si0 2 , as compared with SiOj contents of more
than 55 percent in those in which LijO is high. On
the other hand, analyses which are very low in LijO
content have the highest amounts of Al, more than 35
percent, whereas those highest in LijO content are
lowest in A1 S 0 3 content, some having only 15 percent
or even less. Similarly, analyses very low in LijO
content have a II 2 0+ content of 4 percent or more but
a low content of F, less than 0.5 percent, and analyses
that contain high amounts of LijO are very low in
HjO-f , 0.5 percent or less, but have high contents of
F, 8 percent or more. These relations are reflected in
the data for the calculated formulas which are included
in the table. These formulas indicate also that octa-
hedral occupancy increases from about 2 sites in alum-
inum lithium micas very low in LijO to about 3 sites
in those containing the highest amounts of LijO.
These, in general, orderly compositional variations
accompanying increase in LijO content suggest the
sort of isomorphous substitution that characterizes
other members of the mica group, such as the substitu-
tion of bivalent and other trivalent ions for aluminum
in the muscovites (Foster, 1956) and the substitution of
trivalent and other bivalent cations for magnesium in
the phlogopites and biotites (Foster, 1960, p. 16-32).
A similar replacement system umong the aluminum
lithium micas was suggested by Levinson (1953, p. 88)
on the basis of his work on the structure of the micas.

HYPOTHETICAL LI-(OCTAHEDBAL AL) REPLACE-
MENT RATIOS

Theoretically, Li can be accommodated in muscovite
micas in 4 different ways: occupancy of vacant octa-
hedral sites, replacement of 1 ion of Al by 1 ion of
Li, replacement of 1 ion of Al by 2 ions of Li, and
replacement of 1 ion of Al by 3 ions of Li. The first
3 methods of accommodation necessitate layer-charge
readjustments, Li being univalent and Al trivalent;
the fourth method does not, as the 3 positive charges
carried by 3 Li ions exactly balance the 3 positive
charges of the replaced Al ion. However, it does neces-
sitate increase in octahedral occupany, as do also the
first and third methods.

In attempting to explain a form of muscovite having
as much as 3.3 percent of LijO, Levinson (1953, p. 93)
speculated as to whether it is possible for such a large
amount of IJ to replace Al isomorphously in the

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118

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

muscovite structure. He concluded that because of
similarity in atomic radii, Al=1.43 A (angstrom units),
Li=1.51 A, the substitution is possible but not neces-
sary as Ii could occupy vacant octahedral positions.
The effect of this sort of accommodation of Li can be
illustrated by Stevens’ (1938, p. 615) sample 1 (21,

table 6), which Levinson found to have a normal
muscovite structure and which contains 2.70 percent of
LijO. This amount of LijO is equivalent to 0.73
octahedral positions in the calculated formula. If this
number of vacant octahedral positions in the primary
muscovite formula

-0.15

-0.85

[(Al,., 4 Feotg 1 Feo^M 8o . 0 iMD 0 t?,)(3i,,, t Al 0 . M )0,o(OH,F)j- |00 K,^^ 0<) ,

J.00

which has the same bivalent-ion content as Stevens’ sample, were to be occupied by Li, with no replacement
of Al,

[ (Ali.> 4 FectoiFe^o 1 M8a.o|Mn^* t Lio. ra ) (Si}.oAli i M)Oio(OH,F);] Kj^ob 05 ,

i?5

certain other changes in layer-charge relations and in
the composition of the tetrahedral layer necessarily
follow. The addition of 0.73 positive charges to the
octahedral layer changes the negative charge of 0.15
previously on that layer to a positive charge of 0.58.
This positive charge on the octahedral layer requires
an increase in the negative tetrahedral charge to 1.58,
by increase in Al content and decrease in Si content,
in order to preserve the total composite-layer charge
at —1.00. Thus a lithium-containing muscovite in
which Li merely occupies vacant octahedral positions
would, in general, bo characterized by a positive octa-
hedral charge and a negative tetrahedral charge in
excess of 1 .00 by an amount equivalent to the positive
octahedral charge, by a decrease in Si equivalent to the

increase in negative tetrahedral charge, and by a 1:1
relation between the number of positions occupied by
Li and the increase (above 2.00) in occupied octahedral
positions. These characteristics are quite different
from those shown by the calculated formulas. As
illustrated in figures 26 and 28, particularly, the
formulas exhibit an increase, not decrease, in Si content
with increase in Li content, and an approximate 2:1
ratio between the number of positions occupied by Li
and the increase (abovo 2.00) in the number of octahe-
dral sites occupied. The compositional and charge
relations shown in these figures, therefore, indicate
that Li is not accommodated in the structure by simple
occupancy of vacant octahedral sites by Li. In the
actual formula for Stevens’ sample 1 (21, table 6)

—0.20 -0.84

[( Al|.MFe^o|Fe^n i Mgo,c. l Mn^i 1 Lin.7}) (Si a . l> Alo.g4)0|o(OH,F)al~ 1,0< K(Na,Rb,Ce)Loi 01 ,

2.47

the octahedral charge is negative, not positive, Si is
greater than 3.00, not less, and the ratio of positions
occupied by Li to the increase (abovo 2.00) in the
number of octahedral sites occupied is about 5:3, not
1:1. Furthermore, simple occupancy of vacant octa-
hedral sites by Li, with no replacement of Al, cannot
explain the amounts of Li found in many aluminum
lithium micas. The limit of octahedral occupancy

possible, 1.00 octahedral position, is equivalent to
only about 3.75 percent of LijO, whereas many alumi-
num lithium micas contain more than 5 percent of
Li,0.

If the Li content of Steven’s sample 1 is added to
the primary mica above, in the replacement ratio of 1
Li for 1 octahedral Al, the following irrational formula
results:

— 1.61 0.00

[ (Al,.,,Feo^g,Fe^gjMRa.n,Mno + ?jLi 0 , n ) Si 4 0 , 0 (O H ,F),] ~ K ft,*'.
200

The deficiency in positive charges in the octahedral
layer is so great that the negative charge on the layer
is 1.61, and, even with complete filling of the tetrahedral
layer with Si, the charge on the composite layer is
also —1.61, instead of —1.00. Tho greatest amount
of Li that can substitute for octahedral Al, ion for ion,

in an ideal muscovite, and produce a rational formula,
is 0.50:

-i. oo 0.00

[ (Al,, w Li 0 . M ) 8 i 40 io(OH,F ),]- 100 K.tJi 00
' 200

Any greater degree of substitution at this ratio results

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INTERPRETATION OF LITHIUM MICAS

119

in too great a negative octahedral chargo and composite-
layer charge. This Li limit is too low to account for
the composition of many aluminum lithium micas.

A 2:1 Li- (octahedral Al) replacement ratio for the
amount of Li present in Stevens’ samplo 1 in the
primary muscovite above results in a formula,

-0.60

KAI,. w Fe 0 + g 1 Feo + ; > Mjp,.n,Mn 0 + ? a Lio. 7 ,) (8i,, S oAlo.«,)Q,o(OH,F) ? 1- ll>0 K, + io 00 .

2.37

which resembles more closely the characteristics of the
calculated formulas as illustrated in figures 25, 26, and
28; namely, a decrease in Al (IV) content, increase in Si
content, and an increase in total octahedral positions
occupied which is about one-half the number of lithium
positions occupied. The end member for this ratio of
replacement would have the formula,

[ (Al,~^i ; , w ) s”o 10 (OH,F ):]- 100 K,^ 00 .

' rs

In this formula the ratio of positions occupied by Li to
the increase in octahedral positions occupied is 2:1,
the increase in Si is also equivalent to half the increase
in Id, and the decrease in total Al is equivalent to the

increase in Li. These changes can be expressed in the
equation

nLi+n 0.5 Si+0.5 nOct.Site=nAI. (A)

This ratio of replacement permits the admission of
enough Ii into the structure to account for the compo-
sition of the highest amounts of Li that have been
reported in lepidolites. This formula represents the
composition of polylithionite, one of the Li end mem-
bers used by both Stevens and Winchell in their
interpretation of the composition of lepidolites.

Substitution of 3 Li cations for 1 octahedral Al in the
primary muscovite for Stevens’ sample 1 produces a
formula,

[ (Al|.(wFeaoiFe^o a Mgo.o l MnXitLio.n) (8i3.i4Alo. a «)Oio(OH,F) a ) 1,00 K£o6°°,

which is very close to that calculated from the analysis
of this sample, suggesting that the Li- (octahedral Al)
replacement ratio for this sample is very close to 3:1.
The end-member formula for this ratio of replacement,

[ ( Al|. 3oLii.») (Sii.roAI|.oo)0|o(OH,F) a ]~ *•* K£ob°°,

Soo

has the same tetrahedral group as muscovite. As 1.5
cations carrying 1.5 positive charges replace 0.5 cation
of Al, which also carries 1.5 positive charges, there is
no change in layer-charge relations. The composi-
tional changes involved in this ratio of replacement of
Li for octahedral Al may be expressed as

1 ,5nLi + nOct.Sitc «> 0.5n Al <B)

Stevens called this hypothetical end member lithium
muscovite and Winchell called it paucilithionite.
Neither name is satisfactory. Muscovite is a hepta-
phyllic or dioctahedral mica, whereas the above formula
is that of an octaphyllic or trioctahedral mica. Winch-
ell used the prefix pauci because the formula represents
the minimum tenor of Li in a lepidolite end member.
However, the use of this prefix, which means small or
little, for an end member containing more than 5 per-
cent of Li a O, and in which one-half of the available
octahedral sites are occupied by Li, too much mini-
mizes its lithian character. The prefix also exaggerates
the difference between this hypothetical end member

and polylithionite, which contains about 7.5 percent
Li and in which two-thirds of the octahedral sites are
occupied by Li. The tliree Li ions occupying octa-
hedral sites in the unit-cell formula,

O.CO -2.00

[ (AI 3 .ad-i 3 . 00 ) (8i3.ooAl2.oo)Oy)(OU,F)4] *' a> Kj Jo 00 ,

suggests the name “trilithionitc” as more appropriate
for this hypothetical end member. This name also
suggests the 3:1 Li-(octahedral Al) replacement ratio
of this end member.

This discussion of the possible methods of accommo-
dating Li in the muscovite structure shows that simple
occupancy of vacant octahedral sites in muscovite by
Li or replacement of 1 octahedral Al by 1 Li either
produce irrational formulas for end members or pro-
duce end-member formulas whose Li content is too low
to be applicable to the interpretation of the composi-
tion of some lepidolites. Replacement of octahedral
Al by Li in the ratio of 2 or 3 for 1 produces rational
end-member formulas capable of interpreting the
composition of these micas.

RELATION OF LI TO OTHER CONSTITUENTS IN CAL-
CULATED FORMULAS

RELATION BETWEEN LI AND OCTAHEDRAL AL

The relation between the number of octahedral posi-
tions occupied by Li and the number of octahedral

648799— eo — 2

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120

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

positions assumed to have been vacated by A1 in
formulas of analyzed aluminum lithium micas is shown
in figure 25. In a study of the dioctahedral micas
(Foster, 1956) it was found that octahedral occupancy
in these micas is always close to 2.00 and that replace-
ment of A1 by other trivalent and by bivalent cations is
ion for ion. Consequently, in calculating the number
of octahedral-Al positions replaced by Li it was assumed
that 2.00 octahedral sites were occupied in the primary
muscovite, and that replacement of octahedral A1 by
Fe +3 , Fe +1 , Mg, and Mn was ion for ion— such as 1 ion
of Fe 44 for 1 of Al, 1 of Fe +> for 1 of Al. The difference,
then, between 2.00 and the number of octahedral sites
occupied by Al and these other octahedral cations is
assumed to represent the number of octahedral-Al
cations replaced by the Id present. All but a few of
the points fall l>etween line B, which represents the
2:1 Li-(octahedral Al) replacement ratio and leads to
the end member polylithionite, and line C, which
represents the 3:1 Li-(octahedral Al) replacement ratio
and leads to the end member trilithionito.

In the formulas represented by points lying between
these 2 lines, therefore, the Li-(octahedral Al) replace-
ment ratio is between 2 and 3. The location of the
points indicates that in most of the formulas the ratio
is between 2.3 and 2.8. Only 1 of the formulas repre-
sented by points that fall outside the area embraced
between lines B and C contains more than 2.0 percent
Li»0. This formula, in which the Li-(octahedral Al)

replacement ratio is 1.9, is closest in composition to
the end member, polylithionite. The other points that
fall outside the area between lines B and C fall below
line C, indicating that in the formulas that they
represent, the Li-(octahedral Al) replacement ratio is
greater than 3. In most of these formulas, however, the
ratio is quite close to 3, and the discrepancy may l>e
due to slight analytical error, particularly in the deter-
mination of LijO, to lack of homogeneity in the sample,
or to error in assuming that the octahedral occupancy in
the primary muscovite was exactly 2.00 in calculating
the number of Al sites replaced. The amount of
replaced Al in these formulas is so small that an error
in octahedral occupancy in the primary muscovite of as
little as 0.03 less than 2.00 could account for the high
Li-(octahedral Al) ratio in them.

It has been shown that accommodation of Li by
replacement of octahedral Al in the ratio of 2 for 1
involves compositional changes in accordance with
equation A, nLi+0.5nSi+0.5nOct.Site=nAl. In other
words, for each ion of Li or fraction thereof added,
half as many Si ions are added and half as many addi-
tional octahedral sites are occupied, but the loss in
total Al ions (octahedral and tetrahedral) is the same
as the gain in Li ions. 1 1 was also shown that in accom-
modation of Id by replacement of octahedral Al in the
ratio of 3.0 for 1.0 involves compositional changes in
accordance with equation B, 1.5«Li-f «Oct.Site=
O.SnAl. Thus for each 1.5 ion of Li or fractionjthercof

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INTERPRETATION OP LITHIUM MICAS

121

added, two-thirds as many octahedral sites are occupied
and there is a loss in octahedral A1 ions equivalent to
one-third the gain in Li ions. This manner of adjust-
ment involves no change in Si content. As the Ia-
(octahedral Al) replacement ratios in the analyses
studied are, for the most part, between 2 and 3, it would
be expected that they would show compositional changes
between those specified by equations A and B, and that
the closer the replacement ratio in any particular
formula is to 2 or 3, the closer the compositional changes
indicated by that formula will be to equation A or
B, respectively.

-0.41 -0.82

[ (Al|.i9Fe<i.ti?Mno*i,Li|. M ) (3U.MAlf..<

0.17 of the positive charges carried by Li compensate
for the deficiency of the number of positive charges
present in the octahedral layer compared with the
number carried by the same number of trivalent ions.
The effect on the Si content is as though 1.21 and not
1.38 ions of Li were present. In order to eliminate the
effect of the variable amounts of R + * ions present in
the formulas, Si is plotted against (Li— R +I ) in figure
26, not against Li alone. In some of the formulas in
which Li is very low, the positive charges added by
Li do not entirely compensate for the deficiency in
octahedral charge due to the bivalent ions present.

In figure 26 all but a few of the points representing
the (Li— R +, ):Si relation in the formulas fall between

RELATION BETWEEN (LI-R'0 AND MI

The relation between (Li— R +I ) and Si in the alumi-
num lithium micas studied is shown in figure 26. If,
except for Li, the octahedral layer were entirely oc-
cupied by trivalent ions, Li in the formulas would
have been plotted directly against the increase (above
3.0) in Si. However, the octahedral groups in the
formulas are not made up entirely of trivalent ions
plus Li, but also contain varying amounts of bivalent
ions, and some of the positive charges carried by Li
compensate for the deficiency in charge, compared with
Al, of these ions. For example, in the formula for
analysis 34, table 6,

O^OH.FIjI'' ®K(Ns,Rb,C8)?ij 0 ‘.

fine A, which represents the 2:1 — Li: Si relation found
in formulas in which the Li-(octahedral Al) replace-
ment ratio is 2, and line B, the baseline, which represents
the 1.5:0— Li Si relation found in formulas in which
the Li-(octahedral Al) replacement ratio is 3. Thus
the (Li— R +1 ):Si relation in most of the formulas is
consistent with that to be expected in formulas for
aluminum lithium micas in which the Li- (octahedral
Al) replacement ratio is between 2 and 3.

HEI.ATKIN BETWEEN LI AND TOTAL Al.

The relation between the number of octahedral sites
occupied by Li and the total number of formula sites
occupied by Al is shown in figure 27. Except for some

Fwubb 26.— Relation fotween (LI— R**) and SI in aluminum lithium inktu.

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122

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

I'lncue 27. -K«lattoD btlwcen tlw number of formula si lei occupied by IJ nnd R'< In aluminum lithium micas.

points representing formulas with a low content of
Li, almost all the points representing the Li:Al relation
in the calculated formulas of the analyses studied fall
between lines A and B. Line A represents the Li:Al
relation, as compared with muscovite, in formulas in
which the Li-Al replacement ratio is 3.0; line B repre-
sents the Li.Al relation when the Li-Al replacement
ratio is 1.0. The location of most of the points, there-
fore, indicates a decrease in A1 with increase in Li
that is in accordance with the Li:Al relation to be
expected in formulas in which the Li-Al replacement
ratio is between 2 and 3.

RKI.ATION BETWEEN LI AND OCCUPIED OCTAHEDRAL SITES
IN EXCESS OP 2.00

The relation between Li und the number of octahedral
sites occupied in excess of 2.00 is shown in figure 28.
In aluminum lithium micas in which the Li-(octahedral
AJ) replacement ratio is 2, the number of octahedral
positions occupied in excess of 2.00 is theoretically one-
half the number of octahedral positions occupied, as
represented by line B (fig. 28); in aluminum lithium
micas in which the Li-(octahcdral Al) replacement ratio
i9 3, the number of octahedral positions occupied in ex-
cess of 2.00 is theoretically in the ratio of 1.5 Li to 1.0
octahedral position, as represented by line A (fig. 28).
In accordance with the Li-(octahedral Al) replacement

ratios found in the calculated formulas, most of the
points representing the relation between the number
of octahedral sites occupied by Li and the total number
of octahedral sites occupied in excess of 2.00 fall be-
tween the two lines.

RELATION BETWEEN LiiO AND P

A casual inspection of the Li 2 0 and F values in the
analyses in table 6 shows a general increase in F con-
tent with increase in Li a O content. The grouping of
the points in figure 29 along the line representing a
1 : 1 ratio between Li 2 0 and F indicates a tendency to-
ward a 1 : 1 relation in these constituents in aluminum
lithium micas. Considering the difficulties inherent in
the determination of both Li 2 0 and F, some of the dis-
crepancies shown in figure 29 are probably more to be
attributed to error in determination than to other than
a 1 : 1 relation between Li 2 0 and F. Increase in F con-
tent. is accompanied by decrease in H 2 0+ content
(fig. 30).

RELATION BETWEEN LI,0 CONTENT, OCTAHEDRAL
OCCUPANCY, AND STRUCTURE

The variations in composition accompanying increase
in Li content shown in figures 25, 26, 27, and 28 are
those to be expected if Li wore substituted for octahedral

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INTERPRETATION OP LITHIUM MICAS

123

OCTAHEDRAL SITES OCCUPIED BY Li

Flo ore 28.— Relation between 1.1 and octahedral occupant? In circa ot 7.00 In aluminum lithium mltmi.

FtocBK 29.— Relation between LSiO and F In aluminum lithium micas.

A1 in muscovite in ratios varying between 2 and 3 Li for
1 octahedral Al. Compositionally, therefore, these micas
resemble members of an isomorphous series that starts
with muscovite. However, the increase in octahedral
occupancy from 2.00 in muscovite to 3.00 in some
lepidolites and in the theoretical ond members, poly-

Figure 30.— Rclatk-u between P oik) n>0+ to aluminum lithium micas*

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124

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

lithionite and trilithionite, raises the problem of struc-
tural continuity.

Information as to the structure of aluminum lithium
micas is furnished by Hendricks and Jefferson’s study of
Stevens’ lepidolite samples (1939, p. 761), and by
Levinson’s study of aluminum lithium micas (1953)
that varied in Li,0 content from a few tenths of a
percent to more than 7 percent. Included among the
micas studied by Levinsou were most of Stevens’
samples. Except for a few samples in a restricted
range of Li 2 0 contont, both investigators found that the
mica samples studied were not mixtures, as postulated
by Stevens (1938) and Winckell (1942), but that each
consisted of one structural form. Hendricks and
Jefferson found that Stevens’ sample 1 (21, table 6),
which has an Li,0 content of 2.70 percent, has a musco-
vite structure, but that his samples 6-10 and 12-17,
which contain between 5.04 and 7.26 percont LijO, all
have lepidolite structures. Also, samples 2-5 of
Stevens’ suite, which contain between 3.51 and 3.96
percent Li a O and fall, in Li a O contont, between sample
1, with a muscovite structure, and 6, with a lepidolite
structure, were too fine grained for the typo of study
made by them. Levinson (1953, p. 99) speculated that
it seemed likely that “* * * these fine-grained micas
owe their macrostructural defects to small-scale varia-
tions in their crystal structure which itself probably is
assignable to their chemically transitional position in
the muscovite-lepidolite series.” In order to test this
hypothesis, he made detailed powder X-ray studies of
these fine-grained micas and found that they all are
combinations of 2-layer muscovite and 6 -layer lepidolite
forms, with the 6-layer 1 lepidolite form predominating
over the 2-layer muscovite form in all the samples. As
a result of his study of the aluminum lithium micas,
Levinson concluded that micas with less than 3.3 per-
cent Li s O have muscovite structure; those with 3.4 to
4.0 percent Li a O have mixed structures, and that those
with more than 4.0 percent Li 2 () have lepidolite
structure.

Data for correlation of struct lire with the number of
sites occupied by Li atid octahedral cations in Stevens’
samples are given in table 1. These data show that in
the half-cell formula for Stevens’ sample 1, which has
a muscovite structure, octahedral occupancy is 2.47;
in Stevens’ 2, 3, 4, and 5, which are combinations of
muscovite and lepidolite forms, octahedral occupancy
is 2.50 to 2.62 sites; and in Stevens’ other samples, all
of which have lepidolite structures, octahedral occu-
pancy is greater than 2.70. Thus the samples that are
combinations of forms, giving evidence of transition in
structural type, have octahedral occupancies about
halfway between 2.00 and 3.00. In these samples, Li

> Smith uid Yoder (IMA p. 215) renamed this 2Mi.

occupancy is close to one octahedral site. These rela-
tions between Li occupancy, octahedral occupancy, and
structural type in Stevens’ and Berggren’s samples,
which were also included in Levinson’s study, are shown
graphically in figure 31.

Table 1 . — Relation between Lf»0 content, octahedral occupancy ,
and structure of lithium micas analyzed by Stevens

Stevrn* (1 fCftt)

aim

Octal*-
dral oc-
cupancy

Specimen

1.1,0

(percent)

2.70

0.73

2.47

3.51

.94

2.50

3. <0

1.00

2. W

3.81

1.01

2.57

3.V*

1.06

2 .62

6.04

1.3ft

2.72

ft. Oft

1.38

2.M

ft. 1 1

1.3ft

2.73

9..

ft. 33

1.44

2.79

10 ...

ft. 30

1.90

2.93

ft. 51

1.49

2 M

ft M

1.52

2 8ft

ft 78

1.56

•_> 00

ft 8<J

1.61

2. 92

1ft

0.18

1.68

2. 94

0.84

1.84

2.96

7.26

1.03

2 93

Structure

Hendricks and
Jefferson (1US9)

Muscovite

Too fine grained
for study.

6-lsyer monocUnlc.

1 -layer

Not AvnlUblo...-.
6-liyw inonocllnic.

1 -layer

3-layer ttfX&gonal.

1 -layer

.. .do

Levinson (1053)

Normal muscovite.
6-Usrr lepidolite and
2-layer muscovite.
Do.

Do.

I>o.

6-layer monocUnlc
(and lithiiin nu»-
covlte).

Not available.

I -layer .

Not available.

Do.

1 -layer.

3-layer beufonal.

I -layer.

Do.

Just as the transitional samples consist of a combi-
nation of forms, the values reported for various con-
stituents on analysis are composite values made up of
the amounts of these constituents contributed by mus-
covite and lepidolite forms present. For example, the
value for LijO found on analysis in these samples is a
composite value made up of Li a O contributed by the
muscovite present, in which the Li a O content may be
less than 3.0 percent, and of Li a O contributed by the
lepidolite present, in which the Li a O content may be
more than 4.0 percent. Thus the Li a O values in the
area of mixed forms which suggest a continuity in Li
content in figure 31, for example, between nlumini&n
lithium micas of muscovite structure and those of lepid-
olite structure are deceptive, and there is actually a
gap in Li content between these two types of aluminum
lithium micas. Similarly, all the other analytical values
reported for these mixed-form samples are composite
values. Therefore, both the compositional and struc-
tural continuity of the aluminum lithium series is broken
at the point at which change in structure takes place,
and the isomorphous series that starts with muscovite
extends only to an octahedral occupancy of about 2.45
sites and an Li occupancy just short of 1.00 octahedral
site.

Following Schaller (1930), these aluminum lithium
micas having muscovite structures are termed “lith-
ian" muscovites. Levinson applied this term to a
new variation of the muscovite polymorph which he
observed in muscovite containing at least 3.3 percent

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INTERPRETATION OF LITHIUM MICAS

125

Muscovite structure

Mixed forms

3.00

&2.80

~ 2.60
o

</> 2.40

2.20

2.00
0.00

. E

Lepidolite structure

•

e‘°

*13

*12

P *15

e 16

*17

“*9~

EXPLANATION

Stevens* samples (1938)

•

Berggrens samples (1940-41)

Indefinite boundary

0.20 0.40 0.60 0.80 1.00 1.20 1.40

OCTAHEDRAL SITES OCCUPIED BY Li

1.60

1.80

2.00

Fini'xx 31.— Relation brtawn LI occupancy, octahedral occupancy, and structural type In Stevens’ and Rerggrcn’s samples. (Numbers refer to aamplos of Slovens. IMS;

letters refer to samples of Beroncn, I WO, 1WI.)

LijO and possibly as much as 4.3 percent Li a O. In
so doing he applied a chemical term to a structural
variation, whereas Schaller had proposed the use of
the adjectival ending “ian” to names of chemical ele-
ments to describe a variety in which there was minor
and variable replacement of an essential element by
an analogous element, as chromian muscovite, or vana-
dian muscovite. According to this usage a lithian
muscovite is a muscovite containing some Li in place
of Al, not a muscovite having a slight structural vari-
ation over a limited range of LijO content, as used
by Levinson.

Because of their different structure, and the break
in compositional continuity in the transition area, the
lepidolites do not belong to the aluminum lithium iso-
morphous series that starts with muscovite. Ilowover,
in composition they can be interpreted as if they were
a continuation of this series, that is, on the basis of
Li replacement of octahedral Al in muscovite in ratios
varying between 2 and 3 Li for 1 octahedral Al. This
continuation in type and order of replacement beyond
the structural transition zone is illustrated in figures
25 through 31.

Available information on Li content and octahedral
occupancy, Li-(octahedral Al) replacement ratios, and
structure in Stevens’ samples and in Berggren’s sam-
ples that were studied by Levinson, listed in table 2,
shows no consistent correlation between replacement

ratio and structure in lithian muscovites and lepido-
lites. Lithian muscovites have Li- (octahedral Al) re-
placement ratios ranging from 1.5 to 2.9; lepidolites
with 6-layer structures have Li- (octahedral Al) replace-
ment ratios ranging from 2.1 to 2.8, and those with
1 -layer structures have Li-(octahedral Al) replacement
ratios ranging from 1.9 to 2.6. Apparently, therefore,
micas in which the Iji-(oct ahedral Al) replacement ratio
is 2 are not distinct structurally from micas in which
this replacement ratio is 3.

Three polymorphic variations wore found atnong the
lepidolites: the 6-layer monoclinic, the 1 -layer, and the
3-layer hexagonal. Levinson correlated the 6-layer
monoclinic polymorph with lepidolites containing 4.0
to 5.1 percent Li 2 0 (equivalent to about 1.05 to 1.40
octahedral sites in half-coil formulas), and the 1 -layer
polymorph with those having more than 5.1 percent
LijO. However, Hendricks and Jefferson (1939) con-
cluded that there is no apparent correlation between
the different lepidolite polymorphs and composition.
Thus Stevens’ sample 12 (47, table 6), with 5.64 per-
cent LijO, has a 6-layer monoclinic structure whereas
others with lower LijO content (table 1) have 1-layer
lepidolito structures. Nor is there, apparently, any
relation among lepidolites, between octahedral occu-
pancy and the different lepidolite polymorphs. As
shown in table 2, octahedral occupancy in the 6-layer
lepidolites studied ranges between 2.72 and 2.96; that

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126

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

in the 1 -layer lepidolites ranges between 2.73 and 2.96.
Hendricks and Jefferson also found that the 6-layer and
1-layer polymorphs cannot be distinguished optically.

Table 2 . — Comparison of Li occupancy, Li -(octahedral Al)
replacement ratio, and structure

Table*

Sat

MenU*

flcatlon

npfo

(her report*
Author

LtiO
< per-
cent)

ilu*

Octa-

hedral

OCCtl-

policy

Rp*

place*

merit

ratio

Structure

Horftpn‘n, 1!H0. .

a <»

0.18

2.06

1.5

Muscovite.

BcrsRrrn, 1041..

.76

.20

2. 10

2.0

l>o.

BtTRRrvn, 1040. .

1.10

.29

2. 10

2.3

Do.

BerxKren. 1941..

1.1

.30

2.17

2.3

I>o.

1ft

Beracren, two.

1.8

.48

2.31

2.8

Do.

2.45

.66

2.4.1

2.9

Do.

Stcvcnj, ISOS . .

2.70

.73

2l 47

2.8

Do.

5.04

1.35

2. 72

2. 1

(Mayor and

muscovite.

5. or.

1.38

2.84

6- layer.

6.64

1.52

2.85

Do.

Uerncron, .

6.05

1 .50

2.96

2 5

Do.

Stovons ISOS. .

5.11

1.35

2. 73

2 2

Mayor.

3ft

5.33

1.44

2.7ft

2 3

Do.

5.3ft

1.50

293

2.6

Do.

6.78

1.56

2.90

2 4

Do.

6. IS

1.68

2.94

2 3

Do.

6.84

1.84

2.96

2 1

Do.

.....do

7.26

1.63

2.63

1.9

Do.

DISCUSSION

On the basis of chemical evidence alone, the aluminum
lithium micas can be considered os if they were members
of an isomorphous series, starting with muscovite, in
which Li replaces octahedral Al in the ratio of from 2 to
3 Li for 1 octahedral Al. However, structural evidence
indicates that the series is not continuous, cither struc-
turally or compositionally, but is broken about halfway
between muscovite and polylithionite in a zone in which

octahedral occupancy is about 2.50 to 2.60 sites and Li
occupancy is about 0.95 to 1.05 sites. In this zone the
samples are mixed structural forms, muscovite and
lepidolite, whereas samplos with octahedral occupancy
less than 2.50 sites or greater than 2.60 sites are 1
structural form only. As the samples in this zone are
mixtures of forms, the analytical values which suggest
continuity in composition are composite values and do
not actually represent the composition of single-form
aluminum lithium micas having an octahedral occu-
pancy of between 2.50 and 2.60 sites. Consequenth T ,
the compositional continuity is broken. The aluminum
lithium micas, therefore, are members of 2 related
series: the lithian muscovite sorics, which starts with
muscovite and extends to micas having an Li occupancy
of about 0.85 octahedral sites and an octahedral
occupancy of about 2.50 sites, and the lepidolite series,
which starts with a lepidolite having an Li occupancy
of about 1.10 octahedral sites and an octahedral occu-
pancy of about 2.65 sites and extends to a lepidolite
having an Li occupancy of from 1.80 or more octahedral
sites and an octahedral occupancy of about 3.00 sites.
Selected formulas are given in table 3 that show the
relation of lithian muscovites and lepidolites. This
relation is shown graphically by histograms in figure 32.

The chemical composition of both the lithian mus-
covites and lepidolites can be interpreted in the same
way; that is, as if they were derived from muscovite
by the replacement of octahedral aluminum by lithium
in a ratio varj'ing between 2 and 3 Li for 1 octahedral.
The other compositional changes that characterize

Table 3. — Selected formulas illustrating relation bettceen lithian muscovites and lepidolites

Ll-toctalud’at At)

Number In table S ^ ^ ^ formula replacement ratio

Lithian muscovites.... 2 [ (AI|.wFc^Fc t i'taLio.o > ) (Sit.(ioAl l .oo)O l o(OH) 2 j '•°*(K,Na,Ca/2) + l;o 3 2.0

' iai ’

16 l (Ai|,7|Fc^^Fe l ')'iMMgi.o;MnaoiLio.37) (8i3.i3Aio.8;)Oio(OH)2) t ' M (K,Na,Rb,Cs,Ca/2)'*'!;ot 2.3

2.17

-0.20 -0.M

21 [ (Al,.MFco^,Fp n 4 n |Mg,,n,Mno^? t Lin.n) (3i,,ioAlo. g ,)0,o(On)2l- tlM (K,Na,Rb,Cs) + l;g} 2.8

2.47

Mixed

structural

forms

Lepidolitee ... ...34 [(Ali.joFeo'niMno'loLii.asXSis.ssAio.ulOiofOHL] I ' C9 (K,Na,Rb,Cs) + i;o3----- -

2.84

62 [(Al,.3r.Fco."o?M(t'’.r'iMno.'olLi|,g|)(Si3.<8Alo.M)Oio(011)i] 1 w (KiNa,Rb,Cs) + J;«

67 [ ( Al,, n}F<^oi Mg i.p}M noffi.il. a<) (Sis. mAIo. i?)Oh,(0 H ) j) , ’ M (K,Na,Rb,Cs) + I*S«

’ i!55

2.6

2.3

. 2.1

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INTERPRETATION OP LITHIUM MICAS

127

Lithian muscovites

Mixed forms

Lepidolites

4.00

EXPLANATION

■ a E3 a a

U Octalicd- Si Octahedral Indefinite
rat A1 ^occupancy boundary"

SAMPLE

: (Fto cbb S3. — Ulstujcrams of setoetad formutaa showing '.be relation of Utblon muscovites and lepidolites. (Numbers below hlstogmms refer to analytes In table 7.)

these micas — increase in silica and decrease in the
tetrahedral A1 with increase in Li content — are neces-
sitated by the disparity in positive charges carried by
the replacing Li and replaced octahedral Al.

The interpretation of the composition of these micas
postulated by Stevens (1938) and Winchell (1942), as
mixtures of end members, is not borne out by the struc-
tural work of Hendricks and Jefferson (1939) and
Levinson (1953).

The relation between Li, R + *(F e +I ,Mn +1 , Mg) , and
octahedral R +s (Al,Fe + *)-fTi' M is shown in figure 33, in
which the percentages of occupied octahedral sites
occupied bj’ Li, R +5 (Fe +l ,Mn + *,Mg), and octahedral
R +3 (Al,Fe +J )-f Ti +4 in each formula are plotted on a
triangular diagram. In this diagram ideal muscovite
falls at the lower left corner, which represents 100-per-
cent occupancy of the octahedral layer by Al(-f Fe**),
triiithionite is represented by a point midway along the
left aide of the triangle, and polylithiouite is represented
by a point two-thirds of the way up tho left side of the
triangle. The points representing octahedral occu-
pancy of the calculated formulas of lithian muscovites
and lepidolites are distributed along the left side of the
triangle from the lower left corner, which represents
muscovite, to the point representing polylithionite.
Because of the small amounts of FeO, MnO, and (or)
MgO found in most lepidolites, few of these points fall
on the outside bouudary, as do triiithionite and poly-
lithionite. However, all fall between the outside bound-
ary and the line representing 10 percent of bivalent
octahedral cations, Fe +3 , Mn +1 , and Mg.

FERROUS LITHIUM MICAS

PREVIOUS INTERPRETATIONS OF COMPOSITION

Both Kunitz (1924, p. 409) and Winchell (1927, p.
274) regarded lepidolite and protolithionite as end mem-
bers of a series characterized by decrease in Li content
and increase in Fe +1 , with protolithionite representing
the Fe +, -high, Li-free end of the series. Intermediate
members were known as ziimwaldites. Kunitz believed
that lepidolite, KHjAl*Le(SiO«),, contained a special
group (2Li,Si), denoted as Le, that was completely
replaceable by 3Fe + * to form protolithionite. Winchell
considered that lepidolite was miscible in all proportions
with protolithionite in tho crystal state, and that the
natural lepidolites, zinnwaldites, and protolitbionites
were made up of various proportions of tho end mem-
bers. He regarded cryophyllite, a lithium mica de-
scribed by Cooke (1867) from Cape Ann, Mass., as
doubtful. At that time Winchell considered these
minerals heptaphyllites, but later (1942, p. 117) he
recognized them as octaphyllites and, furthermore,
included some lithium in his formula for protolithionite.

Hallimond (1925, p. 311) also believed that lepidolite,
zinnwaldite, and protolithionite form a series. How-
ever, as indicated by his formulas, R 2 0-Lij0-2Al 2 0f
6Si0 5 -2H 3 0, for lepidolite, and KjOLijO-3RO-2AljOr
6Si0 3 2HjO, for protolithionite, this series is
characterized merely by addition of RO, the LijO
content remaining constant. Thus Hallimond’s series
was not a replacement series. The two zinnwaldites
reported by Dana, he states, might be regarded as

M678S— «0 8

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128

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

consisting chiefly of the compound KjO-LijO-RO-
2Alj0j-6Si0 a -2H 2 0 or, alternately, as mixtures of
lepidolito and protolithionite. He believed that cry-
ophyllite bears the same relation to lepidolite that
phengite bears to muscovite.

A classification by Ginzburg and Bcrkhin (1953) in-
cludes the ferrous lithium micas as part of a series of
which lepidolite is the high-Li end member and biotite
is the Li-free end member. In this series the transition
from biotite to lepidolite is supposed to be marked by
the replacement of 2Mg +J by Li and Al +3 .

Thus four kinds of series have been proposed to inter-
pret the composition and relation of the ferrous lithium
micas: the lepidolitc-protolithionite series of Kunitz
(1924, p. 409), in which the Le group (2Li,Si) is com-
pletely replaced by 3Fe +I ; the lepidolitc-protolithionite
series of Winchell, in which the end members are mis-

cible in all proportions and form intermediate members;
the lcpidolite-protolithionite series of Hallimond, in
which Fe +J is additive but Li remains constant; and
the biotite-lepidolite series of Ginzburg and Berkhin,
in which 2Mg is replaced by (Li+ Al). In none of these
series are the limits in composition between lepidolite,
cryophyllite, zinnwaldite, and protolithionite defined.

The clearest definition of the limits of composition
between protolithionite, zinnwaldite, and cryophyllite
is that stated in Hey (1955. P- 208). Hey gives the
same formula 2(K 2 (Li,Fe +J ,Al)s(Si,AJ) fi O so (F,OH)J for
all three, excepting only that Fe +3 is included in the
(Li,Fe +3 ,Al) group in his formulas for protolithionite
and cryophyllite, but he qualifies the formulas by ob-
servations on the amounts of Li, Fe +3 , and Si typically
present. Thus in protolithionite, zinnwaldite, and
cryophyllite, Li occupies 1-2, »2, and «2# formula

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INTERPRETATION OP LITHIUM MICAS

129

positions, respectively; Fe occupies *» IK, « 1M, and
« 1 (including Fe +1 ) formula positions, respectively;
and Si 5K~6, «6M, and *»7 formula positions, respec-
tively. Following Dana (1892, p. 626), Hey gives zinn-
waldite species status, with protolithionite and cryo-
phyllite being considered varieties of zinnwaldite.

COMPOSITIONAL CHANGES SHOWN BY ANALYSES

The analyses of ferrous lithium micas vary consider-
ably in SiOj and AljOj content, although there is a
general increase in SiOj content and decrease in AljO,
content with increase in LijO content. However, these
relations are not as consistent as in the aluminum
lithium micas. The Fe a Oj content is quite variable in
ferrous lithium micas having less than 3.5 percent of
LijO; in ferrous lithium micas having more than 3.5
percent of LijO, FejOj is generally low or absent.
FeO is also quite variable, but, in general, decreases
with increase in LijO content. All but 1 of the ferrous
lithium micas included in the study that contained less
than 2 percent of LijO have more than 15 percent of
FeO, those with between 2.0 and 3.0 percent of Li s O
have between 9.0 and 14.0 percent of FeO, and those

A. Siderophyllites and

Number
into bit 7

-0.08

1 — [(A.lo.OTTio.oiFcixoaFei*. a»Mgo.o a Mn^^ )(8i

3.44

+0.35

2 [(Alo.73Feo.'osFei t .| 8 Mgo.o|Mnt^p;Li<i 1 o )(Si 2

Xtt

+0.34

4 KAlo.itTio.cgreitiaFp^faMgo o»Mn<tosLio.ii) ('

384

B. Ferrous lithium mi
+0.08

9 [(i.o»'rio.n3Fei + f 3 Mg i ).oiMn^’ ) Lio. <2 ) (Si2.7i

with more than 3 percent of LijO have between 6.0 and
12.6 percent of FeO. MgO is generally low. Many
of the analyses contain less than 0.5 percent, and few
contain more than 1.0 percent. Only 1 analysis has a
significant amount, 5.23 percent.

In most of the formulas calculated from the analyses
the number of octahedral sites occupied is greater than
2.60. These micas are, therefore, trioctahedral or
octaphyllic micas, not heptaphyllic micas as was
formerly assumed by Winchcll (1927, p. 274).

RELATION BETWEEN FERROUS LITHIUM MICAS,
SIDEROPHYLLITE8, AND ALUMINIAN LEPIDOM BL-
ANKS

In their principal compositional characteristics,
their low MgO content with high FeO content, their
octahedral occupancy, and their octahedral-tetrahedral
charge relations, the ferrous lithium micas with low
LijO content resemble siderophyllites and Iepidomel-
anes, which are the low-Mg members of the phlogopite-
biotite-sidcrophyllito (or lepidomelane) Mg replacement
system (Foster, 1960, p. 30). The similarity in compo-
sition is illustrated by the following formulas:

aluminian lepidomelanee

«A”» 6 )O,„(OII,F)jl- 100 K(Na ( Ca/2) 0 + ^*»

3i a .«a".i.)O i o(OH,F) 1 ]- # - ”K(Na,Ca;2)£
cas (LijO <C.1.& percent)

Ah.*4)0,o(OH,F)jl- , "K(Na,Ca/2)fJ i , »

,..[ (Aln.7iFe^!3Fcj l 'j«Mgr l ,raMn<xf()LI(i,<5) (Bij.jiAI|.o7)Oio(OH,F)j] , '®®K(Na,Ca/2)^Jj 0 *

3.78

[ (Alc ^Tin C qFe,) f ;iiFe|*| < Mgfl i n2Mn l *[ijLi,i <7 ) (Sij. 8 jAl|.u)Oio(OH,F)j] °’ w K(Na,Ca/2)o.

396

In both these groups Mg is insignificant and Fe + * is the
dominant octahedral cation, but the amount of Fe +J
present varies greatly. In some siderophyllites and in
somo of the ferrous lithium micas, A1 is the principal
trivalent octahedral cation, in others in both groups
there are significant amounts of trivalent iron. Indeed
some low-Mg, high-Fe +I trioctahedral micas, lepidome-
lanes, contain trivalent iron as the greatly dominant
octahedral cation. In formulas calculated from analy-

ses of ferrous lithium micas, the dominant trivalent
octahedral cation is usually Al, some contain consider-
able Fe +S , but Fe +3 is not greatly dominant in any of
the calculated formulas studied. In tho study of the
phlogopite-biotite-siderophyllite (or lepidomelane) sys-
tem (Foster, 1960), it was found that replacements of
Mg by bivalent iron (Fc + *), and by the trivalent ions,
Al and Fe + *, proceed quite independently; a given
degree of replacement by Fe +J has no relation to the

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130

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

degree of replacement by A1 or Fe +1 , nor has the degree
of replacement by A1 any relation to the degree of
replacement by Fe + *.

The octahedral charge in the siderophyllites and the
ferrous lithium micas is usually positive, but it may be
about neutral or even slightly negative, depending on
how the additional positive charges carried by trivalent
octahedral cations (as compared with the number of
charges carried by bivalent cations) have been accom-
modated in the structure (Foster, 1960, p. 16), and the
negative tetrahedral charge may be considerably greater
than 1.00, close to 1.00, or less than 1.00, depending on
the octahedral charge. Octahedral occupancy also
varies considerably, depending also on how the addi-
tional positive charges of trivalent octahedral cations
have been accommodated.

The similarity in characteristics of siderophyllites
and ferrous lithium micas suggests that the sidero-
phyllites are the prototypes from which the ferrous
lithium micas are derived. It should be noted here
that most analyses of siderophyllites and lepidomelanes
include small amounts of Li a O. Some materials that
have been called siderophyllite contain as much as 1
percent of Li a O.

COMPOSITIONAL RELATIONS IN SIDEROPHYLLITES
AND FERROUS LITHIUM MICAS

URINATION BETWEEN LI AND TRIVALENT OCTAHEDRAL
CATIONS

The relation between the number of formula sites
occupied by Li and by trivalent octahedral cations (A1
and Fo +s ) in siderophyllites and ferrous lithium micas
is shown in figure 34. The number of octahedral sites
occupied by trivalent cations is more variable, and in
general lower, in the sidorophyllites and aluminian
lepidomelanes and in the ferrous lithium micas having
less than 1.5 percent of Li a O (about 0.5 octahedral
sites), than in ferrous lithium micas containing more
than 1.5 percent Li a O. In the latter the octahedral
trivalent cationic content is remarkably constant over

“ £ 100
o>3

— J »-
< Z
S3

xg 0 80

0 60

•

• •

•

• •

. ?*

# l
• • •

•

n 0

•

EXPLANATION

StderopftyM**

•

Far rout lithium mica?

0 00 0.20 0 40 0 60 0 80 1 00 1.20 1.40

OCTAHEDRAL SITES OCCUPIED BY U

Fjourk 3'..— Eolation between Liquid octahedral R* cations In siderophyllites nnd
fcrrou.i lithium miens.

a range in Li a O content of from 1.5 to 4.8 percent.
This relative constancy in octahedral trivalent cationic
content suggests that these cations are not involved
in the addition of Li to the structure.

RELATION BETWEEN U AND FE 1 '

The relation between Li and Fe +J in siderophyllites
and ferrous lithium micas is shown in figure 35, in

200
1.80

1.60

140

>•

g 120

* 1.00

i 080

060

040

020

0.00 0 20 0 40 0 60 0 80 1 00 1 20 1.40

CCTAHCDRAl SITES OCCUPIED BY U

Fiocre 35.— Rr Lilian between LI and Fc*» In sJdcrophyllltca and ferrous lithium

miens.

which the number of octahedral sites occupied by
Fe + * is plotted against the number of sites occupied by
Li. The Fe + * content of siderophyllites (including
ferrian siderophyllites and aluminian lepidomelanes)
varies greatly, as does also that of the ferrous lithium
micas. Even those containing about the same amount
of Li vary greatly in Fe + * content. In general, how-
ever, there is a sharp downward trend of the points
with increase in Li content, which is suggestive of re-
placement. The ratio of replacement is, however,
difficult to determine because of the great variation in
Fe +J content in ferrous lithium micas having low Li
content, as well as in the siderophyllites from which they
are hypothetically assumed to have been derived, as
indicated by the great variation in Fe +J content in the
siderophyllites at hand. Thus there is no definite point
of departure with respect to Fc +1 content from which to
calculate Fo +J replacement as there was with respect to
A1 content and AI replacement in the lepidolites.

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INTERPRETATION OF L I T HIUM MICAS

131

RELATION BETWEEN U AND 81

The relation between Li and Si in siderophyllites
(including aluminian lepidomelanes) and ferrous lithium
micas is shown in figure 36, in which the number of

OCTAHEOSAl SITES OCCUPIED BY U

Finest 34.— Relation between LI and 81 In siderophyllites and (croons lithium

micas.

formula sites occupied by Si is plotted against the num-
ber of formula sites occupied by Li. As in Fe +J content,
the Si content varies greatly, even in micas having about
the same Li content. This difference in Si content in
samples having about the same Li content is due to the
manner in which the additional charges carried by
trivalent octahedral cations are accommodated in the
structure (Foster, 1960, p. 16). If the additional
positive charges are accommodated predominantly as
a positive charge on the octahedral layer and neutralized
by a negative tetrahedral charge which is greater than
1.00 by an amount about equivalent to the positive octa-
hedral charge, the Si is considerably lower than if the
additional positive charges are predominantly neutra-
lized by anions associated with unoccupied octahedral
sites. This variation in Si content, owing to differences
in the way in which the additional positive charges
were accommodated, in ferrous lithium micas with about
the same Li content is illustrated in the formulas for
analyses 22 and 23, table 7, that follow:

[(Alo.toTio.oaPe^^Fe^liMgo.toLio.^t) (Si 2 Alj .») O jo(OH, F) j] “ 1 0! K (Na,Ca/2)^ Jj 0 * *

( (Al 1 .,oTio.o 7 Peot? l Mg 0 , M Mn 0 ^Lio. w )(8i 3 joAl <) , a) )0 1> (OH,F) 3 r <)ll8 K(Na,Ca/2)o^ w
' zn ’

The LijO content in the micas represented by these
formulas is almost the same, 3.39 and 3.40, respectively.
But the SiO ! content of analysis 22 is only 39.04 percent,
as compared with 46.37 percent in 23. In 22, octahedral
occupancy is complete. Univalent Li compensates for
0.98 of the additional 1.19 positive charges carried by
Al, Fe + ’, and Ti +1 ; the remainder form a positive charge
(+0.19) on the octahedral layer that is neutralized by
an equivalent increase, above 1.00, in the negative
tetrahedral charge. In 23, only 2.76 octahedral sites
arc occupied. Univalent Li compensates for 0.94 of
the 1.24 additional positive charges carried by Al and
Ti ; the rest are neutralized by negative charges associ-
ated with unoccupied octahedral sites. However, the
0.24 unoccupied sites make 0.48 such negative charges
available, and as only 0.30 are need to neutralize the
uncompensated additional positive charges, the octa-
hedral layer is left with a negative charge of —0.18.
In order that the unit layer charge be close to — 1 .00,
the negative tetrahedral chargo must be less than 1.00

by the same amount. Because, therefore, of the dif-
ferent ways in which the additional positive charges
carried by trivalent cations are accommodated in the
structure in such trioctahedral micas as the ferrous
lithium micas, there is considerable variation in Si
content, even in those in which the Li 2 0 content is the
same. However, despite such differences in Si0 2 con-
tent, the upward trend of the points in figure 36 suggests
that increase in Li content is accompanied by increase
in Si content, although the angle of trend of increase is
less than the angle of trend of decrease in Fe +J content.

HYPOTHETICAL FE«-LI REPLACEMENT RATIOS

If Li replaces Fc + * in the ratio of 2:1, the number of
positive charges carried by octahedral cations is not
changed, and, consequently, the octahedral and tetra-
hedral charges and Si are unchanged, but the octa-
hedral occupancy is increased by one-half the number of
Li cations added. This is illustrated in the following
formulas, in which 1.00 Li is substituted for 0.50 Fc +!
in the formula for analysis 4, table 7.

+0.24 -1.19

[ (Alo. 44 TioAeFe^ 4 g Fe^|jMgo.ft 3 Mp{f liflLiojg) (Si 2 .giAli.i()Oio(OH,F)j] 0 ‘* 5 K(Na,Cn/2)£%j M ,

2.64

[ (Al 0 .44Tio. w Fe 0 *?,Fe^M fo . 0> Mn 0 + ^Li,.u) (Si 2 .^Al 1 ,, > )0,o(On,F) 2 ]- 0 -* s K(N a ,Ca/2)o 4 .i 2 9e .

3.14

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132

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The octahedral-tetrahedral charge relation and the Si
are the same in the second formula as in the first, but
octahedral occupancy is increased by 0.5 and is greater

[ fAlo^Tioo^Pe^jjPe^hMgo.oiMno.otLii.tt ) (
2.M

the octahedral occupancy remains the same, but the
layer-charge relation is greatly altered, and there is an
increase in Si equivalent to the increase in Li and the
decrease in Fe +J . The increase in Si, equivalent to the
increase in Li and to the decrease in Fe +1 , is greater than
indicated by the comparative angles of trend of the
points in figures 35 and 36, which indicate that the
general increase in Si is generally less than the decrease
in Fo +1 . The negative octahedral charge is considerably
greater, and the negative tetrahedral charge is con-
siderably less, than in any of the calculated formulas of
ferrous lithium micas.

( ( Alp uTip.roFect IsMgp .o»M n o. opLii ,u) (
' __ '

In this formula, the increase in Si (+0.5) is equivalent
to one-half the increase in Li content (+1.0) and to
two-thirds the decrease in Fe + * content (0.75). This
relation between Li and Si is about that suggested by
the trend of the points in figure 36, and the relation
between Si increase and Fe +! decrease is comparable
to the relative trend of points in figures 35 and 36.
The octahedral-tetrahedral charge relation in this for-
mula and the octahedral occupancy are also comparable
with those found in the calculated formula for ferrous
lithium micas (the data for writing these calculated
formulas are included in table 7). The replacement
ratio probably varies considerably, possibly as much
as from 2:1 to 1:1 Li for Fe +a in certain specimens of
ferrous lithium micas, but a replacement ratio of about
2:1.5 Li for Fe + * best explains in general the amount
of decrease in Fe + *, the amount of increase in Si, the
octahedral occupancy, and the octahedral-tetrahedral
charge relations found in calculated formulas of ferrous
lithium micas.

The changes in composition that take place in re-
placement of Fe +I by Li in this ratio can be expressed
briefly as 4nLi + 2nSi = 3nFe +, + 2n. tetrahedral Al.
Octahedral trivalent cations, Al and Fc +S , are not in-
volved in the replacement, as is indicated in figure 34.

SIDEROPHYLLXTE-LEPIDOLITE ISOMORPHOU8
SERIES

The relation between Li, R + *(Fe + *,Mn + *,Mg), and
octahedral R +3 (Al,Fe +3 )+Ti +4 in siderophyllites and
aluminian lepidomelanes and ferrous lithium micas is

than 3.00.

If, on the other hand, Li replaces Fe +J ion for ion in
the formula for 4, above,

l». 8 iA4.i.)0 1 o(OH,F),)- ##! K(Na 1 Ca/2) 0 + Sj w ,

Neither of these types of replacement of Fe + * by
Li, therefore, correlates well with the characteristics
of the ferrous lithium formulas nor with the degree of
Si-increase, Fe +J -decrease relation suggested in figures
35 and 36. Substitution of Li for Fe +l in the 2:1 ratio
results in no change in Si content; substitution of Li
for Fe +1 in the 1 : 1 ratio results in a greater increase in
Si than indicated by figure 36. This suggests that
the replacement ratio lies between 2:1 and 1:1. In
the formula below, a replacement ratio of 2:1.5 (1 Li
for 0.75 Fe +J ) in the formula for analysis 4, table 7, is
assumed.

i»^°Alo. M )0 1 o(OH,F) J ]- OM K(Na 1 Ca/2)J^.

shown in figure 37, in which the percentages of occupied
octahedral sites occupied by Li, R +, (Fe + *,Mn + *,Mg),
and octahedral R + *(Al,Fe +3 )+Ti +4 in each of the cal-
culated formulas used in this study are plotted on a
triangular diagram. The points representing sidero-
phyllites and aluminian lepidomelanes occupy an area
at the base of the triangle just to the right of the center.
Only one point, representing a siderophyllite in which
no LijO was reported, falls on the baseline. The other
five points, which represent siderophyllites and lepido-
melanes which contain small amounts of LiiO, fall a
little above the baseline. The points representing the
the ferrous lithium micas fall in a band trending diago-
nally upward from the area occupied by siderophyl-
lites and aluminian lepidomelanes toward the point
representing polylithionite. Calculated formulas rep-
resenting progressive stages of replacement of ferrous
iron by Al in the siderophyllite-lopidolite isomorphous
series are given in table 4 and are represented graph-
ically in histograms in figure 38. Both the formulas and
histograms illustrate the progressive changes in compo-
sition that take place with increase in Li content,
particularly decrease in Fe +! content and increase in
Si content.

The slight hiatus between points (fig. 37)representing
siderophyllites and aluminian lepidomelanes and those
representing ferrous lithium micas serves to differen-
tiate the former and protolithionitc, but differentiation
between protolithionites and zinnwaldites must be on
an arbitrary basis, as there is no hiatus between points
representing these varieties.

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INTERPRETATION OF LITHIUM MICAS

133

R+ 3 (Al, Fe ,3 )+Ti** R* J (Fe w . Mn* } . Mg)

Ytovzz 37.— Rota! Ion between LI, R»>(Fe* , .Mn‘ , .M*) 1 anil octahedral R^KALPe^H-Tl* In sMcrophyUltce and Icmnia lithium mica*.

Tabus 4. — Selected formulae representing steps in the eider ophyllite-lepidolite series
Number In U t O

table 1 Formula (percent)

3 [ (AI 0 .«Ti < ,.o,Fe^|,F^Mgo. <> ,MD 0 tg a Lio,i t ) (Sfe.'j.X .„)O 10 (OH,F),)- , OT K(Na,Ca/2) 0 + ii <>s 0.39

' ISi

9 [(Al K oaTto, M Fc,tf,Mfo,o,Mn 0 ^Lio,« a ) (Si,.7, 1 Al 1J «)0,,(OH,F) t ]- | lg K(Na,Ca/2),tJi u 1.44

2.08

15 [ (Al 1 . at Fe^^l 7 Mgo.o e Li«.,,) (Si i ^Alo, M )0,o(OH,F) > ]- , w K(Na)ito»°® 2.42

' 173

18 [ (AI, wFeo^F^UMno^oLio.g,) (Sia.MAlo.^OtoCOH.F),]- 0 ** K(Na) 0 + g,» 4 3.28

2.83

31 [ (Ali, ll Fe^iiFe^ > Mn c H :? t Li|.i g ) (Si,~ M 0 AU. M )Oi,(On,F) 1 )- | M K(Na) l + ij w 4.18

333

35 [ (Al 0 , w Fe 0 + J,FeSMno, 03 Li,, a ) (Si } I 8 A? 0 , <3 )0, 0 (OH,F) a ]-° w KtNa)^ 00 4.99

53 * ’

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134

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Lepidolite

(fcrrojn)

Siderophyllrte Prololithiomles Zinnwsldites Cryophyllite

SAMPLE

Figure iS.-Htaoprams of selected formulas rvprescmlsg steps In tbe stderophyUllea-kpldoliM series. (Numbers below histograms refer to analyses In table 7.)

SIDEROPHYLLITES AND t.KPTTtftM EI.AV Ffi

Siderophyllites and Iepidomelancs are the high-Fe 44 ,
low-Mg members of the trioctahedral Mg replacement
system of which phlogopitc, Mg 3 . 0 (Sij.»Al,.o)Oio(OH,
F)jK,. e , is the high-Mg, low-Fe 44 member (Foster,
1960, p. 24). Heretofore it has been assumed that the
high-Fe +J end member of a Mg-Fe 44 replacement scries
is annitc, Fei'S(Si 4 j > Ali.o)Oio(OH, F) a Ki. 0 , the Fe 44
analog of phlogopitc, but a study of analyses of natural
trioctahedral micas showed that no natural representa-
tive of such a mica has been recorded in the literature,
that replacement of Mg by Fe 44 is also always accom-
panied by more or less replacement by Al and Fe 44 ,
and, consequently, that the low-Mg, high-Fe 44 end of
the system is represented not by annite but by sider-
ophyllite, in which the principal octahedral trivalent
cation is dominantly Al, and lepidomelane, in which
it is Fe 44 . High-Fe 44 , low-Mg trioctahedral micas
that contain both octahedral Al and Fe 44 are termed
ferrian siderophyllites, or aluminian lepidomolnnes,
depending on whether octahedral Al or Fe 44 is dominant.

+0.35

[ (•^lo.*>F < \togF<- > i*'| 3 MB3.oiMnjirnLio.|o) (Si a .

2.82

In some formulas the amounts of octahedral Al and of
Fe 44 present are about equal.

In most of the formulas calculated from analyses of
ferrous lithium micas, Al is the predominent trivalent
octahedral cation, although in a few formulas Fe 44
is equal to, or slightly greater than, the octahedral Al.
However, in none is Fe* greatly dominant over tri-
octahedral Al. This suggests that the siderophyllites,
ferrian siderophyllites, and aluminian lepidomclanes
are prototypes of these minerals, but not lepidomelanes,
in which Fe 44 is greatly predominant.

The available calculated formulas of these prototypes
vary considerably in content of Fe 44 , Fe 44 , and octa-
hedral Al. In the analyses at hand, Fe 44 ranges from
1.22 to 1.88 occupied sites and averages 1.50, Fe 44
ranges from 0.05 to 0.62 and averages 0.36, and octa-
hedral Al ranges from 0.44 to 0.99 and averages 0.57.
Total trivalent octahedral cations (R 44 ) range from
0.81 to 1.14 occupied octahedral sites and average 0.93.
The reciprocal extremes in It 44 and Fe 44 content are
illustrated in the following formulas for analyses 2 and
3, table 7,

!S. S 5)0,o(OH,F) } ]- ,w K(Na,Ca/2)„tSj M ,

[ (Ati.aTio.oiFe 0 ' 4 'a a Fei + i a Mgo(flMno~o 1 Lio,i3) (SI;.agAl|.3;)0|o(OH,F) a ]~ l ' cl,7 K(Na,Ca/2) l £aj 06 .

zoi

The first formula, calculated from analysis 2, table 7,
has the highest Fe 43 content and the lowest octahcdral-
R 44 content of the available analysis of siderophyllites
and aluminian lepidomelanes; the second formula, cal-
culated from analysis 3, table 7, has the lowest Fe 4 *

and the highest octahedral R 44 . Thus siderophyllite,
the prototype of the ferrous lithium micas, varies
greatly in Fe 44 , Fe 44 , and Al content, just as ferrous
lithium micas that contain about equal amounts of Li
may vary widely in these constituents.

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INTERPRETATION OF LITHIUM MICAS

135

In all but one of the analyses of sideropliylllte the
presence of a small amount of Li is reported.

PBOTOUTHIONITB8

Kunitz (1924, p. 409) considered protolithionite the
lithium-free member of a ferrous lithium mica series of
which lcpidolite was the high-Li end member, with a
formula, KH 5 AlFe^ J Si,Ou, that is identical with Win-
chell's formula for annite. At this time Winchell (1927,
p. 274) also considered protolithionite Li free, but
heptaphyllic (or dioctahcdral), with the formula
H 4 K 2 Fe^ 3 Al 4 Si 6 0 J2 . Later Winchell (1942, p. 117)
recognized it as octaphyllic (or trioctahcdral) and used
is as an end member, representing the maximum tenor
of bivalent cations together with a minimum tenor of
Li, in interpreting the composition of lepidolitcs. In
the formula which he then assigned to protolithionite,
K a Li Fet 3 AljSiaOjoF 4 , Li occupies 1 unit-cell formula
site. Hey (1955, p. 208) observes that Li occupies be-
tween 1 and 2 sites in the unit-cell formula.

Perhaps because of these considerable differences in
the Li content in published formulas for protolithionite,
published analyses for materials called protolithionite
also vary considerably in Li content. JNo analj’ses
purported to be those of protolithionite were dis-
covered in which no Li 2 0 was reported, but one pub-
lished as that of a protolithionite contained only 0.32
percent of Li 2 0 (00.10 octahedral site in the half-cell
formula), and another contained only 0.39 percent of
LijO. On the other hand, another analysis reporting
4.57 percent of LijO (01.30 octahedral sites in the
half-cell formula) was also called that of a protolithio-
nitc. The literature indicates, therefore, a slate of con-
siderable confusion as to the I,i 2 0 content of proto-
lithionite.

In the present study the Li content of protolithionite
is defined as 0.5 ±0.25 octahedral sites in the half-cell
formula, or 1.00 ±0.50 sites in the unit-cell formula.
This Li content is based on the Li content in the
formula used by Winchell in 1942 and on Hey’s state-
ment as to the Li content of protolithionite. A range
is given for Li becauso these micas are interpreted as
belonging to an isomorphous series, the members of
which contain varying amounts of Li. This is the range
bracketed opposite protolithionite in figurc37. Thcpcr-
missible site occupancy given is equivalent to a range of
from about 0.75 to about 2.50 percent in Li 2 0 content.
Ferrous lithium micas containing a little Li 2 0 but less
than 0.75 percent, like those represented by points near
the baseline in figure 37, are considered iithian sidcro-
phyllites, or lepidomclanes, depending on the A1 and
Fe +3 content. Those containing more than 2.50 per-
cent of Li 2 0 are considered zinnwaldites or ferroan
lepidolitcs.

In the protolithionite analyses 7-15, table 7, Li varies
from 1.19 to 2.42 percent Li 2 0, equivalent to a varia-
tion in octahedral sites of from 0.37 to 0.71 in the half-
cell formula. FeO, as in the siderophyllites, is quite
variable, ranging from 10.20 to 21.97 percent (0.61 to
1.44 octahedral sites in the half-cell formula). The
octahedral content of trivalent cations, A1 and Fe +3 ,
with Al usually dominant, is considerably more con-
stant, varying only between 0.91 and 1.21 octahedral
sites. These ranges in content of the principal octa-
hedral cations can be expressed as follows:

(R t ^ 104 : 0 . Mifeit oo Aa <OiLio. w±o.2s) .

Winchell assumes full octahedral occupancy in the
formula for protolithionite that he used in 1942 in his
interpretation of the composition of lepidolites. In
this formula, recast in the half-cell notation used herein,

0.00 - 1.00

[ (Alo,tFe^jLio. c ) (3i 2 .oAli.o)Oio(OH) 2 )- | ' oa K^qq 00 ,

3X0

the excess in positive charges carried by Al (as com-
pared with the number of positive charges carried by
bivalent cations) is exactly compensated by the defi-
ciency in positive charges carried by Li, and the octa-
hedral layer is neutral. All the charge on the unit
composite layer is on the tetrahedral layers owing to
the substitution of Al for one Si cation. However, in
all the formulas calculated from analyses of natural
protolithionites, the octahedral trivalent cations, Al
and Fc +S , with usually a little Ti, are considerably in
excess of Li, so that there are extra positive octahedral
charges to be accommodated in the structure. In most
of the calculated formulas the greater part of the addi-
tional positive charges aro neutralized by negative
charges associated with unoccupied octahedral sites,
and there is only a slight positive charge on the octa-
hedral layer to be neutralized by an equivalent negative
charge in excess of 1.00 on the tetrahedrnl layers. In
these formulas, octahedral occupancy ranges between
2.63 and 2.88, and Si is less than 3.00, and ranges
between 2.72 and 2.95. However, in three of the
calculated formulas for protolithionites the octahedral
layer has a negative charge, and Si is greater than 3.00.
Exclusive of one formula in which Si is exceptionally
high (3.43 tetrahedral sites), the range in the number
of tetrahedral sites occupied by Si in the calculated
formulas for protolithionite is from 2.72 to 3.17, approxi-
mately 2.95 ±0.25.

The number of octahedral sites occupied bj r Fe +3 in
the formulas calculated from analyses of protolithionite,
as here defined, is generally higher than that specified
by Hey (1955, p. 208). Hey’s value for Fe+ 3 , 0.75
sites in terms of the half-cell formula, corresponds with

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136

8H0RTEB CONTRIBUTIONS TO GENERAL GEOLOGY

only the lower part of the range for Fe + * found in the
calculated formulas, 0.60 to 1.40. On the other hand,
Hoy’s value for Si, 2.75 to 3.00 in terms of a half-cell
formula, agrees fairly well with the Si content of the
calculated formulas, 2.70 to 3.20. Hey indicates that
protolithionites contain little Fe + *, but more than half
of the analyses had more than 2.5 percent of Fe 2 0, and
one had as much as 7.81 percent of FcjQ».

ZINNWALDITKS

Zinnwaldite was considered an intermediate member
of the lepidolite-protolithionite system by Kunitz
(1924, p. 409), Winchell (1927, p. 274), and Ilallimond
(1925, p. 311), and was not assigned a definite formula.
Hey (1955, p. 208) gives the formula 2 [K 2 (Li,Fe, + *Al)»
(Si,Al)»0*e(F,OH) 4 ] for zinnwaldite, with the observa-
tion that there is often considerable deficiency in the
(Li,Fe +1 ,Al) group, and that typically Li»2, Fc +, « 1)4,
and Si«6)4. On the basis of the Li content in this
formula, the Li content of zinnwaldite is herein defined
as 1.0±0.25 octahedral sites in the half-cell formula,
or 2.00 ±0.50 octahedral sites in the unit-cell formula.
Again a range is given because these micas, as members
of an isomorphous series, contain varying amounts of
li, as well as of the other constituents. This is the
range bracketed opposite zinnwaldite in figure 37. The
defined range in octahedral-site occupancy is equivalent
to a Li a O content of from about 2.50 to about 4.50
percent.

In the zinnwaldite analyses 16-31, table 7, Li 2 0
varies from 2.G2 to 4.18 percent, equivalent to octa-
hedral-site occupancies of 0.80 to 1.16 in the half-cell
formulas. FeO is generally lower than in the proto-
lithionites and not quite so variable, ranging from 6.35
to 12.22 percent (0.37 to 0.79 octahedral sites in the
half-cell formulas). In general, the contents of Li^O
and FeO in these analyses bear a reciprocal relation to
each other: the lower contents of Li 2 0 are associated
with the higher contents of FeO, and vice versa. The
octahedral content of the trivalent cations A1 and Fe + *
in the half-cell formulas for zinnwalditcs is quite con-
stant, varying only between an occupancy of 1 .07 and
1.26 sites, with no apparent relation between octa-
hedral R +3 and Li content. In most of the analyses of
zinnwaldite the amount of Fe 2 0, present is very small,
and octahedral A1 is the greatly dominant U +s cation
in the formulas calculated from these analyses, but
several analyses contain significant amounts of Fe 2 0 3 ,
and in the formulas calculated from these analyses
Fe +3 may occupy about as many or even more octa-
hedral sites than Al. The ranges in octahedral content
of the principal cations in half-cell formulas for zinn-
waldites are summarized in the following expression:

(f‘’itis*o. iotFe£»*o.»o.Lfi.oo ab .M).

Octahedral occupancy in the zinnwaldites is generally
between 2.75 and 3.00. Only 1 calculated formula for
a zinnwaldite (21, table 7) had an octahedral occupancy
significantly lower than 2.75. This formula has an
octahedral occupancy of only 2.62. In most of the
calculated formulas the octahedral charge is negative.
Consequently, Si in these formulas is generally in excess
of 3.00 and ranges from 3.03 to 3.46. However, in 3
calculated formulas (17, 22, and 25, table 7) the octa-
hedral group had a positive charge, and Si was less than
3.00 — 2.82, 2.80, and 2.95. Thus the range in the
number of tetrahedral sites occupied by Si in the
calculated formulas for zinnwaldites is quite wide,
2.80-3.46, or 3.15±0.35.

The amounts of Fe +l and Si in the calculated formulas
herein defined as those of zinnwaldite differ somewhat
from the amounts indicated by Hey (1955, p. 208) as
present in zinnwaldite. Hoy’s value for Fe +l , about
1)4 sites in the unit-cell formula, represents the high
end of the range of Fe +1 present in the calculated formu-
las. The median value for Fe +2 present, in terms of
the unit-cell formula, is much closer to 1.00 (1.10)
than to 1.5 octahedral sites. Hey’s value for Si,
about 6)4 sites in the unit-cell formula , is somewhat
higher than the median and average value for Si found
in the calculated formulas, which is 6.3. Hey’s formula
for zinnwaldite includes no Fe +3 , although his formulas
for protolithionite and cryophvllito both include Fe + *.
As pointed out above, some of the calculated formulas
containing the amounts of Li to be found in zinn-
waldite, as defined by Hey, contain appreciable
amounts of Fe + *.

HKRKOAN nnPIDOI-ITK (CR YOPBYU ,IYK)

The name cryophvllito was given by Cooke (1867,
p. 217) to a micaceous mineral found in the granite
ledges that form the extremity of Cape Ann, Mass.
Cooke’s analyses of two types of this material showed
them to have virtually the same chemical composition.
Later, in 1886, three different types of cryophyllite
from Cape Ann were analyzed by R. B. Riggs (Clarke,
1886, p. 358). These three types were also virtually
identical in chemical composition and were similar to
those analyzed by Cooke, except that Riggs obtained
somewhat higher values for I,i 2 0 — 4.81, 4.87, and 4.99
percent, compared with Cooke’s 4.05 and 4.06 percent.
No other occurrence of a ferrous lithium mica having
a comparable Li 2 0 content has been reported in the
literature. On the basis of these analyses, particularly
those of Riggs, cryophyllite has been considered a
variety of zinnwaldite (Dana, 1892, p. 626, and Hey,
1955, p. 208) with a somewhat higher Li and lower
Fe + 2 content. The relation between cryophyllite and
zinnwaldites is shown in figure 37.

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INTERPRETATION OF LITHIUM MICAS

137

The formula calculated from the average of Higgs' 3 analyses (33, 34, and 35, table 7),

[ (Alo, w Pe^UF g HMg 0 . 0 ,Li^,,) (8i,.M°Al 2 o.4»)0.o(F,OH),l- lw K(N»)?:i« M ,

has a Ii content similar to that of Stevens’ sample 7 (34, table 6), a G-layer lepidolite,

-an -<xm

l (Al|.»Fe^o 1 Mnaf a Li l .M) (8i|.tiAlo. M )Oio(F,OH)tj~ I ' w K(Na,Rb,C9)i^oi 0> »

' ns ’

and does not greatly exceed Stevens’ sample 10 (42, table 6), a 1-layer lepidolite,

[ (Ali.ioTio.mFe^otFe^ftMno^iiLii.to) (Sig.aAl 0 . M )O l o(F,OH) a ] , #I K(Na,Rb,C»)^jg®* t

J.W

in content of R 4; cations. In the formula for cryo-
phyllite, R 4 * is made up almost entirely of Fe 4 *; in
the formula for Stevens’ sample 10, R 4 * is made up
equally of Fe 4 " and Mn 4 ’. These two formulas also
have about the same ocatahedral-R 4 * content, although
in the cryophyllitc formula Fo 4 ’ occupies 0.16 octahedral
sites and in Stevens’ sample 10 only 0.03 octahedral
sites. Thus Li 2 0 content and the relation between
Li, Fe +, (Mg, Mn +1 ), and R+^Al, Fo 44 ) in the material
called cryophyllite are comparable with that in some
lepidolitcs. It is, therefore, recommended that the
material known as cryophyllite be considered a ferroan
variety of lepidolite, and that the name cryophyllite be
discarded.

RELATION BETWEEN ALUMINUM LITHIUM MICAS AND
FERROUS LITHIUM MICAS

The relation between the aluminum lithium micas
and the ferrous lithium micas is ilhistruted in figure 39
(which combines fig. 33), which shows the Li, R 4I (Fe 41 ,
Mn 4 *, Mg), and octahedral R +3 (A1, Fe^-fTi 44 rela-
tion in aluminum lithium micas, and figure 37, which
shows the same relation in ferrous lithium micas.
Lepidolites are aluminum lithium micas and, as such,

were discussed with other aluminum lithium micas,
and their composition was interpreted as if derived
from muscovite by replacement of octahedral A1 by Id.
However, figure 39 shows that complete, or almost
complete, replacement of Fe +} in siderophyllite also
produces lepidolites. Thus the lepidolite composition
can be interpreted as the result of two different series
of replacements.

The following equations show the general course of
evolution of lepidolite from muscovite and from sidero-
phyllite, using the average Li-(octahedral Al) and
Li-Fe 44 replacement ratios found in the natural micas:

Muscovite to lepidolite
o.oo -1.00

Muscovite. -[Alj.oo(8i|.coA!|.oo)Oio(OH)j]" 1-otl K .tfc 00

Lithian — o.io -o.oo

muscovite ■ -[ (Ai l .y>Lio.3o) (Si>.i 0 Alo.9o)O l o(OH > P)

2'M

Mixed structures

-0.30 -0.70

Lepidolite.. [(Al 1 . 40 Li l . (0 )(Si,.„A] 0 . 70 )0 1 o(F,OH) J l-‘ 00 K I ^ 00

2W *

Siderophyllite to lepidolite

Siderophyllite {(P^S^CSij.o^li.islO.oIOH),]-' 00 K.tk 04

T5T

Protolithionite — — — )aj Kitob M

2 *7

Zinnwaldite — 100 Kf ^°°

2,'nO

Lepidolite -o.oi -0.30

(ferroan) [ (Rj KfV°

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138

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Replacement of octahedral A1 in muscovite by Li in
the ratio of 2 Li for 1 octahedral A1 leads to poly-
lithionite,

- 1.00 0.00

[(Al|.iwLi;.n>) Si4.ooOn)Fa]~ l '°°

3.00

as the high-Li end of the series, but in the natural
aluminum lithium micas studied the replacement ratio
varied between 2 and 3 Li for 1 octahedral Al. In the
series above, therefore, the replacement ratio used is
2.5 Li for 1.0 octahedral Al. At this replacement
ratio the greatest number of octahedral sites that Li
can occupy is 1.68, with Al occupying 1.33 sites.
Among the formulas for lepidolite, only 2 (57 and 58,
tabic 6) had a higher Li occupancy, 1.84 and 1.93 sites,
respectively. In these 2 formulas the Li-(octahcdral
Al) replacement ratio is 2.0, and they are close to poly-

lithionite. Aside from these 2 formulas, the lepidolite
formula having the highest Li occupancy is 56, table 6,
in which Ij occupies 1.68 sites and Al(+Mn +I ) occupies
1.30 sites, and the Li-(octahedrul Al) replacement ratio
is 2.4. This formula, therefore, is almost identical with
that of the high-Li end of the series shown above, in
which the Li-(oetahedral Al) replacement ratio is 2.5.

The series of form >i las shown for the evolution of
lepidolite from siderophyllite is bused on the averages
of the formulas at hand for siderophyllite, protolithio-
nitc, and zinnwalditc. The generalized formulas for
these averages show an average replacement ratio of
2.0 Li for 1 .5 Fe +J . Extension of this series of formulas
at the same replacement ratio to the highest Id occu-
pancy produces a formula,

331 ’

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INTERPRETATION OF LITHIUM MICAS

139

which is close to polvlithionite and very like the formula
for 57, table 6,

l(Al|,asR^^Ll|, 8< ) (Si3 i8S °AIo. 1 7)Oio(F,OH)d- |c>0 K(Na,Hb,Cs)itco 00

These two scries of formulas, one starting with musco-
vite, the other with siderophyllitc, produce formulas for
lepidolite that have the same Li occupancy but which
differ considerably in octahedral-R +3 occupancy. They
also differ in Fe +I content, but this is not so significant
as the difference in octahedra!-R + * content, because the
ferrous lithium micas themselves differ considerably in
Fe +I content and could produce a lepidolite containing
little or no Fc +3 . On the other hand, the octahedral-
R +J content in the lepidolite formulas and the range of
octahedral-R +3 occupancy found in ferrous lithium
micas may serve to suggest the source of certain lepid-
olites.

In some of the calculated formulas of lepidolites in
which Li occupies fewer than 1.60 sites, octahedral A1
is higher than that found in any of the calculated for-
mulas for siderophyllitc, protolithionite, or zinnwaldite.
Such lepidolites may be interpreted as derivations of
muscovite. In other lepidolite formulas having fewer

- 0.88

KAIo.MTio.o 1 Fei£o 1 fr e ixuiMgi.«t | ii).ai) (Sii.

U»

resembles that of a phlogopite in which about 0.84 Mg

-o.io -o.s

[(Alo.mTio.01Fft1fotFe1xo1Mg1.77) (Sij.ijil
3.80

The deficiency in the amount of positive charge carried
by the Li cations results in a negative charge on the
octahedral layer, which necessitates an equivalent de-
crease in the negative charge on the tetrahedral layers.
The sample is very low in both octahedral and tetra-
hedral Al, and Si, which occupies almost all the tetra-
hedral sites, is quite high. This specimen is very close
to the ideal high-Li end member of a hypothetical
phlogopite-tacniolite series,

0. 00 -1.00

[Mgj oo(8i».ooAli.oo)Oio(OH)}] -,,#0 KfJo 00
[( Mgi.snhin.8o) (8ia.»oAlo.to)Oio(OH)a)~ l ' w KifJo 00

3.00

[(Mgi.onI‘i l .tw)8hO,o(OH)}]- |,co K, + Jo«

* Too

This specimen has a 1 -layer structure (monoclinic kemi-

than 1.60 sites occupied by Li, octahedral Al occupancy
is comparable with that in calculated formulas for
siderophyllites and ferrous lithium micas in which
octahedral R + * is made up almost entirely of Al. Such
lepidolites can be interpreted as possibly derived from
siderophyllitc. The very low Fe +S content of these
lepidolites indicates, however, a highly aluminian
siderophyllitc as the possible source. None could have
been derived from siderophyllitc containing significant
amounts of Fe +3 , or from aluminian lepidomclane, as
can some of the protolithionites and zinnwaldites.

In the two lepidolite formulas in which Li occupancy is
greater than 1.70 sites (57 and 58, table 6), the lepido-
lites they represent can be interpreted as having been
derived either from muscovite, at a Li-(octahcdral Al)
replacement ratio of 2:1, or from sidcropkyllite.

UNUSUAL LITHIUM MICAS

Four analyses of lithium micas can not be interpreted
as if derived by replacement from either muscovite or
siderophyllite. One of these is the analysis of the rare
mica, taeniolite, made by Stevens (Miser and Stevens,
1938, p. 106) from Magnet Cove, Ark. (1, table 5).
The formula calculated from this analysis,

0.03

rAto.ca)Oio(F I OH)2]~ , ' 01 (K 0 .*},Nao.o»)a*» W i

lad been replaced by 0.84 Li,

lo.»i)0|o(OH)J] _,> •® 7 (Ko.#i < Nao.o«)^M , *•

hedral), as determined by Hendricks and Jefferson
(1939, p. 758).

Tabus 5. — Analytes of lithian micas that do not fit in the aluminum
lithium or ferrous lithium series

eio,

63 82

42.02

35. 81

30.97

TIOi

.11

1 3S

1.40

2.04

A laOt

1. 29

18. 75

20.03

17.51

FejOi

.40

.66

.13

2.26

Fed

.24

8.29

21.85

14.81

MnO

.27

1. 19

.22

MpO ...

19.18

9. 55

6.23

8 45

OaO

.93

1.1,0

3 10

1.20

.93

.65

.04

.73

.45

KjO

ia44

8.54

9.(9

& 48

KhiO

I.S5

L 48

(Vo

.47

1. 12

HiO-

.00

. HI

1 1.87

.76

{

.32

n,o+

.39

AS*

2.44

4.34

2. 48
A 17

103.40

101. 55

99.27

101.01

(O-F)

-a eo

-1.83

-.32

— L 33

S9.W

99.72

88.W

SO 08

1. M vnet Core, Ark. (Mbtt anil SUrens, 1838. p. 10*). Associated with clay and
nnvaculU*.

i. Klncs Mountain, S.C. (Hess and Stevens, 1837, p. 1044, analysis 1). From mloa
»chut nt contact with jpodumene pacmatlto.

3. Middletown, Conn. 'Dana, l M3, n. MO, analysts!#).

4. Tin Mountain, S. Dak. (Hess and Stevens, 1837, p. 10(4, analysis 2).

Digitized by Google

140 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The formulas calculated from analyses 2, 3, and 4, table 5,

-o. 20 -aw

KAlo.nTio.QTFcj; so M gi ,oa (8ii.i>^AIo ^s)Q io(0 H,F) 2 ] *' l *K(Na,Rb i C«,Ca/2)^o^ ,

[ (Alo.MTio.otF^SiFcitLMgo.wM no ogLio ;8) (Si 3 7 1 Al l t8 )Oio(OH,F) 2 | 101 K(Na)i*oi°*, and
Z.M

+0. 18 —1. 18

[ (AI<i.8»Ti(i.nFfeo , .*3Feoi| < M|jio.teMno;oiLio ii o) (8ia.t|Al l ,n)O l o(OH,F)i) I0 ®K(Na,Rb,C8)i 06 >

Z78

respectively, resemble biotites in which some Fe +l , or
Mg, has been replaced by Li.

SUMMARY

The composition of most lithium micas can be inter-
preted as if derived from muscovite, by the replacement
of octahedral A1 by Li, or from sideropliyllite, by the
replacement of Fe + * by Li. In the aluminum lithium
micas Li replaces octahedral Al in ratios varying be-
tween 2 and 3 Li for 1 octahedral Al, with an average
replacement ratio of about 2.5. Increasing Li con-
tent is, t herefore, accompanied by increasing octahedral
occupancy, from 2.00 in muscovite to about 3.00 in
some lepidolites. Correlation of calculated formulas
with the structural work of Hendricks and Jefferson
and of Levinson indicates that a change in structure to
the lepidolite structure takes place when the octahedral
occupancy is about half way between 2.00 and 3.00 and
Li occupancy is about 1.00 (equivalent to about 3.75
percent LijO). Because of the disparity between the
amount of positive charge carried by the replacing Li
cations and the replaced Al cations, increase in Li con-
tent is also accompanied by increase in the amount of
negative charge on the octahedral layer and by decrease
in tetrahedral Al and increase in Si, with consequent
decrease in the negative charge on the tetrahedral
layers. Thus the chemical characteristics of the
aluminum lithium micas with increase in Li are: decrease
in both octahedral Al and tetrahedral Al, increase in Si,
and increase in octahedral occupancy. However, the
aluminum lithium micas are not members of a contin-
uous series; the series is broken at about the halfway
point by the structural change necessitated by increase
in octahedral occupancy.

Starting with sideropliyllite (ferrian sideropliyllite,
or aluminian lepidomelane), the ferrous lithium micas
form a series in which Li progressively replaces Fo +i in
an approximate ratio of 2.0 Li for 1.5 Fe + *. Ferrous
lithium micas in which Li occupies fewer than 0.25
octahedral sites are termed lithian siderophyllites,
lithian ferrian siderophyllites, or lithian aluminian

lepidomelanes, depending on the Fc + * content; those in
which Li occupies between 0.25 and 0.75 sites are
defined as protolithionites; those in which Li occupies
between 0.75 and 1.25 sites are defined as zinnwaldites;
and those in which Li occupies more than 1 .25 sites are
considered lepidolites. Thus the high-lithium mica
described by Cooke, and named cryophyllite, is con-
sidered a ferroan lepidolite. The greatest number of
octahedral sites that can be occupied by Li, at the
approximate Li-Fc +2 replacement ratio and at the
average octahedral R + * content found in these micas,
is 1.85,

( (RcctFe^| l Li|.m) (Si3. re Alo.n)0|o(F,OH) a |~ 100 Kfoo 00 -

Joi

In siderophyllites and protolithionites, R + * may consist
entirely of Al or may contain significant amounts of
Fe +I , but in most zinnwaldites R +a is made up predomi-
nantly of Al. Fc +, is low- in all the lepidolites. In
this series, as in the aluminum lithium mica series, in-
creasing Li content is accompanied by increasing octa-
hedral occupancy, but the increase is not as great, and
the ferrous lithium micas are trioctahedral throughout,
except, perhaps for some siderophyllites and proto-
lithionites in which octahedral occupancy is less than
2.50. Increase in octahedral negative charge and
decrease in tetrahedral negative charge also accompany
increase in Li content. Thus the compositional char-
acteristics of the series are increase in Li content,
decrease in Fc +1 content, decrease in octahedral Al
content, and increase in Si content.

The two series join in lepidolite. Lepidolites derived
from sidcrophyllitc would be expected to be lower in
octahedral and tetrahedral Al, for the same Li content,
than lepidolites derived from muscovite; they would
also be higher in Fc + *, although not necessarily, as the
ferrous lithium micas vary considerably in Fe + * content.
The ideal end member of both series is polylitluonite,

1 (Al| cgLii.ool Sn.ouOioKi] 100

300

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INTERPRETATION OP LITHIUM MICAS

141

REFERENCES CITED

Berggren, Thelma, 1940, Minerals of the Yarutrfisk pegmatite,
pt. 15 — Analyses of mica minerals and their interpretation:
Geol. Fflrcn Stockholm FOrh., v. 62, p. 182-193.

1941, Minerals of the Varutr&sk pegmatite, pt. 25 —

Some now analyses of lithium-bearing mica minerals:
Geol. F6ren. Stockholm Ffirh., v. 63, p. 262-278.

Buryanova, K. S., 1940, An account of the mineralogy of granite
pegmatites from the Korosten plutone massif in Volhynia
and of a study of their iron biotites: Mincrulog. obaheh.,
Leningrad, Zapiski, ser. 2, v. 69, p. 519-540.

Clarke, F. W., 1886, Researches on lithia micas, pt. 2 — The
iron-llthia micas of Cape Ann: Am. Jour. Sci., 3d ser.,
v. 32, p. 358- 381.

1910, Analyses of rocks and minerals from the laboratory

of the U.S. Geological Survey, 1880-1908: U.S. Geol. Survey
Bull. 419, 323 p.

Cooke, J. P., Jr., 1867, On cryophyllite, a new mineral species
of the mica family, with some associated minerals in the
granite of Rockport, Massachusetts: Am. Jonr. Sci., 2d

ser., v. 43, p. 217-230.

Dana, E. S., 1892, The system of mineralogy, 6th od.: New
York, John Wiley and Sons, 1 104 p.

Duparc, I-ouis, Wonder, M., and Sabot, R., 1910, Ia-s mingraus
dea pegmatites des environs d’AntshirabS a Madagascar:
Mem. Soc. phvs. et histoire nat. Gendve, v. 36, p. 363-410.

Foster, M. D., 1956, Correlation of dioctahedral potassium
micas on the basis of their charge relations: U.S. Geol.
Survey Bull. 1036-D, p. 57-67.

1960, Interpretation of the composition of trioetahedral

micas: U.8. Geol. Survey Prof. Paper 354—1$.

Ginzburg, A. I., and Rcrkhin, S. I., 1953, On the composition
and chemical constitution of the lithium micas: Mincralog.
Muzeya. Akad. Xauk U.S.S.R. Trudy, v. 5, p. 90-131.

Hallimond, A. F., 1925, On the chemical classification of the
mica group, I. The acid micas: Mincralog. Mag., v. 20,
p. 305-318.

Heinrich, K. W., and I-evinson, A. A., 1953, Studies in the mica
group; Mineralogy of the rose muscovitcs: Am. Mineralogist
v. 38, p. 25-49.

Hendricks, S. B., and Jefferson, M. E., 1939, Polymorphism of
the micas: Am. Mineralogist, v. 21, p. 729-771.

Hess, F. I.,, and Stevens, R. E., 1937, A rare-alkali biotite from
Kings Mountain, North Carolina: Am. Mineralogist, v.
22, p. 1040-1044.

Hey, M. H., 1955, An index of mineral species and varieties, 2d
rev. ed.: Tendon, British Museum (Nat. History), 728 p.

Kunitz, Wilhelm, 1924, Die Hexichungcn zwischen der chemischen
Zusammensctxung und der physikalisch-optischen Eigen-
schaften innerhalbderGlimmergruppe: Neues Jahrb. Miner-
alogie. Geologle, u. Palftontologie, Bellage-Band 50, p.
365-413.

I^vinson, A. A., 1953, Studies in the mica group; relationship
between polymorphism and composition in the muscovite-
lepidolite series: Am. Mineralogist, v. 38, p. 88-107.

Litvin, O. I.., 1956, The lithium-ferrous micas from pegmutites
of Volhynia: Kiev Perzhav. Univ. Nauk. Zapiski, v. 15,
no. 2, Zbirnik Geol. no. 6, p. 119-128.

Marshall, C. E., 1949, The colloid chemistry of the silicate
minerals: New York, Academic Press, 195 p.

Meng, H. M., and Chang, K., 1935, Geology of the Hsianghua-
ling tin deposits, Lingwu, Hunan: Nat. Research Inst.
Geology (Acad. Sinica), Mem., no. 15, p. 15-72.

Miser, 11. I)., and Stevens, R. E., 1938, Tacniolite from Magnet
Cove, Arkansas: Am. Mineralogist, v. 23, p. 104-110.

Nockolds, S. R., and Richey, J. E., 1939, Replacement veins in
the Mourne Mountains granites, N. Ireland: Am. Jour.
Sci., v. 237, p. 27-17.

Pehrinan, Gunnar, 1945, Die Granit|>egmatite von Kimito
(S.W.-Finnland) und ihre Minerale: Acad. Aboensis math
et phvs. Acta 15, no. 2, 84 p.

Saldanha, Reynaldo, 1946, O estudo da jazida de wolframita de
Inhandjara: Bfto Paulo Univ., Fac. Filosofia Bol. 60 (Min-
eralogies, no. 8), p. 1-95.

Schaller, W. T., 1930, Adjectival ending of chemical elements
used as modifiers to mineral names: Am. Mineralogist, v.
15. p. 500-574.

Shibata, II., 1952a, 8|>odumenc and ambligonite from the Bunsen
Mine and other locality's in Korea: Tokyo Bunrika Daigaku,
Sci. Itepts., sec. C., v, 2, no. II, p. 145-154.

1952b, Mineralizations in granite-pegmatites in Japan

and Korea: Tokyo Bunrika Daigaku, Sci. Repts., sec. C.,
v. 2, no. 12, p. 155-206.

Shilin, L. L., 1953, On lithium micas from pegmatites of alkaline
magmas: Mineralog. Muzeya. Akad. Nauk U.S.S.R. Trudy,
v. 5, p. 153-163.

Simpson, E. S., 1927, Contributions to the mineralogy of Western
Australia: Royal Soc. Western Australia Jour., v. 13, p.
37-48.

Smith, J. V., and Yoder, H. 8., Jr., 1956, Experimental and
theoretical studies of the mica polymorphs: Mineralog.
Mag., v. 31, p. 209-235.

Stelzner, A. W., 1896, Contribution on the lead ore of Freiberg
and the tin ore of the Erzgebirge: Zeitschr. prakt. Geologie.
v. 4, p. 377-412.

Stevens, R. E., 1938, New analyses of lepidolites and their
interpretation: Am. Mineralogist, v. 23, p. 607-628.

Stevens, R. E., and Schaller, W. T., 1942, The rare alkalies in
micas: Am. Mineralogist, v. 27, p. 525-537.

Tsvgnnov, E. M., 1954, The lithium miens of Volhynia: .Mincr-
alog. Obshch., Ia-ningrad, Zapiski, ser. 2, v. 83, no. 4, p.
383-397.

Ukai, Yasuo, Nishimura, Khinichi, and Hashimoto, Yoshikazu,
1956, Chemical studies of the lithium micas from the
pegmatite of Minagi, Okayama Prefecture: Mineralog.

Jour. Japan, v. 2, no. 1, p. 27-38.

Walker, T. L., and Parsons, A. I.., 1924, Pegmatite minerals
from New Ross. Nova Scotia: Toronto, Univ., Studies.
Geol. ser., no. 17, p. 46-50.

Wells, R. C., 1937, Analyses of rocks and minerals from the
laboratory of the United States Geological Survey, 1914-
1936: U.S. Geol. Survey Bull. 878, 134 p.

Winchell, A. N„ 1927, Further studies in the mica group: Am.
Mineralogist, v. 12, p. 267-279.

1942, Further studies of the lepidolite system: Am.

Mineralogist, v. 27, p. 114-130

142

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Table 6. — Analyses, with data for writing formulas, of aluminum lithium micas used in interpretation of composition

(In order of increasing LliO content)

Analysis *

33...

38 ...

39 ..

40 ..

12 .

47 .

52.

Percent

SiOl

AljOj

TIOi

Ft-iOi

FcO

MgO

MnO

LUO

c»o

N*a»0

KjO

RbiO

Cf,0

H»0+

n*o-

45. 51

36.36

0. 07

0.25

002

0.07

0 . so

0. 06

0.09

0.57

10.76

4 35

0.65

0.62

44.85

37.20

.45

Tr.

.02

.07

.22

1. 10

10.20

4.35

.00

.79

44. 10

33.04

. 14

2.95

.50

.33

.03

.24

.36

.78

9.73

6.90

1.04

.66

46 22

37.46

Tr.

.56

.38

.71

.32

.10

1. 19

10. 71

3.6

.73

44 SO

37.72

.67

.38

.91

10.07

0.82

0.09

4.52

.20

42 30

33.50

.05

.97

1.20

. 16

.01

.40

.94

.96

0.31

6. 85

4.09

.37

45. 03

36.33

.02

. 14

.02

.06

.41

.09

.69

10.50

.79

4 X

.79

1.01

43.68

32.54

. 14

2.62

1.63

1.06

.46

1.05

8.M

.53

<.20

385

Z 48

1.00

45. 24

30.85

.01

.09

.02

.08

.12

.49

.00

10. 08

.03

.*J0

4. 12

.46

.91

46 60

35 1*

JXJ

. 10

.02

.05

.37

.63

.OH

.50

10.52

4.81

.44

1.31

V. 01

35. 64

.00

.13

.00

.04

.09

.69

1.12

1.88

8* 19

1.20

.20

4.65

.08

.54

48. 18

35. 76

.15

.00

1.52

.07

.11

.73

.00

9. 95

.57

Tr.

4.4$

.3H

.88

46.17

35.57

.00

.15

.os

.00

.04

.70

.00

10.37

1.1

4.06

. 12

.75

.70

.CO

. 60

. 51

5 90

3 M

3 00

.07

47.64

34.22

.00

.10

.28

.05

1.10

.00

.47

10.40

.33

.75

362

. 10

1.21

46.24

32. 37

. 10

1.34

1. 14

. 19

.09

1. 1

. 10

.79

10. 16

1.3

341

.69

1.41

41 62

32. 58

. KS

.94

. 10

.00

1.61

.68

.3)

9.60

6.50

4 V8

1.02

43 24

33.90

.24

.65

1.3$

.26

.01

1.63

.90

.12

10. 21

300

2 30

.05

46.3 0

33.08

.00

1.20

.14

.2$

1.80

.00

.63

10.09

1.37

.41

3 06

.34

2.06

46. 34

32.47

.C6

.00

1.06

.00

.35

2 45

.36

9.40

1.5

3. 32

.32

Z 82

47. CO

30.00

Tr.

.26

.41

. 13

2. 04

2.70

Tr.

.77

0 52

1.93

. 1M

2 18

.25

4.09

49.50

28. 06

Tr.

».ll

.00

.54

3. 51

.00

1.27

10.32

1. 11

.13

2. 15

.27

5 W

4S. 5S

28.93

Tr.

•.04

.IX)

.92

3.70

Tr.

.87

10.02

.91

. 16

2.56

.54

4. 93

53. 30

28. 18

Tr.

*. 04

.IX)

.28

3. 81

Tr.

.64

9.91

1.55

.11

Z 18

.18

4.97

40. 52

28. 8U

.40

.24

.1X2

.07

3. 87

.13

8 82

3 73

1.7

5.18

43. 63

29.02

.00

.10

.(O

.00

.28

3.9

.IX)

1.3

to. os

1.5

1.64

4.50

50. 30

25 49

Tr.

1.30

3.90

.24

.95

10.13

1.39

.17

1.84

.08

6.03

49. 14

27 06

.00

>. 43

.1X5

1.22

3.95

Tr.

.40

10.13

1.17

.62

2 6

6 21

40. 29

28. 40

Tr.

*. 05

.12

.66

S.iO

Tr.

.77

9 93

1.66

.12

1.76

,i«

6 52

40. 62

27.30

.31

.07

.56

4.34

2 17

s. »:a

2 44

.72

1.6

5.45

51. 52

25.96

.31

.02

.20

4 9)

. 16

1.06

11.01

1)5

6.80

43. 94

22.21

.00

1.55

1.52

.03

.75

4.99

.10

.63

8.«2

3. ft

1.08

1.46

a 83

6 09

53.45

22 15

Tr.

*. 16

. 14

.52

6. 01

.00

.74

9. 58

1.56

.48

1.28

7.22

40. 58

23. S7

.ml

*.21

.00

2.78

5.05

.00

.57

10. 14

1.62

.09

1.22

.31

7.49

49. 10

24. SI

.08

*.24

.05

2.5!

5. 10

Tr.

.52

10.25

1.78

. 19

1 .

6.89

51. 69

22.83

Tr.

.€0

.14

5 11

.00

.57

9.53

I 64

.17

1.02

.31

6.66

57 44

15 3>

1.70

Tr.

5. 16

.61

K (.9

4.28

3.68

1.04

51.88

.79

1.99

.00

2.01

6.26

.00

.51

10.55

7.65

23.97

Tr.

*.04

.00

.17

6.33

IV.

.80

10. 79

.42

.41

1.21

•••»

7.76

23. 54

.00

. 46

1.27

.06

.79

5.34

.04

1. 10

10. 97

1 39

.78

6.76

49.28

21.36

.63

.73

.87

536

.26

11.24

.32

.87

392

50.31

19.95

.22

2.55

.02

2.03

5.39

Tr.

.cO

11). 14

.97

.00

.$s

.60

7.65

.24

.88

1.41

5 41

.Of.

.52

9. 82

3.25

3 51

4.61

60.92

2 3 13

.00

.06

.00

.06

.52

.00

.5*

9. 75

2.6

.57

.06

386

51. 10

23. US

Tr.

. 00

. 13

5 51

IV.

.63

10. 25

1.38

■ 4R

l.W

.73

7.36

.40

I 32

5 57

.67

.72

10 IN

.05

2.96

3. <8

32$

52.68

22.82

Tr.

.01

.00

.28

5 64

Tr.

.50

io. li

1.04

. 67

1.35

.30

7.56

.42

. 16

1. 24

1.77

567

.26

.06

10.37

3.94

356

393

50. O)

25.42

.00

.28

.(C>

.00

.15

5 7

.00

.35

9.08

3.2

.93

.70

.09

3 15

51.26

23.71

.01

*. 07

.61

5 78

Tr.

.65

9 9<>

2. CO

.08

.9)

.34

8.08

51.67

23.22

.06

•. 0*

.30

1.37

5 83

.00

1.03

11. 18

.44

$ 22

51.07

n 05

.06

*.23

. 00

.76

5 SO

Tr.

.82

9.70

1.3$

.09

7.13

40. H'J

25.56

.00

.08

.00

.22

.38

5 95

.00

9. 67

1.07

1.2

.38

.»

385

51. 01

17. 95

.02

*.21

.30

2*06

6.18

Tr.

.72

10.28

1.22

.24

.6S

.81

9. 19

58.56

14.97

.36

.43

1.30

.14

6 31

.22

10.03

372

.88

4.34

52 67

23.01

.08

.63

6 37

.90

11. 10

.fi

8.26

57.03

15.55

.03

>. 12

.22

.72

584

Tr.

.44

10.05

1.35

.40

.49

.74

9 no

50.56

12.01

.48

.13

.42

.34

.03

7.26

Tr.

.53

11.04

1.14

None

.47

.73

7.73

Koto and footnotes at end of table.

Digitized by Google

INTERPRETATION OF LITHIUM MICAS 143

Tablx 6. — Analyst*, with data [or writing formula*, of aluminum lithium mica* used in interpretation of composition — Continued

(In order of Increasing UiO contend

Analysis >

Percent

Octahedral positions occupied by-

Octa-

hedral

charge

Tetra-

hedral

chart*

Composite

layer

charge

Interlayer rations

Total

O-F,

Adjusted

total

Fe**

F«r*>

Mn*»

Total

Charge

Por-

tions

100.11

-0.26

99.85

1.92

0.00

0.01

0.00

a oi

0.06

0.02

2.01

-0.07

-0.95

-1.02

+1.00

1.00

100.30

-.33

90. 97

1.94

.00

.02

.03

.00

.02

2.01

-.04

-1.00

-1.04

+1.05

1.03

100.30

-.24

100.06

1.75

.01

.16

.03

.00

.07

2.04

-.07

-.95

-1.02

+1.02

.99

101 06

-.31

100. 75

1. 88

.00

.03

.04

.08

2.07

-.06

— 1.02

— 1.08

+ 1.06

1.05

1 100.39

-.08

100.31

1.93

.03

. io

*2.07

+.01

— 1.02

—1.01

+1.00

1.00

101. tl

100.95

1.81

.00

.05

.07

.02

.12

2.07

—.12

— 1.00

— 1. 12

+1. 12

1.05

100.90

-.42

100.48

1.90

.00

.01

.00

.06

.02

.11

2.09

-.02

-.96

-1.00

+1.00

.99

ICO. 13

-.42

99.71

1 68

.01

. 14

.09

. 11

. 13

2. 16

+.03

-.98

—.96

+.95

.95

100. 24

-.38

96.86

1.93

.00

.01

.13

2.08

-.04

-.97

-1.01

+.»

.99

100.51

— . 55

99.95

1.90

.00

.01

.CO

.00

.02

.17

2.10

-.05

-.94

-1.00

+.09

• OS

100.46

-.23

100.23

1.86

.00

.01

.00

.01

.18

206

-.19

-.94

-1.13

+1.15

1.07

100.66

-.37

100.29

1. 86

.01

.00

.08

.01

.20

217

+.02

-.97

-.95

+.W

.99

100.04

-.33

99.72

1.89

.00

.01

.00

.20

2 10

-.10

-.91

-1.01

+1.01

1.01

100. S5

-.03

100.82

1.60

.02

.25

.04

.02

.00

.23

2 16

-.02

-.97

— .90

+. w.

.91

100. 29

-.51

99.78

1. 84

.00

.03

.00

.29

216

-.84

-.97

+.98

.98

100.63

-.50

100.04

1.71

.00

.07

.06

.02

.01

.30

217

-. 18

-.87

-1.05

+ 1.06

1.04

100.77

-.43

100.34

1.74

.02

.05

.06

.01

.00

.44

232

+.03

-1.02

—.99

+1.03

.98

18.

100.71

-.02

100. w

1.73

.01

.03

.08

.03

.00

.42

230

-.04

-1.02

-1.06

+1.05

.9S

100.70

-.87

90. Hi)

1.73

.00

.07

.01

.02

.48

2 31

-.13

-.89

-1.02

+1.02

1.03

101.21

-1. 19

100.02

l.tt

.00

.(X)

.C«l

.00

.02

.66

2 43

-.11

-.fe

-.99

+ 1.03

1.01

102. C«S

-1.72

100.34

1.5S

.00

.01

.02

.01

.12

.73

2 47

-.20

— .84

-lot

+ 1.01

1.01

102.95

-2L52

100. 43

1.52

.01

.00

.03

.94

2 50

-. 42

— .80

—1.11

+ 1. 10

1. 10

102. 16

—2.06

100.08

1.54

.00

.05

1.00

259

-.28

—.74

-1.02

+1.01

1.01

102.05

-2.09

99.06

1.54

.00

.02

1.01

257

-.33

-.66

-.99

+.99

.99

102.71

-2.18

100.53

1.65

.02

.01

.00

1.03

2 01

-.20

—.71

-.91

+■94

.93

102 02

-1.94

100.08

1.54

.00

.01

.00

.02

1.04

261

-.27

-.78

-1.05

+1.08

1.0S

102 78

—2.54

100. 24

1.40

.00

.08

.Oi

.03

1.05

2 60

-.45

-.62

-1.07

+1.09

1.08

102.62

-2. 19

100. 43

1. 49

.00

.02

.00

.07

1.06

2.64

-.29

-.70

— .99

+.96

.Sfc

103 27

-2.75

100.62

1.51

.00

.01

.04

1.06

2 62

-.31

-.72

-1.03

+ 1.02

1.03

102. 62

-2.29

100. 23

1.44

.02.

.00

.03

1. 1ft

2.65

-.40

-.6*

-l.CS

+ 1.09

1.09

101.89

—2.44

99. 46

1.39

.02

.00

.02

1.29

2.72

-.44

-.52

-1.06

+1.08

1.07

103. 15

— 2.S2

100.33

1.21

.00

.08

.09

.00

.04

1.39

2.81

-.48

-.60

-1.08

+ 1.06

1.05

102. 7H

—3. 04

99. 74

1.32

.CO

.01

.03

1.35

2.72

-.50

-.42

-1.01

+.99

. 99

34 .

103. 19

-3. 15

100.04

1.29

.00

.01

.CO

. 16

1.38

2.81

-.41

-.62

-1.03

+ 1.03

1.03

102.82

-2.9)

99.92

1.32

.00

.01

.00

. 14

1.39

2.86

-.35

-.67

-1.02

+ 1.03

1.03

102.

-2.^9

100. 09

1.36

.00

.01

.CO

.01

1.35

2.73

-.53

-.41

-.91

+.94

.01

*99.70

-.43

99.27

1.12

.03

.17

.00

1. *0

272

-.81

-.12

— .93

+.83

.88

34.

103.39

-3.22

100. 17

1. 16

.01

.04

.ii

.00

.12

1.43

287

-.47

-.49

-.9*

+.0S

102. 08

-3.27

99 71

1.34

.00

.CO

.00

.01

1.44

279

-.52

-.55

-1.07

+ 1.00

1.06

» 102.70

99 . M

1.26

.00

.02

.07

.01

.04

1.45

2.85

-.47

—.62

— 1.09

+ 1.C9

1.09

103. Vi

-3. 76

99. 71

1.26

.03

.07

.06

1.45

2 SO

-. 14

-1.12

+1. 10

1.08

102. 51

-3.22

99. 29

1.10

.01

.02

.15

.00

.16

1.50

2.93

-.50

-.52

-1.02

+.09

.99

102. 17

-2.16

11)0.01

1.19

.00

.02

.01

.09

.08

1.50

2.S9

-.51

— . CO

-1.11

+ 1.08

1.01

44 ..

102.64

-2.B9

99. 75

1.36

.00

.03

1.47

2.S6

-.39

-.61

-1.00

+ 1-00

1.00

45 .

102

-3. 10

99 78

1.34

.00

.CO

.00

.01

1.49

2 84

-.47

-.56

-1.03

+ 1.03

1.03

100.51

—2.22

98. 32

1.40

.01

.02

.01

.03

.07

1.41

2 95

-.07

-.92

-.90

+1.00

.85

102. 95

-3 IS

99. 77

1.31

.00

.O')

.(X)

.02

1.52

285

-.51

-.40

-1.00

+ 1.01

1.00

101.83

-2.50

90.33

1.10

.01

.02

.01

.13

.1!

1.62

3.00

-.48

-.49

-.97

+.W

.97

49 ...

102. 76

-2.59

100. 17

1.36

.00

.01

.0)

.00

.01

1.53

2 91

-.34

— . 64

-.98

+.8S

.08

OT . .

103 46

-3.40

100. 06

1.3)

.00

.0)

.01

.03

1.56

2 90

-.46

-.57

-1.03

+ 1.02

1.02

103.36

-3. 40

99 O')

1.24

.00

.03

.08

1.55

2 90

-.51

-.57

- 1.08

+ 1.08

1.08

100.23

-3 no

97.23

1.25

.00

■ 01

.01

.04

l.ftl

2 92

-.52

-1.04

+ 1.02

1.02

102 96

-2.80

100. 07

1.33

.00

.02

1.59

2 96

-.34

-.68

-1.02

+.99

.90

54 .

104. 16

-3.87

100. 29

1. 10

.00

.01

.03

.12

1.68

2 9!

—.70

-.33

-1.03

+ 1.04

1.04

65 ...

* 103. 10

-1.83

101.27

1.01

.02

. 13

.01

1.67

2 SO

— . 8S

-.15

-1.03

+1.09

1.02

103. 55

-3. 48

100. 07

1. 26

.00

.04

l.Gft

2 98

-.46

-.53

-.99

+ 1.05

1.06

• 103. 72

-3.79

99. 93

1.05

.00

.01

.02

.04

1.84

2 96

-.87

-. 17

-1.04

+ 1.04

1.04

• 103. *3

-3.26

100. 17

.88

.02

.01

.02

.03

.00

1.93

*293

-1.02

-.06

-i.oe

+1.05

1.05

Th* numbers In the footnote* below ore In percent. • Includes 0.0J CL

i See descriptions on pore 14* for origin of sample* and source of truly***. • May be present as FetOr.

> Include* 0.21 M nrOi, 00.01 octahedral position. ■ Include* 0.04 PiOj, 0.31 80s, and 0.02 Cl.

* Total Fe reported as FeO. ■ Includes 0.14 Nt»Oi. oO.OO octahedral position.

• Include* 0.09 P»Oi and 0.34 80a 1 Includes 1.33 NbiOa 00.04 octahedral position.

(Note* to table 8 are oo paste 1*4)

Digitized by Google

144

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

NOTES TO TABLE 8

1. Apache, Petaca, N. Me*. (Heinrich andlLevirwm, 1053. p. 43, no. 4>.

2. Russia, locality not given (Glmburg ana Berbkln, 1W3, p. 96).

3. Yamanoo, Txukuba, Japan (Shibata. 1952b, p. 163, no. 12).

4. Londonderry, W'tsurn Australia (Simpson, 1027. p. 46).

ft. Harding mine, 014 mil as east of Embudo, N. Mex. (Wells, 1037), p. 108. B. Cor*
reetions of percentages of alkalies by Stereos and Smaller, IW2. p. 637.

6. Yamanoo, Tsukubo, Japan (Shibata, 1952b, p. 163. no. 11).

7. White Spar mine No. 1, Gunnison County, Colo. (Ilcinjtch and Lovlrwon, 1063,

p. 43, no. 2).

$. Kimllo, southwest Finland (Pchrman. 1045, p. 56).

0. Plttlite, Roeiad*. N. Mtt. (Heinrich and Levinson. 1W3. p. 43, no. ft).

10. Brown Derby No. 1 mine, Gunnison County, Colo. (Heinrich and Levinson,

1933, p. 43. no. 3).

11. Varutrflsk, Sweden fBerfigren. 1040, p. IBS, FI.). Normal muscovite structure.

12. Varutrflsk, Sweden (BcflOtren. 1910. p. 183. O). Normal musoovlte structure.

13. Varutrflsk. Sweden (Bermen, 1941, p. 264 , }). Normal muscovite structure.

14. Nagatare, Fukuoka Prcf., Japan (Shibata, 1952b. p. 164, no. 19).

15. Varutrflsk, Sweden (Bergcren, 1940. p. 185, F>.

16. Varutrflsk. Sweden (Brrcgmi, 1041. p. 264, L). Normal muscovite structure.

17. Butiscn mine. South Kanky6-ruiRd6, Korns (Shibata. 1953b, p. 164, no. 21).

18. Bunsen mine. South Kankyd-nandfi, Korea (Shibata. 1952b, p. 164, no. 231.

19. Varutrflsk, Sweden (Berggren, 1940, p. 185, E). Normal muscovite structure.

». VaratrAvk, Sweden (Bermen, 10*0. p. 185. D). Normal muscovite structure.

21. Manitoba, Cana la (Stevens, 10JS, p. 6l£ no. 1, U.8. NHL Mus. No. 97G35).

Normal mnotrlls structure.

22. Katerina mine. Pala, San Diego County, Calif. (Slovens, 1939, p. 61ft. no. 2).

Transitional structure (combination of form*).

23. Stewart mine, **40 now,'* Pala, San Dl.-*n County. Calif. (Slovens, 1939, p. 615,

no. 3). Traruitbml structure (combination of forma).

24. Pamunii-ParifUsExporitioo mine, Chihuahua Valley, east of Oak Grove. San

Diego County. Calif. (8tevens, 193ft, p. 615, no. 4). Traasitlonal structure
(combination of f-irms).

25. Norway. Maine (Clarke. 1910, p. 287, F).

26. Varutrflsk, Sweden (Berman. 1940, p. 185. C). Normal muscovite structure.

37. Rows, Moravia, Ctcchcelovakla (R. E. Stevens written communication, 1938,

U.8. Oeoi. Survey Lab. Record No. D-789).

28. Mt. ApoMtc, Auburn, Maine (WlnchcU, 1942, p, lift, no. 17, 17.8. Nall. Mas.
No. 8(030).

39. Stewart mine. San Diego County. Calif. (Btevena, 193S, p. 615, no. 5). Trans!*
t local structure (combination of forms).

30. Auburn, Maine (Clarke, 1910, p. 287, D).

31. Black Mountain, Rumford, Maine (Clarke. 1910. p. 237, A).

32. Klmlto, southwest Finland (Pehrman, 1945, p. 59).

33. Stewart mine, Pala. San Diego County, Calif. (8tevena, 1938, p. 61ft, no. 6).

Structure, 6-lnycr loptdclltc.

34. Ohio City, Colo. (St evens, 1038, p. 61ft, no. 7. 0.8. Natl. Mus. No. 97S83).

Structure, 6-layer lepldolit*.

3ft. Ohio City, Colo. (Wlncbell, 1942, p. 115, no. 10).

36. Himalaya mine. Mesa Grande, San Diego County, Calif. (Steven*. 1933, p. 615,

no. 8). Structure, 1-layer trpldolli*.

37. Locality not vlven (Shllln. 1951. p. 165).

35. Wakefield. Queb«. Canada (Wlnchell, 1942. p. 115, no. 26).

39. San Diego mine. Mesa Orande, San Diego County, Calif. (Stevens, 1938, p. 615,

no. 9). Structure. 1 -layer iepldolite.

40. Alnb&sdito, Crab (Wlncnell. 1942, p. lift, no. 13).

41. New Ro», Nova Scotia (Walker and Parvms, 1924, p. 49).

42. Wakefield, Quebec, Canada (Stevens, 1938, p. 615, no. 10). Structure. Mayer

lepidolite.

43. Uruchln, Kflgen-d6, Korea (Shibata, l»52b, p. 165, no. 25).

♦4. Rocxna. Moravia {Bcresren, 1941, p. 271, no. 1).

45. Stewart mine. Pala, Sun Diego County, Calif. (Stevens, 1933. p. 615, no. 11).

Structure not determined.

46. Yogs tare, Fukuoka Pref., Japan (Shibata. 1952b, p. 164, no. 20).

47. Stewart mine. Pala. San Diego County, Calif. (Stevens, 1938, p. 615, no. 12).

Structure, 6-layer lepidolite.

48. Bunsen mine. South Kankyd-nandft, Korea (Shibata, 1062a, p. 150).

49. Utd, Sweden (Ber.'rren. 1941. p. 289).

50. Himalaya mine, Mm* Grande, San Diego County, Calif. (Stevens, 1938, p. 615,

no. 13). Structure, l -layer Icnldolite.

51. Londonderry, Western Australia (Simpeon, 1927, n. 46).

52. Colgourir. Western Australia (Stevens, 1938, p. 615, no. 14). Structure, 3-layer

hexagonal lepldclite.

53. Vonitrflsk, Sweden (Borggten, 1940, p. 185. A). Structure, 6-laycr lepidolite.

M. Little Three mine, Ramona, San Diego County, Calif. (Stevens, 1938. p. 615, no.

16)* Structure, l -layer lepIdoUte.

55. Locality not given (Shilin, 1953. p. 155, no. 2).

56. Londonderry, Western Australia (Simpson, 1927, p. 46, no. IH).

67. Antsonvombato, Madagascar (Stevens, 1938, p. 615, no. 16). Structure, Mayor
lepldoUtc.

58. Kaoscrdluaraik, Jullanehaab district, Greenland (Stevens, 1938, p. 615, no. 17,
0.B, Nall. Mus. No. 94314). Structure, 1-layer lepidolite.

Table 7, — Analyses, i eith data for writiny formulas, of siderophyllites and ferrous lithium mica* used in interpretation of composition

(In order of increasing LPO content)

Armlyf,ls *

810,

AWH

TIOi

re&t

VbO

U. M

Ti SO

n.2!

u.:v

00.08

J3.«u

» 88

-08

l.M

28. VI

3. . ..

n.m

lv. 0:

.31

lli.os

ir.M

17. 24

L 51

tv. 15

30.6 1

18. *3

ti»

.78

? -3

22.il

8..

Sl.'^s

17.08

:.♦«

21.13 ;

V-H»

20. *8

2 m

18.00 !

m. 00

23. (kI

4. 84

1ft 1?

38,00

27. GO

is. •(%

«.«

IS. 01

3. 08

IS »

88.91

IS. 'JO

4.18

21. V?

4170

23. SO

.32

. 50

11.67

:n. 12

22.3;

T,.

7,81

12 *.i3

14 .

4M 26

20.73

*21

tfi 2»

41 76

22, 76

. f|H

H 24

Si.-J

22.2?

. 12

4.40

9.0?

36.5!

18L87

. 14

10. 06

12.22

15. m

22. 0i»

.fkJ

11. (A

45 ?.J

21.78

.47

1L35

tli. 44

31.84

1,11

10.09

it!

«.«

,j«

.32

?.»

3.1.01

Xi TS.

.57

« 10

17.42

23 .

4ft 37

23,45

1.80

10.0©

43 63

38.81

Tt,

1.06

a m

25..,,,

43 SO

l 85

11 VJ

36,,

13. (M

23 34

1.33

12.00

27.

iti.Mi

40.74

21,78

1. 19

10.22

28 .

2SX H’

.97

* > 85

41.60

25.70

.76

H 45

3L,.,,« V

t.H. 40

31.60

.14

7.10

■32

45.98

14.04

.22

A.00

61. 46

10.22

7. 63

34 ....

61.96

ift m

2. 43

r* 32

52, )?

15.39

4. 1 1

5. 90

Note and footnote* at end of table.

Fen cut

MgO

0-4»>

,l(i
.70
28
*2
29
19

L50

.17

.09

Tr.

MnO

9.29

.21

.71

.21
.61
i :..f
.29
1.96
3. 21
.68

Mtt

1.97

1.75

1.73
1. 80

.747

’"35'

4 .02

.73
\ -38
.37

1.74

»-97
% 46
.06
.24

Lt|0

0. 32
.39
.48
.80
.69

1. 19

1. Tj

1 44
1.47

1- 4*
l, 91

2- 40
2.31

2 42

2-70

3.28

3.23

A,m

3 27

3.40

3.41
8. TO
3, TO
3.73
1.72
3,78
4.03

4 18
L&7
4 St
■LF7
4 99

OaO

1.52

. 14

.73

1.10

.48

1.30

.38

.23

Toi

1. 14

.96

.in
.78
. 50
s-:
.43
45
.24
-00

.30

1-80

Tr.

.12

Tr.

Na*0

Tr.
a 46
.21
.27

14
,51

1-01

t.os

1.37

.88

.38

.74

L JO
07
.«

15
.42
.78
,54

Z 45
.71
1 . 2 ?
.82
1.20
1 m
1 n
.54
.96
230
1.12
.35
-69
.87
.63

KjO

8.05
8.90
8.63
7.21
7.m
7.41
8.04
9. 4(1
8.15
9.68
6.23

9.58
H. 60
10 47
10.51
9, ;«s
699
10.46
0. 98

10.58
« 35
8.5)
8.S7
0.41
:.?3
7 66
9.30
10-87

0.11
608
10 45
». VI
tC. 66
10.70
10.48

11,0+

11 ^ 3 -

Total

3 'O

a. 24

2.00

1(0 So

1 t*

.418

«OS91

3.1?

3.21

■j.y,

W. 22

■i- VS

12. ?8

1.87

ICO. 43

S 6 ?

?.JO

t 97

I!*iS3

.V 0/.

2.94

100.81

3 .

* 9ft 17

.08

.54

3. NO

« 1 ' 0.?1

3 121

.04

1.66

101.84

1 .

«. 76

103.38

3. 13

101.17

i.at

5.M

*WL»

.21

W. 64

.80

.in

6.40

* 101.04

1 .

6.46

I 0 LBU

H, 0 »

A.W2

ino.so

3 03

3 74

LTS

101.33

0 .

7.V1

> KM. 43

-W

;.9S
7. n 2

tW.63

103.74

2,27

.54

6 . 1*2

99.3 4

0H. so

*.80

.3?

2 .M

i<;i- <4

t 08

.70

2.7*

tlft 33

A 06

.55

1 . 2 *

IC*1. 45

* 10

1.29

1 . 2 '.

101. 76

Kftt

103 W

7. M

103 30

1.43

A 13

W. 56

t ID

■ Ml

181.3*

.24

2.24

■ mo. ?3

I. u

A 88

101. M

7.44

103.04

1.31

fl.7\

mi 73

t.40

*.03

IC3.M

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INTERPRETATION OP LIT HIUM MICAS

145

Tablb 7. — Analysis, with data for writing formulas, of siderophyllites and ferrous lithium micas used in interpretation of composition-

Continued

[In order of increasing Li*0 content)

♦ Contains 0.76 BiOj.

NOTES TO TABLE 7

1. New Castle. Ireland (Nock olds and Richey. 1939, p. 39). In grelsen veins cutting

jiplttc veins in granite.

2. Yttgenyam*. Jnpan (Shlbata, 1062b, p. KB, no. 7). In topaz vein tn granite

pegmatite.

3. Ktdsu mine, Nuegl District, Japan (Shlbata, 1962b. p. 162. uo. 6). In greben.

4. Hucbiman. Nuevi District, Japan (Shlbata, 1952b, p. 161, no. 1). In granite

pegmatite.

5. Hitrniman, Nnegi Dbtrtct. Japan (Shlbata, 1962b. p. 161. no. 2). In pegmatite.

6. Hivchinmji, Nwesl Dbtrtct. Japan (Shlbata, 1952b, jo. 161. no. 3). In pegmatite.

7. WHcschbsus, Germany (Stelzner. 1896, o. 391). From granite.

8. Lingvru. Hunan, China (Meng and Ciiang, 1935, p. 57). In pneumatolytlc-

metamorptxved rocks (gTelsen).

9. Volhynla, Russia (Tsygonov, 1UM, p. 3$5. no. 9). From topaz pegmatite.

10. Zlnnwald, Erzezeblrge, Bolaraia (Kunltz. 1924. p. 413).

11. Volhynla, Russia (Buryanova, 1940. p. 532-633). From granite pegmatite.

12. Moran eld mine, Amelia, Va. (Weils. 1937, p. 113).

13. Near Jundal. northwest of 8fto Paulo, Brnzil (Saldanho, 1W6, p. 49). In quartz

veins in gnebs. mlcrngmnitle quartz-porphyry. and gretaeo.

14. I.tngwu, Hunan, China (Meng and Chang, 1935, p. 57). In pneumatoly tic-

meUmorphwwd rook (greben).

15. Aitenburg, Saxony. Germany (Kunltz. 1924. p. 413. no. 7).

16. Yomanota, Nnegl District, Jopan (Shlbata, 1952b, p. 162. no. 5). In pegmatite.

17. Hachiman. Naegt District. Japxn (Shlbata. 1952b. p. 161, no. 4). In pegmatite.

19. Zlnnwald, F.rzeieblrge, Bohemia (Dana, 1892. p. 626. no. 1).

19. Zlnnwald, ErzogehJrge, Bohemia (Kunltz, 1924, p. 413).

20. Zlnnwald, Erzecehlrge. Bohemia (Dana, 1892. p. 626, no. 2).

21. Volhynla. Rusda (Litvin, 1956, p. 120. no. 16). From pegmatite.

22. Elbenstock, Erzegeblrte, Bohemia (stelzner. 1896, p. 391).

23. Volhynla, Russia (Tsrgonov, 1954, p. 3S6. no. 1). From pegmatite.

24. locality not given (Ginzburg and Berhkln, 1953. p. 106).

25. Volhynla. Russia (Litvin. 1956, p. 120. no. 10). Prom pegmatite.

26. Volhynla, Russia (Litvin, 1956, p. 120. no. 0). From tmgmatite.

27. CftttfterltO Creek. Cape York. Alaska (Clarke. 1910, p. 2S7. no. M). W. T.

Schuller, analyst.

2*. Zlnnwald. Ertegeblrge, Bohemia (Winchell, 1942, p. 116, no. 24).

29. Anataboko, Madagascar (Du pore, Wunder, and Sabot, 1910, p. 369). Krona

pegmatite.

30. Volhynla, Russia (Tsyganov, 1954, p. 386. no. 2). From pegmatite.

31. Ltngwu. Hunan, China (Meng and Chang, 1935, p. 56). In pneumatolyUo-

meUmorphneed rock (groi«on>,

32. Sakihnma. Okir.il, Iwnte Pref.. Japan (Shlbata. 1962b, n. 162, no. 17).

33. Cape Ann, Kockpnrt, Moss. (Clarke. p. 358, uo. B). K. B. Riggs, analyst.

34. Cape Ann, Rock port, Mass. (Clarke. 1888. p. 359. no. A). R. B. Riggs, analyst.

35. Cape Ann, Rockport, Moss. (Clarke. 1S56, p. 358, no. C). R. B. Riggs, analyst.

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146

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Tabus 8. — Analyte*, with data Jot writing formula*, of ferrou* lithium mica* not used in interpretation of eompotUion

fin order of Increasing LUO content)

An&ljsh '

Percent

8!Oi

AUOi

no,

FesOj

FeO

MgO

MdO

LtiO

c»o

N'»iO

K,0

n,04-

11,0-

Toul

32.53

17.90

0.88

4.45

30.93

0.13

0.48

0.77

0.3)

0.10

7.19

3.47

1.21

100.34

37.65

16,80

1.10

.32

22.28

2.91

.39

1.21

1.36

3.57

6.54

2.17

0.28

4.28

100.84

Z7.W

24 35

.30

7.W

11.78

.44

.27

1.73

.2)

2.24

10.03

1.2

4.2*

102.27

47.00

25.75

1.40

11.50

.21

.to

1.85

.24

1.77

5.35

4.20

.41

3.09

103.41

35.

20.30

1.00

26.50

.16

.63

2.01

.17

2.30

8.70

2. SO

.28

1.66

102.21

35.90

19.80

1.64

27.80

.30

2.02

1. 74

2.28

5.85

3.00

.30

1.66

102.20

47. 10

24.80

.80

12. 30

.15

2.30

.22

1.00

6.26

4. 47

.23

3.33

103.56

41.78

21.46

.57

.26

15.36

.47

.38

2. 45

2.71

2.64

6.12

1.91

.24

6.95

102.30

45.90

21.21

Tr.

3.78

6.18

.57

4.fO

2. 69

.72

1 29

8 Hd

.44

.38

6.78

•103.47

41.10

25.22

.80

14 10

.05

.74

2.74

.20

1.86

9.80

4.06

.09

2.96

103.71

43.00

24. to

.71

11 . rX)

.05

2.86

1. 18

2.28

9.01

3 tt)

.15

2 .58

101.97

45.24

18.40

.19

1.06

9.95

.28

.63

3.51

1.25

2.78

7.63

2.09

.36

8.32

99.09

46.58

24.10

.69

4.28

.49

1.34

3.56

.68

.84

10.81

7.90

102.77

43.60

25 00

1.36

11.80

.14

.7*

3.70

.42

1.20

7.73

4.04

.44

1.28

101.45

AntUyaU 1

it::::::

14.

Percent

Octahedral pool l Ions occupied by—

O-F,

Adjusted

total

Fc* 1

Mo*>

-0.51

W.84

0.49

0.06

0.03

2.16

0.01

0.03

0.26

— l.bO

90.04

.46

.06

.02

1.44

.34

.02

.38

-1.80

100.47

.86

.02

.42

.72

.05

.02

.51

-1.30

102.11

1.28

.07

.to

.02

.04

.51

-.70

101.51

.53

.09

1.70

.02

.03

-.70

101.50

.50

.00

1.77

.03

.53

-1.40

102. 16

1.24

.04

.71

.01

.to

-2.50

90.80

.SO

.03

.01

.94

.02

.06

.72

-2. 43

101.04

1.00

.00

.15

.36

.06

.29

.73

-1.24

102. 47

1.06

.04

.84

.00

.04

.78

-1.09

100.88

1.11

.04

.69

.00

.81

—2.66

97. 03

.92

.01

.61

.03

.04

1.04

-3.33

99. 44

1.24

....... .

.04

.25

.06

.08

1.00

-.54

100.91

I. os

.07

.69

.01

.04

1.04

Total

3.04
2.72
2.60
2.58
2.99
3.01
2.64
2.87
2.50
2.77
2 . to
2.71
2. to
2.03

Octa-

hedral

charge

+0.46

-.34

+.01

+.07

+.08

-.04

-.32

+.04

Tetra-

hedral

charge

-1.28

-1.08

-1.24

-.79

-1.30

-1.28

::S

-.77

-1.07

-.75

Composite

layer

charge

-0.82

-1.42

-1.23

-.72

-1.23

- 1.20

-.80

-1.36

-1.17

-1.19

-1.27

-1.30

-1.16

Inter layer cations

Charge Positions

+0.82
+1.41
+1.28
+.74
+1.22
+1.19
+.80
+1.37
+1.18
+1.18
+ 1.31
+ 1.31
+1.17
+.M

0.80

1.30

1.26

.72

1.19

1.05

.78

1.16

1.12

1.13

1.22

1.21

1.12

1 Bee descriptions below for origin of samplers and source of analyses.
* Contains 2.04 percent (Rb,C*)i0.

NOTES TO TABLE 8

1. VolhynU, Russia (Buryanova. 1910. p. 522-523).

2. VolhynU, Russia (Litvin, 1956, p. 120. no. 6). From pegmatite.

3. Quyw, Saxony, Germany (Dana, 1892, n. 627, no. 2).

4. VolhynU, Russia (Tsyganov, 19M, p. 3#6, no. 3). From pegmatite.

5. VolhynU, Russia (Tsyganov, 1954, p. 386, no. 10). From pegmatite.

6. VolhynU, Russia (Tsyganov, 1954. p. 386, no. 11). From pegmatite.

7. VolhynU, Russia (Tsyganov, 1954, p. 386, no. 6). From pegmatite.

8. VolhynU, RussU (Litvin. 1950, p. 120, no. 7). From pegmatite.

9. Mlnagl, Okayama Pref., Japan (Ukul, NUblmura, and Hashlmoto, 1956, p. 32

no. 2).

10. Volhynla, Ku»U (Tsyganov, 1054, p. 386, no. 8). From pegmatite.

11. VolhynU, Russia (Tsyganov, 1954, p. 386, no. 4). From pegmatite.

12. VolhynU, RuksU (Litvin. 1956, p. 120, no. 14). From pegmatite.

13. New Ross, Nova Scot la (Walker tuid Panama, 1924, p. 49). From pegmatite.

14. Volhynla. Russia (Tsyganov, 1954. p 386, no. 6). From pegmatite.

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INDEX

Alumlnlan lepldomclanw

lithium mlaw

Aluminum lithium micas ............

and ferrous lithium micas, relation...

Anionic composition of micas

Annite ...

Fax*

134131, 132. 134. 138

124. 129

118. 119. 117. 120. 121. 122. 124. 128. 133, 140

137

114

131

Borggren, Thelma...... 125

Berkhln, 3. L See Olnxburg, A. L and Berkhln, 8. L

Blottto 113, 114 128, 140

Blotlte-lepldolito serins 127. 128

Clarke. F. W 138

Compositional changes shown by the analyses 117. IS

relations In sldcrophyllltos and frmxu lithium mints 130

Compositions, previous Interpretations 127

Cooke, J. P. Jr 127. 136. 140

CryophyUlte 127.123, 122.139, 137, 140

Cryopbylllte*zlnnwaldlto relation.... 137

Dana. E.S 127. IS. 138

Dloctabedral mica 112

potassium miens ...... ........ 115. IS

Fo**.LI replacement ratios 131

Ferrlan sldnophyllltcs 130. 134

FerTOan lepldolltes 135. 139, 140

Ferrous lithium micas 116. lift. 127. 128. IS. 130. 131. 132, 135

slderophylllte*, and aluinlnlan lepklomctancs, relation IS. 140

Formulas, calculation of................ ...................... ....... 115

Foster, M.D 119. 117. IS. 130, 181

(llnrbcirc, A.J. and Berkhln, 8. 1...... 117. IS

llalllmond, A. F IS. 136. 139

Hendricks. S. B. and Jefferson, M. E 117.124. 125. 127, 139, 140

HeptapbylllUe micas 119. 127. IS. 135

Hey, M.H 128. IS, 135. 135

Interlayer cations 118

Jefferson, M.E. See Hendricks, 8. B., and Jefferson, M. E.

Sunlit, Wilhelm 127.135.136

L« 1313,81) - 127.128

Leptdollto series 128

structure 117, 124

Lepldolltes, Interpretation of composition 110, 128,196

Lepldolltr-muscovltc association — 117

Lepldolite-pcotolltblonltc series 127.128

Lcpldomclancs. 115. 135

Levinson, A .A 117.124.125.127. 140

Ltth lan muscovites 116. 124. 125. 128

Interpretation of composition... 125. IS

Llthian sfdcropbylUtes 135. 140

Fax*

Lithium and occupied octahedral sites relation 122

and octahedral Al. relation between 119. 138

LI and SI relation 131

LI and total Al relation 121

Lithium and trtvalent octahedral cations, relation IS!

LI, effect on formula calculation US

Lithium micas 118

Lithium micas, unusual 139

Lithium muscovite 119. 119

LHoctahedral Al) replacement raUo 117. IS. 121. 122. 125. 137, 138. 140

Lithium, relation to other constituents In calculated formulas 119

U and Fe*» relation 130

LI -R« and SI relation 121

LliO and F relation ..... IS

I.IjO content, octahedral occupancy, and structure 122

Magnesium-replacement system 118.129

Marshall. C. E 118

Miser, H. D 139

Mixed structure 124. 129

MnscovtU 114. 117. 119. 123, 121. 128. 129. 127. 138. 139. 140

Muscovite structure 114124

Octahedral group 115

Octahedral replacement of blvalcml by trlvalent cations 115

Octahedral replacement of trlvalent by bivalent cations 115

Oetapbylllc micas 119, 127. 129. 135

Paudllthlonlte 114119

Phonglte. 128

Phlogoplte 118.139

Phlogoplto-taenlolltc series 139

Polyllthtonlte 116. 119. 120. 126. 127. 132. 138. 139. 140

Protoll Ihtonlte 114 127. 129. 132 135. 138. 139. 140

Riggs, R.B 136

8chalier, W. T 124

Slderophylllte 129. 130. 131. 132. 133. 134.137.138,139. 140

Stderopbyllite-lrpUlolllc Isoiuorpbous series 132

Slderophylllte* and lepldomelanes 118.134

Stevens, R. E 118.117.118. 124. 127, 139

Structure of aluminum lithium micas 124

polymorphic variations In... 125

transition In 124

Tetrahedral group

121

TrlllthlonUo

115.119

TrUiUdc-tcUmtUldc antes

130. 131.132

Wlnchcll, A. N

110. 117, 12-f, 177, 129. 135.136

Zlnnwaldlte

127 129 132.135 1». 139 140

147

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Zones and Zonal
Variations in
Welded Ash Flows

By ROBERT L. SMITH

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 3 54-F

A concept of zonation in ash flows
based on degree of welding and
type of crystallization

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.

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CONTENTS

Pane

Abstract 149

Introduction 149

Acknowledgments 150

Eruption and emplacement 150

Welding 151

Crystallization 151

The zones 153

Zone of no welding 154

The zones — Continued Pass

Zone of partial welding 154

Zone of dense welding 154

Zones of crystallization 155

Cooling unit 157

Composite sheet 158

Influence of buried topography 158

References cited 158

ILLUSTRATIONS

Plate 20.
21 .

Diagrams showing zones of some ash-flow cooling units In pocket

Zones of no welding, partial welding, and dense welding, and their approximate crystalline equivalents Facing page 152

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

ZONES AND ZONAL VARIATIONS IN WELDED ASH FLOWS

By Robert L. Smith

ABSTRACT

Welded tuffs are recognized an special parts of ash flows,
other pyroclastic flows, or, more rarely, air-fall deposits. Ash
flows may he emplaced at any temperature below a maximum
eruption temperature. Those emplaced above a minimum
welding temperature may show any and all degrees of welding
and crystallization.

Three basic zones are recognized, the zones of no t adding,
partial icelding, and dense tedding. In sheets where the zone
of dense welding occurs, the zones of no welding and partial
welding will have upper and lower counterparts.

Cooling of welded ash flows may result In sheets that range
from completely glassy (except for phenocrysts and Inclusions)
to mostly crystalline.

Crystallization superimposed on the zonal patterns produced
by welding results In another set of zones that la controlled In
part by degree of welding.

Three principal types of crystallization that take place dur-
ing the cooling history are recognized. These in order of fre-
quency of occurrence, are devitrification, vapor-phase crystal-
lization, and granophyric crystallization. The zone of devitri-
fication Is common to most crystallized welded tuffs and fre-
quently occupies most of the zones of dense welding and partial
welding. The zone of vapor-phase crystallization, where pres-
ent, occupies the porous parts of the welded tuff sheets and
reaches Its maximum development In the upper zone of partial
welding where It overlaps the zone of devitrification. The
zone of granophyric crystallization Is probably confined to cool-
ing units several hundreds of feet thick where It will divide
the devitrlfled zone Into upper and lower parts. Fumarolle
alteration may be found In the upper zone of no welding.

Single ash flows may cool with the formation of a basic
pattern of zones. This pattern Is Illustrated and described
both for those sheets which remain glassy and for those In
which crystallization has occurred. These flows are called
simple cooling units.

Successive ash flows, emplaced quickly enough to bridge the
cooling gap between flows, will form a stack of flows that may
also cool to form the zonal pattern of a simple cooling unit.
The gaps or hiatuses, here called partings, may contain or
consist of lump pumice layers, flow surfaces reworked by wind
or water, alrfall pyroclastic material, other deposits, or minor
erosional unconformities.

Compound cooling units consist of multiple flow units with
or without visible partings and which show zonal patterns
that depart from the patterns of the simple cooling units.

649220 — eo

Horizontal separation of compound cooling units Into separate
cooling units suggests the existence of a hypothetical unit, the
composite sheet, which could have tlme-stratlgraphlc signifi-
cance.

Buried topography can have a profound Influence on the
zonatlon of certain ash-flow cooling units. Very hot ones, be-
cause of their high compactabllity potential, will show lees
zonal change than colder ones, although they will show greater
surface expression of the burled topography. Abrupt changes
In relief, especially If the burled topographic high rises to the
top of the zone of dense welding, can cause horizontal changes,
in a short distance, that may be difficult to Interpret.

INTRODUCTION

In this report, welded tuffs are considered to be spe-
cial parts of ash flows, other pyroclastic flows, or more
rarely, air-fall deposits (not to be confused with fused
tuffs, p. 155) . Most students of welded tuffs have rec-
ognized vertical variations of texture, specific gravity,
color, mineralogy, and other properties within the de-
posits. Horizontal variations are rarely emphasized
because complete ash-flow sheets have not been mapped,
particularly in detail. Mapping of complete sheets has
not been done because of the generally large areal ex-
tent of the sheets, they may be of only casual interest
to the mapping problem, or because erosion, and cover
by younger rocks, limits their area of exposure.

The uniform and unsorted character of ash-flow de-
posits has been cited as a criterion for their recogni-
tion. Although this is generally true, the complex
emplacement and cooling history of many such de-
posits may produce various textural and mineralogical
facies that bear little or no resemblance to the original
materials of the ash flows. These variations are zonal
and normally show a consistent pattern of transitions
both vertically and horizontally in uniform ash flows
which have had an unimpeded cooling history. Once
this zonal pattern is clearly understood for simple cool-
ing units, progress can be made in interpreting aber-
rant patterns in more complex deposits.

140

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150

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The purpose of this report is to describe the zones
and the simple zonal patterns by means of 4 simplified
diagrams (pi. 20 A-D) and a brief text. The dia-
grams are not intended to represent specific welded
ash flows but are simply hypothetical models. They
were constructed to illustrate, in part, the writer’s
concept of simple ash-flow cooling units. The scales
used give an order-of-m&gnitude relation among the
different zones that is probably realistic for some nat-
ural sheets. The most difficult characteristics to gen-
eralize are the horizontal changes, because a cooling
unit may range from less than a mile to many tens of
miles in length, or from less than a square mile to
hundreds and perhaps thousands of square miles in
area. The true nature of the distal ends is generally
problematical. They are rarely preserved or recog-
nized in prehistoric sheets and there appears to lx? a
wide variation in historic “nu6e ardente” deposits,
from “snub noses” to thin tapered ends often measur-
able in inches.

The diagrams were constructed based on the assump-
tion that some cooling took place in the direction of
thinning. Although this is probably a common condi-
tion it. is by no means necessarily true for all flows.
Some widespread ash-flow cooling units show only
slight effect of cooling or thinning over tens of miles
whereas others show marked effects in only a few miles.
The direction of thinning may be related to the surface
underlying the flow or it may reflect a change away
from the source area. These facts, among others, indi-
cate the need for a critical examination of accepted
concepts on the mechanics of eruption and emplace-
ment of ash flows.

The use of welded tuffs for correlation purposes pre-
sents many pitfalls to the geologist, but with careful
work a high degree of success should lie achieved. The
potential importance of these rocks as stratigraphic
marker bods cannot be overemphasized, considering
their possible long-distance continuity in terrane where
lensing and facies changes, in sedimentary' and other
volcanic deposits, are common.

The presentation of hypothetical diagrams without,
documentation leaves much to be desired. Also much
of this report, may seem academic concerning very
young and undeformed welded ash flows. However,
this study should have practical merit where applied
to mapping and interpreting problems in highly de-
formed areas. It should also lx? useful in regions
where ash-flow sheets from different sources overlap,
and in the vicinity of some ore deposits where the geol-
ogist must locate relative spatial position within a rock
body. In the vicinity of most ore deposits, alteration
of different types will further complicate matters, but

this difficulty may be overcome if the geologist has a
clear understanding of the normal characteristics of
the unaltered rocks. The zonal patterns will be ex-
tremely important for detailed geochemical studies.

ACKNOWLEDGMENTS

The writer is indebted to Clarence S. Ross with
whom he has studied welded tuffs for many years and
with whom he has written a more comprehensive re-
port (Ross and Smith, 1960). Much of the material
in the present report is an outgrowth of this earlier
study, although the writer is solely responsible for the
organization of the data and theory as presented here.
The writer is especially indebted to Roy A. Bailey,
also a close working companion of many' years, who
has been a most helpful critic. Of the many other
Geological Survey colleagues who have aided the writ-
er’s studies special thanks are due C. A. Anderson and
Harry W. Smedes for their constructive criticisms.

ERUPTION AND EMPLACEMENT

Much could be written about the eruption of pyro-
clastic materials that are emplaced as hot sheetlike
bodies and whose slow cooling may result in deposits
that show striking physical and chemical differences
from the initially erupted material. However, the
main purpose of this report is to discuss the more obvi-
ous characteristics of the deposits after they have
cooled. It is well recognized that these deposits were,
for the most part, emplaced as hot avalanchelike
masses or particulate flows, many if not all of which
contained hot gas and many of which were autoexplo-
sive. The evidence for flowage as the principal mech-
anism for emplacement of these deposits has been cited
by many authors; the most fundamental papers are
those by Fenner (1923), Marshall (1935), and Gilbert
(1938). In the present report, the basic unit of most
of these deposits is referred to as an ash flow.

Ash flows can probably be emplaced at any tempera-
ture below a maximum eruption temperature. How-
ever, there will he a temperature of emplacement below
which no visible physical or chemical changes will take
place during cooling. This temperature may be re-
ferred to as the minimum welding temperature and
will vary from place to place with changes in the vari-
ables that control the lower limit of the softening
range of the glass.

Non welded ash flows are important, but those em-
placed at temperatures above their minimum welding
temperatures are of greater interest.

A single ash flow may be the only unit of cooling, or
two or more ash flows, with or without intercalated
air-fall beds or other partings, may combine to form

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ZONES IN WELDED ASH FLOWS

151

the cooling unit. A deposit that can be shown to be a
cooling unit in one place, may by division horizontally,
become two or more cooling units, separated by chill
zones, air-fall pyroclastic rocks, sedimentary deposits,
erosional unconformities, or lava flows. The writer
will refer to this complex rock body as the composite
sheet. The complexities inherent in such a scheme are
infinite and the geologic implications will be obvious.

WELDING

The welding process must begin immediately after
emplacement if the ash flow or any part of it, comes
to rest above its minimum welding temperature. Weld-
ing continues until it is complete or until the process
is stopped by cooling or crystallization of the glass.

In the present report welding is briefly defined as
that process which promotes the union or cohesion of
glassy fragments. The degree of welding may range
from incipient stages marked by the sticking together
or cohesion of glassy fragments at their points of con-
tact and within the softening range of the glass to
complete welding marked by the cohesion of the sur-
faces of glassy fragments accompanied by their defor-
mation and the elimination of pore space, and perhaps
ultimate homogenization of the glass.

Incipient welding may be recognized in some very
young and fresh glassy tuffs by brittle rather than
crumbly fracture, although the rock is very porous.

. However, this criterion is not entirely dependable be-
cause other types of induration may cause the rock
to break in a similar manner.

Where the distinction between nonwelded and in-
cipient!}' welded tuff is necessary, the boundary should
be placed at, or close to, that, point where deformation
of glassy fragments becomes visible. Deformation of
puiniceous fragments and shards is the only positive
criterion of welding in the tuffs which have crystal-
lized, particularly in older rocks.

Incipient welding presumably takes place in most
welded tuffs before the deformation of glass fragments
becomes visible, because the deformation accompanying
welding is related primarily to lithostatic load pres-
sure, especially at. the lower temperatures. In practice
the transition between visible deformation and obvi-
ously nonwelded tuff can be located in most tuffs
within a few feet or at most a few tens of feet..

Even the sillars (Fenner, 1948, p. 883), those col-
unmar-jointed, largely crystalline, but very porous
tuffs, which are believed to be indurated by crystalliza-
tion rather than by welding (Fenner, 1948, p. 883;
Jenks and Goldich, 1956, p. 157), were probably incip-
iently welded before they crystallized. Specimens of

salmon and white sillars kindly given to C. S. Koss
and the writer by Fenner, are interpreted by the writer
to be incipiently welded. Some of the specimens of
salmon sillar show practically no crystallization but
are firmly coherent. They show slight deformation of
shards in thin sections and incipient compaction folia-
tion in hand specimens. The white sillar, on the other
hand, is completely crystalline and could represent
salmon sillar that has crystallized in the vapor-phase
zone of a cooling unit.

The sillar-type tuffs were probably emplaced at
temperatures as high as that of many densely welded
tuffs but the load pressure within the deposits was in-
sufficient to cause obvious visible deformation of the
glass before crystallization (white sillar) or cooling
Inflow the minimum welding temperature (salmon sil-
lar) began. If these tuffs could be traced horizon-
tally into thicker cooling units, the degree of welding
would increase greatly.

The transition from incipient to complete welding is
one of progressive loss of pore space accompanied by
an increase in deformation of the shards and pumice-
ons fragments (pi. 21 A-F). The progressive flatten-
ing of shards and pumice, produces the streaky foliate
structure long known as eutaxitic structure, which can
!)c seen in outcrop, hand specimen, and under the
microscope.

In most welded tuffs complete welding is probably
achieved by simple load deformation, without stretch-
ing of particles, other than that necessary for local
accommodation to available space. Crinkling or crenu-
lation around crystal or rock fragments is common,
and in many pumice-rich or inclusion-rich tuffs wavy
eutaxitic foliation is normal.

Flattened pumiceous fragments, depending on their
primary shape, arc normally disclike in the plane of
flattening. However, in some tuffs, usually in the
lower part of the cooling unit, the fragments are elon-
gate rather than disclike and show a preferred orienta-
tion. In most such examples probably some mass flow-
age has taken place in the sheet during welding. In
welded tuffs of this kind observed by the writer, the
stretching could have been accomplished by mass move-
ment of from less than a few inches to a maximum of
a few feet. Such mass flowage might be related to
buried topography, earth movements during welding,
or other factors, and more rarely, might be of greater
magnitude.

CRYSTALLIZATION

Crystallization of the glass takes place in many ash
flows subsequent to, or perhaps in part synchronous

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

with, the welding process. Physically and (or) chemi-
cally different environments within the cooling unit
may give rise to different types of crystallization.
These may, depending on the degree of their develop-
ment, be recognized as distinct, although overlapping,
entities, and togethor with the degree of welding, can
be potential guides to relative position within a de-
posit.

Three principal categories of crystallization which
may take place during cooling are recognized by the
writer. In order of frequency of occurrence, these are
devitrification, vapor-phase crystallization, and grano-
phyric crystallization. Throughout the report the term
“cooling-history crystallization” refers to these three
types, and to fumarolic alteration unless otherwise spe-
cified. The principal categories of cooling-history
crystallization may be defined as follows:

Devitrification.— Crystallization of glass to form
spherulitic and axiolitic intergrowths and aggregates,
chiefly of cristobalite and feldspar. This crystalliza-
tion is confined within glass fragments or massive
glass. It is common to all crystallized silicic welded
tuffs.

Vapor-phase crystallization. — The growth of crys-
tals, from a vapor phase, in pore spaces. Vapor-phase
crystallization is, in general, a coarser grained crystal-
lization than devitrification, and is commonly manifest
in the porous upper parts of welded ash flows where
it is contemporary with, or follows, devitrification. In
rhyolitic ash flows the predominant vapor-phase min-
erals are alkalic feldspar, tridymite, and cristobalite.

Granophyric crystallization. — In silicic welded tuffs
granophyric crystallization is characterized by ground-
mass quartz intergrown with, or as blebs associated
with, alkalic feldspar and minor accessory minerals.
The aggregate shows granophyric or micrographic tex-
tures similar to those shown by many slowly cooled
rhyolitic flows, domes, and shallow intrusive rocks.

Granophyric crystallization (quartz) has never been
seen by the writer in fresh unaltered welded tuffs that
were less than about 600 feet thick. However, many
older deposits and ultimately all deposits will probably
contain quartz as the groundmass silica mineral,
through conversion of critobalite and tridymite.

A fourth category of cooling-history crystallization
or, probably more precisely, alteration, should be rec-

EXTI/A NATION O t PLATE 31

ZONES OF NO WELDING, PARTIAL WELDING, AND DENSE WELDING, AND THEIR APPROXIMATE

CRYSTALLINE EQUIVALENTS

Specimens A-F allow transition from zone of no welding to zone of dense welding. Specimens G-L show approximate crystalline
equivalents In zones of partial welding and dense welding. A-B, from Battleship Rock, Jemez Springs quadrangle; G-I, from the
Bandelier rhyolite tuff (Smith, 1938), Jemez Mountains, N. Mex.

A. Zone of no welding. Pumice blocks and lapilli in an uncon-

solidated ashy matrix. Some accidental rock fragments.

B. Zone of partial welding (upper part of upper zone). Shows

incipient compaction foliation. Fracture takes place
through, rather than around pumice fragments. Matrix
ash more gray tlian in A.

C. Zone of partial welding (upper zone). Compaction foliation

well developed, pumice fragments darker with less pore
space and more vitreous luster than in B. By contrast,
the ashy matrix still has a dull luster and hackly fracture.

D. Zone of partial welding (lower part of upper zone). Col-

lapsed pumice lenticles and matrix ash have vitreous luster
and conchoidal fracture although pore space is still about
20 percent.

B. Zone of partial welding (near transition to zone of dense
welding). Collapsed pumice lenticles obsidianlike without
pores although traces of former vesicles can still be seen
in thin section.

F. Zone of dense welding. Denso black obsidianliku glass of
virtually zero porosity. Collapsed pumice fragments only
faintly visiblu in hand specimen. Their boundaries are
visible in thin section but former vesicular structures have
been partly to completely homogenized by welding. From
km 153, Taxco Highway, Central Mexico. Collected by
Carl Fries, Jr.

0. Vapor-phase zono (upper part of upper zone of partial
welding). Slight compaction foliation; completely dc vitri-
fied. Pumice fragments crystallized into drusy growths
of tridymite and alkalic feldspar and some cristobalite.

Tho pumicc-tube structure is well preserved. Approxi-
mate crystalline equivalent to B. Very similar, except
for fragment size, to white sillar described by Fenner.

II. Vapor-phase zone (upper zone of partial welding). Com-
paction foliation well developed. Puraicc-tubc structure
not as well preserved in this plane, but very obvious in
the plane of flattening. Approximate crystalline equiva-
lent to C.

I. Dcvitrificd zone (zone of dense welding). Some collapsed

pumice fragments visible. In thin section this specimen
shows coarse axiolitic devitrification.

J. De vitrified zone near base (zone of dense welding). Fine-

grained devitrification of a dense black glass. Only faint
traces of original pyroclastic character preserved in hand
specimen. Perfect preservation of shards and flattened
pumice fragments in thin section. Crystalline equivalent
to F. Matahina ash flow, Rangitaiki Gorge, North Island,
New Zealand. Collected by R. A. Bailey.

K. Specimen showing the effect of gas trapped during welding.

The rock belongs in the zone of dense welding but the
collnpscd pumice fragments are miarolitic and coarsely
crystalline. From the lower part of Enlows’ (1955) mem-
ber 6, Rhyolite Canyon formation, Bonita Canyon, Chiri-
cahua National Monument, Ariz.

L. Lithophysal cavities in the devitrified zone of dense welding.

This rock is composed of fine-grained pyroclastic materials
which probably caused lithophysae to form instead of
miarolitic cavities in pumice fragments. From the Ammon
quadrangle, Idaho.

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ZONES IN WELDED ASH FLOWS

153

ognizable in many deposits. This little-studied and
generally unrecognized (in older deposits) process is
fumarolic alteration. Some geologists may argue that
this process is not basically different from vapor-phase
crystallization, but the products are notably different
and, generally belong to lower temperature and pres-
sure environments.

Devitrification of the glass after initial cooling, and
other forms of low-grade alteration need much discus-
sion, but these should be considered in well-documented
papers. Correct interpretation of cooling-history proc-
esses is obstructed by post-cooling-history, hydration,
devitrification or other alteration of glass, oxidation
of iron, and conversion of tridymite and cristobalite
to opal, chalcedony, or quartz, and related processes.
Some of these processes take place during as well as
after cooling, and the knowledge necessary to always
distinguish between the two has not yet been acquired.
In Pleistocene and Recent rocks the problems are mi-
nor or nonexistent, but in some Pliocene and in most
Miocene and older formations many physical and
chemical properties of the rocks seem to have been
affected by processes that occurred after cooling. Depth
of burial and ground-water conditions are extremely
important factors. Many geologists consider these al-
tered rocks to be fresh and unaltered.

These alteration effects are often of regional extent
and can best be interpreted as low-grade metamorphic
reactions.

THE ZONES

All ash flows in which welding or crystallization
have taken place show zonal variations in texture,
color, or other features. These variations are depend-
ent upon such factors as temperature, thickness of the
deposit, composition of the ash, amount and composi-
tion of volatile constituents, and the ratio of pumice
fragments to shards.

Any system that includes several variables where
one variable can change the entire appearance of a rock
body, or any part of it, is a very flexible system, and
must be treated as such. The chance that two or more
welded ash flows will show no differences as a whole
is extremely slight. On the other hand, the close simi-
larities that commonly exist between some welded ash
flows may be confusing and it may be impossible to
distinguish between their equivalent zonal facies. Dif-
ferentiation may then be dependent upon detailed pet-
rographic studies of phenocrystic minerals coupled
with careful field study.

The zones shown in plate 20 are those which can be
easily recognized or inferred in the field. Recognition
of minor zones depends on the microscopic study ; they
are briefly mentioned in the following discussions of

the individual major zones. All zone boundaries are
transitional, some more abruptly than others. In gen-
eral the boundaries of the basal zones are more sharply
defined than those of the upper zones.

The ordered sequence of overlapping zones is best
visualized by examining first the zones formed during
the welding process without crystallization upon cool-
ing. If welding proceeds to completion in any part of
an ash flow, three distinct zones will be formed. These
are the zone of no welding , the zone of partial welding ,
and the zone of dense welding (pi. 20 AJ3). The
upper zones of no welding and partial welding will be
separated from the lower zones of no welding and par-
tial welding by the zone of dense welding. Where
sufficient lateral thinning of the ash flow occurs, such
as the normal distal ends and margins, points will be
reached where the upper and lower zones of partial
welding will merge and grade into the nonwelded
mantle of the deposit.

This simple pattern of zones is illustrated in plate
20/1 and B. Plate 20Z? shows the zonal relations in an
extremely hot and moderately thin ash flow whereas
plate 20/1 shows the zonal relations in a thicker ash
flow emplaced at much lower temperature. Plate 202?
also shows an additional zone which represents an
early stage of crystallization. This additional zone in
no way affects the comparison of the other zones illus-
trated in plate 20 A and B. An ash flow emplaced at a
temperature too low for welding is not shown, but is
represented by the nonwelded mantle (pi. 20.4). All
transitions between this low-temperature extreme and
the hot, densely welded type shown in plate 20 B can
occur. However, as temperature and thickness are
increased together, a point will be reached where crys-
tallization begins; thus the type of tuff illustrated in
plate 20 B can never reach great thickness and remain
glassy throughout during cooling.

The glass of densely welded tuff that is of the order
of thickness shown in plate 20/1 and B will probably
be charged with spherulites or lithophysae or both,
although these may vary in number and character with
the initial gas content.

Crystallization usually follows, but may in part, ac-
company the welding process. This crystallization
may occur in a narrow zone confined to the deep inte-
rior of the cooling unit or as a broad zone which may
overlap, horizontally at least, all other zones formed
during welding. All transitions between the two ex-
tremes may occur.

The character of crystallization is strongly influ-
enced by the degree of welding of that part of the tuff
upon which it is superimposed, the rate of cooling of
the ash flow, and the amount and composition of vola-

154

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

tile materials that it contains. Differences in character
of crystallization, then, add another set of zones con-
trolled in part by the zones already formed during
welding, and in part by other factors.

ZONE OF NO WELDING

The zone of no welding is that part of an ash flow
in which no welding has taken place (pi. 21/1). This
zone may comprise the entire ash flow or only a small
part. Most single ash-flow cooling units have a non-
welded top and bottom (pi. 20/1), although in some of
the very hot flows the nonwelded bottom may not be
present under the entire sheet (pi. 20# and C). In
these very hot ash flows densely or partly welded tuff
may extend to the base of the unit, especially near the
source area.

The nonwelded zone will probably contain some in-
cipiently welded tuff, especially in the crystalline units,
because as mentioned on page 151, the only practical
way to locate the zone boundary is by megascopic de-
tection of deformation or compaction foliation. Incip-
ient welding occurs at some point before this.

The nonwelded zone is commonly the least spectacu-
lar part of a welded ash flow, but is probably the most
important, zone because it is tho only one that shows
the original character of tho erupted materials. Its
preservation is necessary to such measurements as ini-
tial density and porosity, size analyses, and to the
nature of the primary glass. For the most accurato
characterization of the magma, chemical analyses
should be made of pumice from this zone (pi. 21.4),
providing that the rocks are fresh and the pumice is
not foreign material. Most middle to early Tertiary
and apparently all known pre-Cretaceous ash-flow tuffs
show some alteration in this zone beyond simple hydra-
tion of the glass and are not too helpful in understand-
ing the chemistry of the primary magma.

ZONE OF PARTIAL WELDING

The zone, of ■partial welding includes all material
ranging from that which shows incipient welding to
that which has lost virtually all its pore space (pi.
21 B-E). This zone shows a greater diversity of tex-
tures than any of the other zones because of the wide
range in porosity and degree of deformation of its
glassy parts. The boundary between the zones of par-
tial and dense welding is discussed below.

Further subdivision of the zone might have practical
application in some welded ash flows. For example,
a measure of tho degree of collapse of pumice frag-
ments can be an important factor in determining the
relative vertical position of material in the sheet.

In some cooling units the upper zone of partial weld-
ing may extend horizontally for many miles without
much apparent change in thickness as long as it is
underlain by a zone of dense welding.

The zone of partial welding is best developed in
colder ash flows (pi. 20 A) and is poorly developed in
very hot ash flows (pi. 20#). The thickness of this
zone is therefore, in a general way, an index of the
emplacement temperature of the ash flows.

ZONE OF DENSE WELDING

Ideally the zone of deme welding should be defined
ns that, zone in which complete coalescence of the glassy
fragments has resulted in the elimination of all pore
space. A dense black glass or vitrophyre is the normal
product of this process (pi. 21 F). Actually it will be
a rare welded tuff that is completely pore free, exclu-
sive of the vitrophyre zone in some sheets, because of
processes other than welding that help determine the
final character of the rock. Entrapped or exsolved
gas, for example, causing the formation of lithophysal
(pi. 21Z) or other types of cavities, may inhibit com-
plete loss of pore space in this zone during welding.
However, in the groundmass surrounding these porous
areas, complete welding of the shards will show that
the rock is in the zone of dense welding. The bound-
ary between the zone of dense welding and the upper
zone of partial welding marks a plane below which the
rock is pore free, or potentially pore free were it not
for entrapped gas, and above which the rock would
be porous, with or without gas entrapment. Crystal-
lization of a pore-free glass may result in a slightly
porous rock. All these factors must lie considered in
distinguishing the zone of dense welding from the zone
of partial welding.

If the welded tuff remains glassy upon cooling, all
the zones and zonal transitions are generally well de-
fined and simple, although in the simple cooling units
the transitions above the zone of dense welding are less
sharply defined than those below. However, when
crystallization takes place, the upper transitions may
become obscure, and the exact, location of the zone
boundaries in some sheets will be largely subjective,
particularly in crystal-rich quartz latites and rhyo-
dacites.

The transition from partial to dense welding in
glassy welded tuffs is best shown by changes in the
pumice fragments present in most ash flows. In fresh
rocks and those that have had a simple cooling history,
the pumiccous fragments and blocks change by de-
creasing porosity and a general darkening of color
until they become black and obsidianlike (pi. 21A-F ) .

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ZONES IN WELDED ASH FLOWS

155

The darkening of the puraiceous fragments precedes
the darkening of the shard}’ matrix. For field pur-
poses the end stage of the welding process is a dense
black glass in which the pumiceous fragments and the
matrix are megascopically indistinguishable.

Complete welding is not achieved until the pumice-
ous fragments, shards, and glass dust are homoge-
nized; all grain boundaries disappear and, exclusive
of crystals and inclusions, a completely homogenous
glass is formed. This zone of homogenization can only
be proven by microscopic study in conjunction with
field study, and will be found only rarely, probably for
the following reasons: (a) In ash flows initially thin
enough or cold enough to remain uncrystallized after
cooling, temperatures and pressures high enough to
cause homogenization of the glass particles are rare;
(b) in thick cooling units where a zone of complete
homogenization might occur, this zone will likely crys-
tallize on cooling and may be indistinguishable from
nonhomogenized welded tuff whose vitroclastic struc-
ture has been obliterated by crystallization. Partial
homogenization of tube structures in pumice frag-
ments is common in some glassy welded tuffs but com-
plete homogenization is rare. Tube structures refer
to tubular vesicles which are more common than spher-
ical vesicles in pumice from tuffs of silicic composition.
These tubes are sometimes so fine that they present a
fibrous appearance and cause the pumice to have a
silky luster. The writer has never seen complete ob-
literation of shard boundaries in glass}’ rocks but it
will no doubt be found, and it is for this reason that
the point of homogenization is emphasized.

The vitrophyre zone generally shows a transition
downward through a partly welded zone to a non-
welded base which may range from almost zero to
many feet in thickness. However, some flows were em-
placed at such high temperature that, the vitrophyre
zone extends to the base of the cooling unit and, in
some vertical sections, may extend below the base of
the unit as a fused zone in underlying glassy pyro-
clastic deposits (pi. 20/)). This fused selvage will
probably never be more than a few feet thick. If the
underlying material is bedded ash, the bedding may
still be preserved in the vitrophyre. An excellent
example of this basal fusion has been described by
Boyd. 1

The vitrophyre zone (pi. 20(7 and D) is often the
most useful part of a cooling unit for mapping pur-
poses, especially in complexly faulted rocks, as it pro-
vides a useful marker unit.

1 Boyd. F. B.. 1937. Geology of the Yellowstone rhyolite plateau :
Ph. D. thesle, Harvard Unlv., 134 p.

ZONES OF CRYSTALLIZATION

A large proportion of welded ash flows have crys-
tallized to some degree upon cooling. Crystallization
may lie incipient or intensely pervasive. Incipient
crystallization may lie marked by growths of minute
spherulites in the zone of dense welding, or by the
presence of vapor-phase or fumarolic minerals in scat-
tered fine-grained growths in the upper porous zones.
Crystallization may also be so extensive throughout the
cooling unit that only a very thin chilled base, top, and
distal end of the unit will remain glassy after cooling.
Crystallization in most welded ash flows will fall some-
where between the two extremes (pi. 20C) .

Devitrification is the most common crystallization
process and in most cooling units the products of de-
vitrification will be present throughout the entire crys-
talline zone. However, in some porous rocks these
products will be subordinate to those of vapor-phase
crystallization because of intense vapor-phase activity.

In rhyolitic tuffs, devitrification consists of the si-
multaneous crystallization of cristobnlite and alkalic
feldspar to form submicroscopic sphcrulitic and axio-
litic intergrowths of these minerals plus minor acces-
sory minerals. This devitrification process is confined
within shards or glass masses, whereas crystallization
by growth of crystals into pore spaces is a different
process related to the movement of vapors and transfer
of material. Without pore space, vapor-phase crystal-
lization cannot take place. Thus in densely welded
tuff that has not entrapped large quantities of gas, de-
vitrification is the dominant and commonly the only
process of crystallization. For this reason the writer
refers to the crystallized part of the zone of dense
welding as the devitrified zone (pi. 21/ and J). The
crystalline porous zone is referred to as the vapor-
phase zone (pi. 21(7 and /7), if it contains crystal
growths in the pore spaces, or if it is probable that
it had crystal growths in the pore spaces.

The ideal boundary between that part of the zone
of devitrification that contains the vapor-phase zone,
and that part in which the vapor phase does not occur
is the boundary between the zone of dense welding and
the upper zone of partial welding (pi. 20(7). The
abrupt appearance of the lower boundary of the vapor-
phase zone will depend on the sharpness of transition
between the glassy zones before crystallization. In
some tuffs this transition may take place within a few
feet, whereas in others it may be so broad that it may
be difficult to detect at all.

Some of the features that may mark this transition
are: (a) The upward appearance of vapor-phase min-
erals; (b) a visible upward increase in porosity; (c)

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

a downward change in color or shading of color from
light to dark; (d) a downward change from coarse to
fine joint spacing; and (e) the zone of dense welding
is usually a better cliff former in crystalline tuffs.

Curves derived from density or porosity measure-
ments of vertical sections of simple cooling units may
sometimes show that a porosity gradient exists in the
zone of dense welding. Ideally the porosity of a verti-
cal section of a cooling unit should show no change in
the zone of dense welding. However, the ideal is not
usually achieved except in the vitrophyre zone or in
the basal part of some devitrified zones. Thus in some
cooling units, there is a slight, perhaps irregular, but
steady increase in porosity upward from a point near
the base of the devitrified zone to the top of the zone of
dense welding. Above this point the porosity increases
more rapidly and the transition is marked on porosity
curves by a change in slope of the curve. The writer
suggests that where this porosity gradient does exist
in the zone of dense welding, it reflects a lithostatic
pressure gradient, but exists owing to the direct or in-
direct effects of entrapped gas that acted as a deterrent
to uniform completion of the welding process.

Thick hot gas-rich ash flows may weld so fast that
gas is entrapped throughout all but a relatively thin
basal zone. Pumice fragments commonly serve as loci
for the entrapped gas, and crystallization of these
gives rise to streaky eutaxitic folia, some of which are
cavernous and more coarsely crystalline than the
densely welded groundmass shards surrounding them
(pi. 21 K). Unless these tuffs are very young and
fresh, it may lie difficult or impossible to differentiate
between the vapor-phase crystallization around the
entrapped-gas cavities and the true continuous vapor-
phase zone above the zone of dense welding. Thus in
some ash-flow cooling units recognition of the vapor-
phase zone may be of questionable importance. How-
ever, in others differentiation of the vapor-phaze zone,
from vapor-phase crystallization in lenticular or litho-
physal cavities in the zone of dense welding, may be
highly important for the following reasons: (a) Stra-
tigraphic significance; (b) petrologic and mineralogic
interest; (c) because this zone is one of active rising
vapors and it is here that changes may take place in
chemical composition due to vapor-phase transfer of
materials. Preliminary investigations indicate that
appreciable chemical differences (in both major and
minor elements) may be found between this and other
zones.

Mafic phenocrysts, especially biotite, hornblende, and
orthopyroxene, are commonly in part or wholly de-
stroyed by the crystallization processes. Their former
presence may be confirmed by the distribution of

opaque oxides, relicts, and their existence in the vitric
zones. In extreme examples a new generation of mafic
minerals may be formed (biotite, amphibole, fayalite,
and others) .

In fresh rhyolitic rocks the appearance of tridymite
with drusy feldspar usually indicates the presence of
a vapor-phase zone (pi. 21<7 and H). Commonly
these crystal druses are localized in pumice fragments
and show varying degrees of lenticularity depending
on the amount of flattening of the pumice fragment
during welding. The former pumice-tube structures
are often preserved in these crystal aggregates and can
be seen in the field by the unaided eye. In older or
less fresh rocks (middle Tertiary and older) these
vapor-phase crystals have commonly been replaced by
opal, chalcedony, quartz or other minerals and their
original structure may no longer be recognizable.

The writer believes that most of the groundmass
quartz that is seen in some welded tuffs is probably
secondary, having formed through the conversion of
cristobalito or trid 3 T mite by diagenetic or low-grade
inetamorphic processes. However, sometimes quartz
is seen deep in the interior of the devitrified zone of
very thick ash-flow cooling units, where it is probably
primary in the sense that it formed during the cooling
history of the cooling unit. The textures formed are
similar to those seen in granophyric rocks. Conditions
might exist within very hot thick ash flows where
quartz would form in preference to cristobalite as the
groundmass silica mineral, or early formed cristobalite
might be converted to quartz during later stages of
cooling. This would give rise to a zone of grano-
phyric crystallization separating the devitrified zone
into upper and lower parts.

Poor preservation or complete obliteration of vitro-
clastic textures might be expected in very thick cooling
units. Several variables are involved hence the mini-
mum thickness of tuff necessary for the formation of
this zone is problematical. The writer has never seen
what he would interpret to be primary groundmass
quartz in any welded tuff unit less than about 600 feet
thick.

Speculation on the probable nature of a very hot
gas-rich cooling unit that is 2,000 feet or more thick
seems warranted. No doubt thicknesses of this mag-
nitude will be found. Welding would be almost in-
stantaneous throughout most of the sheet and much
gas would be entrapped. Slow cooling could be ex-
pected and a long stage of deuteric activity would pro-
duce a granophyric groundmass in which former pyro-
clastic textures could be completely destroyed.

Without excellent exposures to reveal the contact
relations, such a rock body could easily be interpreted

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ZONES IN WELDED ASH FLOWS

157

as an intrusive mass. Even the contacts might be ex-
pected to show injection phenomena. Some ash flows
are hot enough to cause fusion of underlying glassy
ash or to weld almost completely against low porosity
rocks that are relatively fast heat conductors. Such
welded material under high load could inject cracks
and crevices. Crystallization might also extend to the
base of such a rock body. The zone of granophyric
crystallization might then occupy a large proportion of
the cooling unit

Any ash flow that contains hot gas or is emplaced
at a temperature high enough to crystallize on cooling
should give off gas at its surface. The amount, com-
position, and temperature of this gas, along with other
factors, will determine the degree of alteration of the
surface and upper parts of the deposit including joint
cracks. By this reasoning, and by analogy with historic
ash-flow deposits such as the Valley of Ten Thousand
Smokes (Zies, 1929, p. 1-79) and the Komagatake
deposits (Kozu, 1934, p. 164-174), many ash flows
should show a zone of fumarolic alteration transitional
with the vapor-phase zone and with, perhaps, more
intense alteration localized by deep joints. Surface
sublimates and some near-surface alteration products
are probably rapidly reworked by water entering the
deposits. Some are no doubt removed entirely, but
others are probably lodged in the soft tops of the cool-
ing units.

Where these ash-flow tops are preserved in rocks of
silicic composition, pale but decidedly variegated color
patterns may indicate the presence of former fumarolic
activity. These color patterns are in contrast to the
uniform chalky white, gray, pink, lavendar, red, brown,
or purplish groundmass colors of the vapor-phase zone.
Mild fumarolic alteration has been recognized in pre-
historic deposits by Gilbert (1938, p. 1851-1854), Wil-
liams (1942, p. 86-87), and Mackin (1952, p. 1337-
1338).

COOLING UNIT

Unimpeded cooling of ash flows emplaced above the
minimum welding temperature results in a deposit that
shows a pattern of zones resembling closely (a) plate
2CL4, B, or C; (b) some intermediate stage between the
diagrams; or (c) a vertical segment of these diagrams
or intermediate stages. Such deposits may be called
simple cooling units. Multiple flow units may also
form a simple cooling unit provided they are emplaced
in such rapid succession that there is no hiatus in cool-
ing which cannot be bridged by successive flows (pi.
20Z>).

In a given vertical section of a simple cooling unit
it may be impossible to distinguish between flow units,
and the recognition of partings between them may only

be possible because of horizontal changes in the sheet
Partings that exist in the nonwelded and partly welded
zones will probably be easily seen. However, those oc-
curring in the densely welded zone, especially after
crystallization, may be invisible for many miles, de-
pending on the characteristics of the partings.

Partings between successive ash flows within a single
cooling unit may be marked by the following: (a)
Concentrations of lump pumice; (b) fine- to coarae-
bedded air-fall ash, lapilli, or blocks; (c) bedded ash
from a reworking of the surface of the ash flow by
wind or water; and (d) minor erosional unconformi-
ties. In the absence of these criteria, the ash flows may
in places be distinguished on the basis of abrupt
changes in their physical or chemical makeup. Such
properties as grain size, phenocryst ratios, chemical or
mineralogical composition, color and inclusions should
be considered. In some densely welded tuffs where
partings between ash flows are obscure, preferential
weathering or slight irregularities in density or poros-
ity may suggest their presence. Any, all, or none of
these highly variable factors may be significant in a
simple cooling unit.

Pronounced deviations in the pattern of zones as
outlined for simple cooling units seem to indicate
breaks in the cooling history of given cooling units and
suggest compound cooling. These compound cooling
units can show infinite variation between simple cool-
ing units and separate cooling units. In other words,
a simple cooling unit may, by horizontal gradation,
become a compound cooling unit which, in turn, may
grade into two or more simple or compound cooling
units.

A few of the more obvious features that suggest
compound cooling are: (a) Reversal of relative thick-
ness of upper and lower zone of partial welding; (b)
extensive development of vapor-phase zone below a
devitrified zone of dense welding with a transitional
contact between the two zones; (c) basal nonwelded
zone which is many times thicker than overlying
zones; (d) visible reversals in density or porosity
within the zones of welding exclusive of those related
to differing mineral facies; (e) extensive development
of columnar joints below a zone of dense welding.

Some of the factors contributing to compound cool-
ing are: (a) Unequal areal distribution of individual
ash flows; (b) degree of development of some of the
phenomena which causo the partings listed above;
(c) successive emplacement of ash flows of radically
different temperatures; and (d) periodicity of erup-
tions.

The cooling unit, either simple or compound, is prob-
ably the logical map unit, in most unmetamorphosed

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158

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

rocks. It is a closely limited time unit as well as a
genetic rock unit. Distinguishing between individual
flow units is generally not practical and is impossible
in many situations. In many areas, mapping of at
least the more spectacular zones of the cooling unit is
practical, and in detailed studies, recognition and map-
ping of the zones as integral parts of a unit may help
solve many problems of structure and stratigraphy.

COMPOSITE SHEET

A hypothetical unit, the composite sheet , is discussed
because its existence seems inevitable now that many
of the diverse characteristics of the cooling units are
known. The writer has examined ash-flow deposits
which can be explained only on the assumption that
they are part of a unit of higher rank than the cooling
units. The evidence consists of observed horizontal
change of compound cooling units into separate cooling
units. That is, the composite sheet is composed of
cooling units that may range horizontally through any
or every stage from a single- or multiple-flow simple
cooling unit, multiple-flow compound cooling unit, to
cooling units that are separated by erosional uncon-
formities, other volcanic or sedimentary deposits, or
local hiatuses in time sufficient to allow cooling of one
unit before another is emplaced on top of it. Detailed
mapping for documentation of this concept is neces-
sary.

At any given time during its emplacement cycle the
composite sheet is visualized as undergoing continuous
cooling throughout some of its few tens to few thou-
sands of square miles of area. The merging or overlap
of composite sheets or cooling units from different
source areas would give rise to many complexities.
The time-stratigraphic importance of such a relation
might, be very great, especially if air- fall deposits can
lie related to the ash-flow sheets.

INFLUENCE OF BURIED TOPOGRAPHY

The zonal variations expected to occur where a
simple cooling unit is superimposed on a high or low
feature in the underlying topography are shown in
plate 20 D. The effects are the same as would be ex-
pected from normal horizontal thinning or thickening,
but the changes are more abrupt.

The changes due to buried topography may be strik-
ing in regions of high relief, but in regions of low
relief they are more subtle. For example, the distri-
bution of outcrops of a persistent dense glass zone may
suddenly become erratic. One explanation might be
that the cooling unit was emplaced on an irregular
surface such that the tops of the buried topographic
high areas were roughly coincident with the level in

the cooling unit that marks the transition from the
zone of dense welding to the upper zone of partial
welding. A dense black glass could not form over any
topographic high that, reached this transition level. In
sheets of this type, buried topography will also be re-
flected by gentle irregularities in the surface of the
cooling unit.

Other variables being equal, the thickness of the
cooling unit (producing load pressure) at any point
controls the amount and degree of welding at that
point. Thus the percent of total compaction will be
greater in the thicker parts of the unit, and it is this
differential compaction that, results in surface expres-
sion of buried topography. If two cooling units of
equal emplacement thickness arc of different compacta-
bility, the one with the higher compactability will
show the more irregular surface over equivalent buried
topography.

By careful consideration of plate 20 1), the effect of
buried topography can be predicted for other zones
and different topographic environments. The extreme
abruptness of changes in the cooling-unit surface and
the zones as shown in plate 20 D is due to the vertical
exaggeration of the projection.

Some cooling units (map units) can change abruptly
over a buried escarpment, resulting in thick welded
tuff on one side and a thinner nonwelded or only partly
welded tuff on the other. As shown in plate 20/?, the
thick side of the buried escarpment contains a vitro-
phvre zone and a devitrified zone of dense welding,
whereas the other side is predominantly a “sillar* type
of tuff (p. 151). If such a situation as this were to be
found in deformed and eroded terrane, with poor expo-
sures, the chances of correct interpretation would prob-
ably l>e small even for experienced geologists. It would
present difficulties even under ideal field conditions.
Infinite variation is possible, especially if compound
cooling or composite sheet effects are involved.

REFERENCES CITED

Eulows. II. E., 1055, Welded tuffs of Chiricahua National Monu-
ment, Arizona : Geol. Six-. America Bull., v. fit!, no. 10. p.
1213-1246.

Fenner, C. N„ 1023, The origin and mode of emplacement of
the great tuff deposit in the Valley of Ten Thousand
Smokes: Natl. Geog. Soe., Contr. Tech. Papers. Katina i
ser., v. 1. no. 1. 74 p.

1048. Incandescent tuff flows in southern Peru : Geol.

Soc. America Bull., v. 50, no. 0, p. 870-803.

(JillKTt. C. M.. 1038, Welded tuff in eastern California : Geol.

Soc. America Bull., v. 40. no. 12. p. 1820-1862.

Jcnks. 3V. F., and Goldich, S. S., 1056. Rhyolitic tuff flows In
southern Peru : Jour. Geology, v. 64, p. 156-172.

Kozu, Shukusuke, 1034, The great netivity of Komagatake In
1020: Tsoherinaks mineralog. petrog. Mitt., v. 45, p. 133-174.

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ZONES IN WELDED ASH FLOWS

159

Mackln, J. H., 1052, Hematite veinlets In an lgntinbrite In the
Iron Springs district, southwestern Utah [abs.] : Geol. Soc.
America BulL, v. 63, no. 12, pt. 2, p. 1337-1338.

Marshall. Patrick, 1935, Acid rocks of Taupo-Rotorua volcanic
district : Royal Soc. New Zealand trana., v. 04, p. 323-375.

Ross, C. S., and Smith, R. L„ 1000, Ash-flow tuffs: their origin,
geologic relations, and identification : U.S. Geol. Survey
Prof. Pa|>er 366, In press.

Smith, H. T. U., 1938, Tertiary geology of the Abiqulu quad-
rangle, New Mexico: Jour. Geology, v. 40, p. 933-965.

Williams, Howel, 1942, The geology of Crater Lake Nntlonal
Park, Oregon, with a reconnaissance of the Cascade Range
southward to Mount Shasta : Carnegie lust. Washington
Pub. 540, 162 p.

Zles, E. G., 1929, The Valley of Ten Thousand Smokes ; 1, The
fumaroilc incrustations and their bearing on ore deposi-
tion ; 2, The acid gases contributed to the seu during vol-
canic activity : Natl. Geog. Soc., Contr. Tech. Papers, Kat-
mat scr., v. 1, no. 4, 79 p.

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Deposition of Uranium
in Salt-Pan Basins

By KENNETH G. BELL

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-G

Prepared on behalf of the United States
Atomic Energy Commission and published
with permission of the Commission

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960

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UNITED STATES DEPARTMENT OF THE INTERIOR
FRED A. SEATON, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington 25, D.C. - Price 20 cents (paper cover)

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CONTENTS

Ps«<

Abstract 101

Introduction 101

Uranium in e vaporite minerals and deposits. - ... 102

Summary 109

Literature cited 109

TABLES

p»tf

Table 1. Uranium content of typical deposits of anhydrite and gypsum 104

2. Chemical and mineralogic determinations on samples from a drill core of an evaporitc deposit 160

3. Uranium contents of euxenic dark shales and enclosing dolomites and anhydrite for the Paradox basin. 168

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

DEPOSITION OF URANIUM IN SALT-PAN BASINS

By Kenneth G. Bell

ABSTRACT

Drainage waters carry minute quantities of uranium Into
oceans, Inland seas, and lakes, and when bodies of water evapo-
rate completely in desiccating salt-pan basins, the uranium must
be deposited together with all other dissolved materlala The
ratio of uranium to total evaporlte sediments Is approximately
1 : 2 X 10 7 . The distribution of uranium In salt-pan basin sedi-
ments is not completely known. Some organic-rich muds, and
phosphatlc sediments deposited In desiccating basins may con-
tain uranium In amounts as large as 0.0X percent Uranium
may be adsorbed on clays that are deposited with some evapo-
rlte sediments. These muds, phosphatlc sediments, and clays
may remove nearly all of the dissolved uranium from the water
of some basins. Anhydrite, gypsum, halite, and potassium-
bearing evaporlte minerals probably are the least uraniferous
of all rocks In the earth’s crust; their uranium contents gen-
erally are less than 0.00001 percent. Within salt-pan basins
where oxidizing conditions tend to prevail, and no significant
amounts of organic-rich muds, clays, and phosphatlc sediments
are deposited, highly soluble uranium salts remain In solution
and are deposited only as the basin finally Is completely desic-
cated. These final highly soluble evaporlte sediments are not
likely to be preserved because they are subject to removal by
wind erosion and leaching.

INTRODUCTION

Waters draining lands commonly carry minute
amounts of dissolved uranium. Unless drainage wa-
ters have traversed highly uraniferous terranes, their
contents of uranium generally are fractions of a part
per billion (Fix, 1956; Judson and Osmond, 1955;
Adams, 1954; Rona and Urry, 1952). This uranium
is carried into lakes, inland seas, and the oceans.

Ocean water contains traces of uranium ; the amounts
vary slightly, depending upon total salinity, depth,
and position with respect to shore line. Uranium con-
tents ranging from 0.36 to 3.5 parts per billion (ppb),
oil 0.36 to 3.5 X l(h 8 , for ocean water from different
localities have been reported by various authors (Her-
negger and Karlik, 1935; Foyn and others, 1939;
Koczy, 1950; Nakanishi, 1952; Rona and Urry, 1952;
Stewart and Bentley, 1954; Rona and others, 1956).
There are few published data on the uranium contents
of waters from saline lakes and inland seas. Stewart

552507— so

and Bentley (1954) have reported uranium contents
of 4.7 to 5.3 micrograms per liter (4.7 to 5.3 ppb) in
water samples from Great Salt Lake, Utah. Some
samples from the Salton Sea, Calif., that were ana-
lyzed in the U.S. Geological Survey laboratories con-
tained about 10 ppb of uranium (Butler, A. P., Jr.,
written communication, 1947). Tourtelot (1955) has
stated that highly alkaline water from lakes in west-
ern Nebraska contains 12 to 100 ppb of uranium. The
concentration of uranium in ocean water is about a
10-fold increase over that in drainage waters, and the
concentration in some saline lake waters is greater.

The amount of uranium that can be deposited within
a salt-pan basin normally is very small. If the figure
of 0.1 ppb, indicated by Fix (1956) to be approxi-
mately the average uranium content for water of ma-
jor streams in the United States, is considered to
represent drainage waters in general, then 10 billion
tons, or 7.4 million acre-feet, of water must evaporate
for each ton of uranium deposited during complete
desiccation. An approximate comparison between the
amount of uranium and the total amount of evapo-
rite sediments that can be deposited from a given vol-
ume of water can be obtained by considering the com-
position of the ocean. If the quantity of 35 grams per
kilogram (35,000,000 ppb) for the total salinity of
ocean water (Sverdrup and others, 1942, p. 176-177
and 219) and a uranium content of 1.5 ppb are used,
and desiccation is assumed to be complete, a simple
calculation shows that for every ton of uranium de-
posited about 23 million tons of evaporite sediments
are deposited. If the uranium is assumed to bo uni-
formly distributed in the evaporite sediments the con-
tent would be less than 0.00001 percent.

If an undrained basin that initially held a lake, an
inland sea, or a detached body of ocean water becomes
completely desiccated, all the dissolved material is de-
posited, mostly in the form of saline or evaporite sedi-
ments; a minute portion of the dissolved matter may
be adsorbed on clastic and organic sediments. Uni-

161

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162

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

form, uninterrupted desiccation would cause progres-
sive deposition of the most abundant minerals in the
general sequence: calcium carbonate (as calcite or
limestone) and calcium phosphate (as forms of apa-
tite or dispersed in other minerals), calcium sulfate
(as gypsum and anhydrite), sodium chloride (as ha-
lite), potassium chloride (as sylvite), and magnesium
chlorides and sulfates; other less abundant minerals
may be deposited. This idealized sequence rarely is
obtained because desiccation generally is neither uni-
form nor uninterrupted; cyclic repetition of parts of
the sequence may occur many times, mainly because
of influxes of water into the basin. An important
result of influxes of water is the increasingly high
concentration of very soluble salts in the residual liq-
uid as desiccation reduces the volume and causes pre-
cipitation of slightly and moderately soluble salts
(evaporite minerals) ; the influxes also may bring sub-
stantial amounts of detrital and organic sediments
into the basin. Complete desiccation can be expected
to result in deposition of a final, uppermost thin layer
containing the most soluble evaporite minerals.

Some minerals and compounds in an evaporite se-
quence may be intermixed to a considerable degree.
Calcium phosphate is likely to be dispersed in calcite
(or limestone). Calcite and gypsum or anhydrite may
be intimately mixed or occur in alternating, thin, rela-
tively pure layers. Sylvite commonly is mixed with
halite. After desiccation has ceased, redistribution of
material may result in the formation of secondary
minerals that may be intermixed with the primary
minerals; polyhalite, camallite, and other minerals
that are double salts may be formed in this manner.
Redistribution of material may tend to concentrate
some elements in thin zones. The physical chemistry
of the formation of evaporite minerals, both during
and after desiccation, is not fully known.

There is no analytical evidence that conclusively in-
dicates that uranium minerals are deposited from sa-
line water simultaneously with anhydrite, gypsum,
halite, sylvite, and other minerals of similar solu-
bility. As desiccation proceeds and minerals of in-
creasing solubility are deposited, the concentration of
uranium in the water should increase, and uranium
minerals should be deposited with the final, most solu-
ble evaporite minerals. Clays, shales, and organic
sediments that are interbedded with some evaporite
sediments commonly contain slightly greater amounts
of uranium, probably held by adsorption or chem-
ically combined with organic matter, than the evapo-
rite minerals themselves. Any calcium phosphate min-
erals that are deposited can be expected to contain

small amounts of uranium held in isomorphous sub-
stitution for calcium.

Most of the uranium that enters lakes, inland seas,
and oceans with drainage waters probably is carried
as highly soluble uranyl ions or in complex ions con-
taining a uranyl radical. Inasmuch as uranium salts
that might be present in lake or ocean waters are
highly soluble, a tremendous concentration of such
ions must occur before any evaporite uranium min-
erals are deposited. The hydrous forms of uranyl
chloride (UOiC1j-3HjO) and uranyl sulfate (2UO»
S0 4 ’7H 2 0) are soluble to the extent of several parts
of the salt to one part of water; sodium and potas-
sium chlorides are soluble to the extent of about 0.35
parts of the salt to one part of water at 20° C (Cliem-
ical Rubber Publishing Co., 1956, p. 622-623, 596-597,
570-571). The deposition of halite, sylvite, and other
saline minerals of similar solubility begins long be-
fore saturation points of hydrous uranyl salts are
reached.

A desiccating body of water, particularly if it is
shallow, generally is well aerated and therefore main-
tains an oxidizing environment. This condition is in-
dicated by the common presence of ferric oxides as
impurities in evaporite sediments. ,The oxidizing en-
vironment maintains the dissolved uranium in the
highly soluble uranyl form. A reducing environment,
caused by stagnation of part of the body of water or
by an influx of putrefying organic matter, is either a
local or a temporary condition. Where a reducing
environment exists some uranium may be reduced to
the tetravalent. state and be deposited with organic-rich
muds, or some uranium in the uranyl state may be
sorbed by organic matter and subsequently become re-
duced to the tetravalent state. Many evaporite de-
posits include no sediments that could have been de-
posited only under reducing conditions. Reduction or
sorption of uranyl uranium and its incorporation in
nonsaline reduzates is strictly the result of a local
condition that exists temporarily during desiccation
of some salt-pan basins. It is probable that in most
basins only a smnll part of the uranium in the water
is removed by this mechanism.

Shortly after the desiccation of a salt-pan basin be-
gins, the water becomes permanently saturated with
the carbonate ion in equilibrium with calcium except
for short intervals occurring immediately after large
influxes of water. The carbonate ion is an effective
agent for holding the uranyl ion in solution. Whether
or not it plays a significant role in maintaining the
solubility of uranium in desiccating basins is a moot
question. It is probable that the concentration of

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DEPOSITION OP URANIUM IN SALT-PAN BASINS

163

carbonate ion considerably exceeds that of the uranyl
ion until possibly such time as desiccation is almost
complete. The excess of carbonate ion enhances the
solubility of the uranyl ion, but in an oxidizing en-
vironment the uranyl ion is so soluble that the pres-
ence of carbonate may not be significant. Also, little
seems to be known concerning the effect of the car-
bonate ion on the adsorption of uranium by clays and
other substances.

URANIUM IN EVAPORITE MINERALS AND DEPOSITS

Thin beds of limestone or marlstone may be de-
posited during the initial stage of desiccation in a
salt-pan basin. The uranium content of such lime-
stone and marlstone generally is in the order of 0.0001
percent, or less, except where the rock is appreciably
pliosphatic.

Ocean water contains phosphorus in amounts rang-
ing from 0.001 to 0.1 mg per kg, or 1 to 100 ppb
(Sverdrup and others, 1042, p. 176). Complete pre-
cipitation of this phosphorus in the form of marine
apatite produces about 0.005 to 0.5 milligrams of the
phosphate mineral. The waters of some lakes and
inland sens contain more phosphorus than the ocean
waters. It has been established that marine phos-
phatic sediments generally contain small and variable
amounts of uranium, and some phosphatic sediments
deposited from saline lake waters are also uraniferous.
Investigations by Altschuler and others (1958) have
shown that sedimentary marine apatite typically con-
tains between 0.005 and 0.02 percent uranium that is
considered to be in the apatite structure in isomor-
phous substitution for calcium. Deposition of phos-
phatic sediments from saline waters therefore provides
a mechanism for removal of uranium.

Pure phosphate minerals are not characteristic con-
stitutents of evaporite deposits because the small quan-
tities of phosphates present generally are dispersed in
other evaporite minerals, but all the dissolved phos-
phate must be deposited in any basin that becomes
completely desiccated. The relatively low solubility
of the phosphate minerals causes them to be deposited
simultaneously with the carbonate minerals, and con-
sequently in an evaporite sequence a large portion of
the phosphatic constituents are deposited early and
are found in thin beds of slightly phosphatic marl-
stone or limestone. By use of the values given by
Sverdrup and others (1942, p. 176) for the phos-
phorus content of ocean water and the data of Alt-
schuler and others (1958) for the uranium content of
marine phosphatic sediments it can be seen that the
phosphatic constituent removes a variable portion of
the available uranium (0.005 to 0.5 milligrams of

phosphate mineral containing between 0.0000003 and
0.0001 milligrams of uranium, whereas the available
uranium averages approximately 0.002 milligrams per
kilogram of ocean water). Phosphatic sediment that
rests upon the bottom for a long period of time
continues to take up uranium, and reworked marine apa-
tite may contain as much as 0.1 percent of this element
(Altschuler and others, 1958) . Under some conditions
the phosphatic sediments may remove essentially
all of the uranium from the saline water; under
other conditions only a small fraction of the avail-
able uranium may be removed. Evaporite minerals
that are deposited after the bulk of the carbonate min-
erals generally contain mere traces of phosphates;
such minute quantities of uranium as are in gypsum,
anhydrite, halite, and sylvitc could be associated with
phosphatic impurities.

Large amounts of calcium sulfate minerals are de-
posited during the early stages of desiccation of salt-
pan basins that initially are filled with ocean water.
Gypsum is deposited during desiccation of lakes and
inland seas that are characterized by sulfate-rich wa-
ters. Many thick deposits of anhydrite and gypsum
occur in nearly pure form, that is, they contain less
than 20 percent of other materials. If organic matter
and clays are not the major impurities, these deposits
are essentially devoid of uranium. As indicated be-
low, the sulfate minerals hold only minute traces of
uranium, and the uranium content of impure anhy-
drite and gypsum rocks is contained in the clay, or-
ganic matter, and other substances, and not in the
sulfate minerals.

Many deposits of anhydrite become partly or wholly
converted to gypsum by the hydrating action of
ground and surface waters, therefore, a question arises
concerning the possibility that uranium might be
leached during the hydration. This action undoubt-
edly can occur, but. it is probable that the anhydrite
held no significant amount of uranium. Gamma-ray
logs of test wells drilled through evaporite sequences
indicate that, anhydrite and halite strata show, in gen-
eral, the lowest levels of radioactivity of all sedimen-
tary rocks. Examples of this low radioactivity are
found in gamma-ray logs of many wells drilled
through evaporite-mineral deposits in the Paradox
basin of southwestern Colorado and southeastern Utah
and in the Delaware basin of southeastern New Mexico.

On the west slope of the Humboldt Range, Persh-
ing County, Nev., there are large outcrops of gypsum,
one of which has an area of about a square mile. The
principal impurities in this gypsum are carbonate min-
erals. The outcrops are covered by a layer of weath-

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164

8H0BTER CONTRIBUTIONS TO GENERAL GEOLOGY

ered gypsum a few inches thick mixed with a small
amount of wind-deposited sediment derived mostly
from dust and salt flats of the adjacent Humboldt
Sink. Radioactivity measurements made on the out-
crops with a scintillation counter gave readings of ap-
proximately 0.003 milliroentgens per hour when the
instrument was held about 2 feet above the weathered
gypsum surface. The readings were almost nil where
taken inside some prospect tunnels. The small amount
of energy measured on the outcrop probably was pre-
dominately cosmic radiation. A similar condition ex-
ists in White Sands National Monument, N. Mex.,
where dunes of gypsum sand cover large areas. A
scintillation counter gave no measurable reading dur-
ing a traverse of some of these dunes (A. P. Pierce
and J. W. Mytton, U.S. Geological Survey, oral com-
munication, 1957).

Secondary uranium minerals have been found in a
few bedded gypsum deposits, for example in the Para-
dox member of the Hermosa formation in Gypsum
Valley, San Miguel County, Colo., and in the Brule
formation, Dawes County, Nebr. These uranium min-
erals are epigenetic and have been introduced by
ground and surface waters. The Brule formation is
nonmarine, and its gypsiferous member was deposited
from a lake of sulfate-rich water in which the salinity
apparently did not reach the point where minerals
more soluble than gypsum were deposited. A field
examination in sec. 8, T. 34 N., R. 47 W. showed that
anomalous radioactivity, and uranium minerals, occur
at scattered points along the gypsum outcrop where
there are intermittent ground-water seeps. The flow
of water is insufficient to make surface streams, ex-
cept during unusually wet periods, but does cause small
landslides and collapse of steep slopes. The uranium
minerals are carnotite, autunite, and sabugalite
[Hal(U0 3 ) 4 (P0 4 ) 4 -16 H 3 0] (Dunham, 1955). They
are concentrated on the surfaces of the outcrops and in
the thin soil mantle where the ground water evapo-
rates. Where there is no evidence of ground-water
seepage, neither anomalous radioactivity nor uranium
minerals can be found.

Two samples of the bedded gypsum from the Brule
formation contained 0.0008 and 0.0001 percent of ura-
nium (Nos. 260461 and 260462, table 1). Sample no.
260461 was light brown, had a strong fetid odor, and
contained a small amount of organic matter that prob-
ably had sorbed the apparently anomalous amount of
uranium; sample 260462 was white and odorless. The
samples contained about 5 percent of acid-insoluble
matter. The waters that formed the Brule lake drained
a terrane characterized by sedimentary deposits con-
taining an abundance of volcanic ash and therefore

probably contained greater-than-average quantities of
uranium. This condition is reflected in the abnor-
mally high uranium content of the gypsum. It is
unlikely that the minute, although anomalous, amount
of uranium in this gypsum accounts for the secondary
uranium minerals on the surfaces of the outcrops and
in the topsoil. It is more likely that the uranium in
the secondary minerals is leached from tuffaceous clays
in the vicinity and is deposited on the outcrops and in
the topsoil where the water evaporates.

Anhydrite is anomalously radioactive within or in
the vicinity of some petroleum and natural gas fields,
for example, in the Permian formations of the Pan-
handle field of Texas. Investigations have shown that
the radioactivity originates in uraniferous organic
substances that have been epigenetically emplaced in
secondary anhydrite; the primary anhydrite, which
was deposited as an evaporite sediment, is no more
uraniferous than primary anhydrite found elsewhere
(A. P. Pierce, U.S. Geological Survey, oral commu-
nication, 1957).

The uranium contents of some typical deposits of
anhydrite and gypsum are presented in table 1. Three
samples (Nos. 252251, 252252, and 260461) contained
small amounts of organic matter. These three sam-
ples contained anomalous quantities of uranium, which
possibly were sorbed by the organic matter.

Saline minerals, such as halite, sylvite, camallite,
and others of similar solubility contain so little ura-
nium that the amount cannot be determined with pre-

Table 1. — Uranium content of typical deposits of anhydrite and

gypsum

[ Anulyst*: D. L. Fergujon, H. H. Linn. W. J. Mountjoy. C. O. Angelo, J. P. Sehuch,
ana K. J. Fenrily.)

8am pU
No.

Material

Add-

Insoluble

matter

percent

80,

prrooct

Uranium

percent

202250

252251

202364

200489

200400

200401

260462

0.0001

.0004

.0002

.0001

.0008

.0001

10.2

8.0

5.9

88.5

39.9

40.1

41.8

Note. — Source* of Rumple*:

252250. Sample of core chips, Shell Oil Co.’s Desert Creek
No. 1 well, 8WK8EXNWtf sec. 2, T. 42 8., R. 23
E., San Juan County, Utah, depth 5,122)4 ft.

252251. Same as source of sample 252250; depth 5,12454 ft.

252254. Sample of core chips, Reynolds Metal Co.’s Hatch
No. 1, sec. 4, T. 30 S., R. 24 E., San Juan
County, Utah, depth 5,797-5,790 ft.

260459. Sample from prospect tunnel, W}4 sec. 27, T.
26 N., R. 32 E., Pershing County, Nev.

260460. Sample from abandoned Regan mine, approxi-
mately 12 miles south of Yerington, Nev.

260461. Sample from outcrop of gvpBiforous member of
Brule formation, wX sec. 3, T. 34 N., R. 47 W.,
Da we* County, Nebr.

260462. Samplo from same locality as sample 260461.

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DEPOSITION OF URANIUM IN SALT-PAN BASINS

165

cision by standard methods of chemical analysis. There
are but few published data on this subject Kem6ny
(1941) has reported that the uranium contents of rock
salt, sylvite, and camallite from Germany and Aus-
tria, determined by radiometric methods, average
0.0006 percent (6 X 10- 10 g/g). Gentner and others
(1954) have reported a uranium content of 0.00001
percent (IX 10~ 10 g/g) for sylvite from Buggingen,
Germany ; the determination was made by a method of
counting alpha tracks on an emulsified plate. A few
samples of potash ores, consisting mainly of halite,
sylvite, and polyhalite, from the Carlsbad district,
New Mexico, have been tested for uranium in the
Geological Survey laboratories. The uranium con-
tents of the samples were less than 0.0001 percent, so
no attempt was made to determine them precisely. All
uranium determinations by the Geological Survey lab-
oratories were made by fluorometric methods.

These meager data do not indicate enrichment of
uranium in evaporite sediments. They do not war-
rant any conclusions regarding the proportionate rate
at which uranium is deposited during stages of desic-
cation represented by halite and sylvite.

The clays and the iron and aluminum oxides that
are deposited with saline minerals probably as a rule
are considerably more urnniferous than the saline
minerals themselves. Some information about the dis-
tribution of uranium between water-soluble evaporite
minerals and water-insoluble matter was obtained by
analyzing several samples taken from a drill core re-
covered from potassium-bearing beds in the Salado
formation of Permian age, Delaware basin, N. Mex.
The samples were cut from a 19-foot length of core
from a stratigraphic section that includes two thin
zones having large contents of clays. The clays evi-
dently were deposited when large influxes of sedi-
ment-bearing water entered the basin. The analytical
data are presented in table 2.

The sections of core were split lengthwise, and one
part was crushed and mixed to provide material for
analysis. Uranium in the total sample was deter-
mined by a fluorometric method. The samples were
then separated into water-soluble saline minerals,
water-insoluble but acid-soluble saline minerals, and
water- and acid-insoluble matter by the following pro-
cedure: The samples were leached by weighing 1
gram of the substance into a tared sintered glass cru-
cible of medium porosity, 10 ml of water were added,
the slurry was stirred briefly, and the resulting solu-
tion was drawn by vacuum into a volumetric flask;
this procedure was repeated ten times for a total of
100 ml of water; the water-soluble evaporite minerals,

such as halite and sylvite, and a small portion of the
slightly water-soluble minerals, such as polyhalite and
anhydrite, were dissolved in the water leachate; the
crucible and contents were then dried under a vacuum
of less than 1 cm of mercury in a desiccator containing
anhydrous calcium sulfate, were weighed, and the
leaching procedure repeated with 1:1 hydrochloric
acid ; the acid leachate contained most of the polyhalite
and the calcium sulfate minerals, as well as phosphate
and carbonate minerals; the water- and acid-insoluble
matter remaining in the crucible consisted of clay
minerals and other clastic sediments, which were then
dried and weighed.

An attempt was made to determine the uranium
contents of the water-soluble leachates by the fluoro-
metric method, but the quantities of uranium present
were below the threshold of the procedure used, or
less than 0.00002 percent. Uranium in the acid leach-
ates was determined, but there is no assurance that
the values obtained are indicative of the uranium con-
tents of the water-insoluble but acid-soluble minerals;
some of this uranium may have been adsorbed on clays
and was removed by the acid. Uranium in the water-
and acid-insoluble matter was obtained by difference,
and again there is no assurance that the values indi-
cate the true quantities of uranium because some ura-
nium may have been removed by the acid.

The data presented in table 2 indicate that most of
the uranium is concentrated in the water-insoluble but
acid-soluble matter and the water- and acid-insoluble
matter. The water-soluble matter contains extremely
small amounts of uranium, the amount being less than
0.00002 percent of the total sample for all samples
analyzed. The uranium contents of the water-insolu-
ble but acid-soluble matter are very small and show a
positive correlation with the total uranium contents
of the samples; the latter feature may be an indica-
tion of extraction of uranium from the water- and
acid-insoluble matter by the acid.

One sample (No. 254465, table 2) is of especial in-
terest because it represents a clay-rich zone about 6
inches thick. Unfortunately about three-quarters of
the material from this zone was lost during drilling;
that which was recovered was completely consumed in
the various chemical analyses. The megascopically
visible constituents of the sample were coarse crystal-
line halite, sylvite, and polyhalite, and galls and
stringers of greenish-gray clay consisting of montmo-
rillonite, illite, and kaolinite and (or) chlorite. The
analytical data (table 2) indicate the presence of a
surprisingly large amount of uranium; two splits of
the core contained 0.0078 and 0.038 percent uranium,

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166

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

o«

o-3

■3?

j o

“a

•o

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DEPOSITION OF URANIUM IN SALT-PAN BASINS

167

or 78 and 380 (ppm) ; the acid-soluble matter of a
third split, obtained after removing water-soluble mat-
ter, contained an amount, of uranium corresponding to
0.040 percent (400 ppm) of the sample. The range
of values is attributed to the coarse heterogeneous
character of the material and the improbability of
making three identical splits of the core. This sam-
ple contained about 19 percent water- and acid-insolu-
ble matter, about 2.6 percent carbonate as C 03 = , and
about 0.041 percent phosphate as PO. " .

Above average quantities of uranium and phos-
phate were found in the second thin clay-rich zone
represented by samples 2544G8 and 254469 (table 2).
The amount of uranium in sample 254468 was 0.00065
percent (6.5 ppm) and of phosphate as PO, s was
0.009 percent (90 ppm).

These clay-rich samples contained no visible ura-
nium minerals and no fluorescent substance. Some
uranium undoubtedly was combined with the phos-
phate constituent, but the amounts of uranium found
seem to be considerably in excess of what reasonably
could be accounted for by this combination. Some of
the uranium could have been adsorbed on clays, and a
finely dispersed uranium mineral could have been
present.

The clay -rich zones undoubtedly represent interrup-
tions in the desiccation of the basin caused by large
influxes of water carrying dissolved matter and much
fine-grained sediment. Such influxes could have re-
sulted from occasional floods that washed the adja-
cent terrain. "When the floods subsided, desiccation
immediately was resumed ; fine-grained suspended clas-
tic sediments settled to the bottom and became mixed
with the initial evaporite layer which contained some
phosphatic and carbonate constituents. This action
provided at least two mechanisms for removal of ura-
nium from the basin water, adsorption on clays, and
combination with phosphatic constituents. It seems
probable that most of the uranium thus removed was
already in the basin prior to the influx that brought
in the clays.

Stagnant, anaerobic conditions may exist, tempo-
rarily within the water of parts of some desiccating
salt-pan basins. If there is an influx of fine-grained
clastic sediments and organic matter during such pe-
riods, organic-rich dark muds or limy muds may be
deposited and ultimately become shales. Some of such
shales that are slightly phosphatic may be anom-
alously radioactive and contain uranium in the range
of 0.00X to 0.0X percent- On the other hand, organic-
rich muds can be deposited in oxidizing environments,
and subsequently a zone in which reducing conditions

exist may form in them although the uppermost layer
of mud and the water above it remain in an oxidizing
condition ; under these circumstances the reducing zone
is insulated from the main body of water, and the only
uranium that can be sorbed is that in the connate wa-
ter, consequently the muds do not become significantly
enriched in uranium. Uranium-rich muds generally
are deposited in reducing environments, and if the
bottom surface remains in a reducing condition, sorp-
tion of uranium in a particular layer may continue
for as long as water can move freely past or through it.

In the Paradox basin of southwestern Colorado and
southeastern Utah some thin beds of euxenic dark-
gray and black shale are interspersed among the car-
bonate and saline deposits of the Paradox member of
the Hermosa formation. They are good marker beds
for stratigraphic correlation because they show anom-
alously high radioactivity on gamma-ray logs. The
characteristics and possible origin of these dark-shale
beds have been discussed by Wengerd and Strickland
(1954). The uranium contents of a few samples of
some of these dark-shale beds and of the dolomites and
anhydrite that enclose them have been determined.
These data are presented in table 3. The samples were
chipped from drill cores and represent the only mate-
rial that was available at the time of this investiga-
tion. The most uraniferous sample, No. 252252, con-
tained 0.0057 percent uranium. In general, the ura-
nium contents of these shale beds are about an order
of magnitude higher than those of the enclosing dolo-
mites and anhydrite. Probably some uranium is
sorbed by organic matter and phosphatic sediments
and thereby is removed from the saline during the
deposition of sediments such ns those that formed the
shales in the Paradox member. This mechanism op-
erates only temporarily in a few basins and probably
removes only a small part of the dissolved uranium
from the water.

Table 3. — Uranium contents of euxenic dark shales and enclosing
dolomites and anhydrite from the Paradox basin.

(Analysts: O. O. Angelo. J. P. Schncb, and E. J. Fannally)

Sampto

No.

Depth

(toot)

Description

Uruntum

peroMit

Shell Oil Co.’s North Boundary Botte No. 1 Well. C SWM NKJ4 0 «. 33, T. 42 S.,
R. 22 B. t Son Juan County. Utah

252220

4.212

4,615

4.617

0 0000

232221

. 0007

252222

.0000

252223

4.6I8H

s. earn

4.«m

4.622

.0013

252224

.0005

252225

.0004

252226

.0011

2S2227

4.623

4.625

4.628

.0003

252228

.0003

25222V)

.0006

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168

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Table 3. — Uranium contents of euxenic dark shales and enclosing
dolomites and anhydrite from the Paradox basin — Continued

Samplo

Depth Description

Uranium

No.

(feet) |

percent

Superior Oil Ce.’e So. l-» N«r»Jo Well. C NW« SW)i •». », T. 41 8.. R. 26 B„
Son Juan County. Utah

2 52230

6,048-0.040
6. 053-8. 054

6.055- 6.056
6.OH3-6.057

8.057- 6.058

6.058 - 6. 039

6.056- 6,060
6,061-6.062

0.0008

252231

.008

.0007

252233

.0007

252234

.0008

.0006

25223*

.0006

252237

.0010

252238

6.062- 6.003

6.063- 6.064

6.064- 6.066
6,066-6,066
6.067-6,068

.0010

252239

.0010

252240

.0012

252241

.0007

252242

.0006

252213

6^ 066-6. 089
8. 060-6. 070

6.070- 0.071

6.071- 6.072

6.072- 6,073

6.073- 6.074

.0007

252244

.0011

252245

.0032

252240

.0013

252247

.0007

252248

.0002

Shell OU Co.'a Deaer t Creek No. 1 Well, 3W« HEM N WH oec. 2. T. 42 8., #.3E,
San Juan County, Utah

252249

5. 122*4

0.0001

6, 124*>
A. 126
6.127
6. 12Sh

.OCOl

MW. 1

.0004

252252

Black shale

.0057

.0001

Reynold! Metal Co.’a Hatch No. 1 Well. aee. 4. T. St 8.. R. 24 E., San Juan County,

Utah

252254

6, 797-5. TS0
S.7SO-6.7MM
8.7Wt-6. SCO

0.0008

252256

.0017

2*»?2-5A

.ocas

The data presented above indicate that the distri-
bution of uranium in sediments deposited in desiccat-
ing salt-pan basins is not uniform and is not com-
pletely known. In attempting to determine the dis-
tribution, a major difficulty arises from the fact that
the amounts of uranium and its compounds involved
are very small in comparison to the total bulk of sedi-
ments. It is known that in some salt-pan-basin de-
posits uranium is not uniformly distributed among
the various sedimentary materials but is relatively en-
riched in clays, in phosphatic sediments, and in some
beds of organic-rich, dark shale that were deposited
in reducing environments. It is possible that in some
basins essentially all of the dissolved uranium can be
removed from solution by inclusion in clays and phos-
phatic and organic sediments. Within basins where
such sediments are not deposited, or are deposited in
very small amounts, it seems most likely that a sub-
stantial part of the uranium must remain in solution
until the bittern finally evaporates.

The probability that the concentration of uranium
increases continuously in the water of some salt-pan
basins even though substantial amounts of clays, phos-
phatic sediments, and carbonate and evaporite min-
erals are deposited is indicated by the comparatively

high concentrations of uranium in the waters of the
Salton Sea, Calif., and Great Salt Lake, Utah. Much
of the water entering Great Salt Lake drains terranes
to the east and northeast that are composed in part of
highly phosphatic formations (Phosphoria and Park
City formations). Rather extensive deposits of cal-
careous oolites that contain small amounts of phos-
phatic material are found along parts of the shore,
and the oolites still are being formed; black, organic-
rich clays are being deposited along other parts of the
shore (Eardley, 1938). The uranium contents of the
oolites and black clays are unknown. Even though
these sediments are types that commonly are enriched
in uranium from solution, the lake water has about
twice the concentration of uranium as does ocean wa-
ter. The concentration of uranium in the Salton Sea
(10 ppb) is about four times that of ocean water.

It already has been pointed out that within desic-
cating salt-pan basins oxidizing conditions tend to
prevail and reducing conditions tend to be localized
and often are of brief duration. As a consequence,
most of the dissolved uranium is maintained in the
highly soluble uranyl state. The uranyl salts are 90
highly soluble that it is reasonable to assume that the
water in a basin must evaporate completely to cause
deposition of uranium that is not sorbed by clays, or-
ganic matter, and phosphatic sediments. If the wa-
ter never evaporates completely it is unlikely that any
uranium salts will be deposited. If a basin becomes
completely desiccated, a small but appreciable amount
of uranium minerals should be deposited in a final
layer of highly soluble evaporite minerals. Such ura-
niferous deposits apparently are unknown; the rea-
son is that they are readily susceptible to removal.

The surface of a dried-up basin, or even a partly
dried-up basin, is subject to wind erosion that can
remove considerable amounts of sediment Anyone
who has been in the vicinity of the Bonneville salt
flats of Utah, or the smaller salt flats in the Carson
and Humboldt Sinks of Nevada, in the Mohave and
Death Valley areas of California, or the bolsons of
west Texas on windy days can attest to the fact that
wind moves large amounts of evaporite minerals. An
indication of the amount of evaporite material that
can be so moved is given by Eardley and others (1957,
p. 1151) in discussing wind erosion in the Bonneville
basin of Utah. They stated: “The writers postulate
that the wind removes about 3,000,000 tons of salt an-
nually from the Great Salt Lake desert. This is car-
ried by the wind out of the drainage basin.” It is
reasonable to assume that an exposed layer of uranif-
erous evaporite minerals could be removed by wind
within a very short period.

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DEPOSITION OF URANIUM IN SALT-PAN BASINS

169

Uraniferous evaporite minerals would have to be
covered by some other kind of sediment immediately
after they were deposited in order to be preserved
from wind erosion. Even then, these very soluble
minerals would be leached by the first passage of wa-
ter through the sediments. This water would remove
the highly soluble salts, including uranium salts, from
the places of initial deposition and transport them
laterally or downward, thereby dispersing them
through much larger volumes of rock and sediment,
or it would bring them to the surface to form depos-
its of efflorescent minerals that subsequently would
become dispersed.

There is little possibility that a final deposit of ura-
nium-rich evaporite sediments can be preserved in a
salt-pan basin.

SUMMARY

In summary, it can be stated that evaporite sedi-
ments deposited in salt-pan basins are probably the
least uraniferous of all rocks. Their uranium con-
tents average less than 0.00001 percent. Tins condi-
tion results from (1) the paucity of uranium in ocean
and surface waters, (2) the oxidizing environments
that generally exist within the evaporating bodies of
water, (3) the great solubility of uranyl chlorides and
sulfates and uranyl carbonate complexes, and (4) the
likelihood that any uraniferous evaporite sediments
that might be deposited are removed by wind erosion
or by leaching. Analytical work that would indicate
whether uranium is deposited at a fairly uniform rate
throughout the desiccation of a salt-pan basin or tends
to remain in solution until the basin finally dries out
has not been done. Theoretical considerations indi-
cate that in some basins most of the uranium can be
removed from solution through sorption by clays,
phosphatic sediments and organic-rich muds; in other
basins the bulk of the uranium should remain in solu-
tion until such time as desiccation is almost complete.

LITERATURE CITED

Adams. J. A. S., 1954, Uranium contents of Wisconsin rivers
and their use In geochemical prospecting [aba] : Geol. Soc.
America Bull., v. 65, p. 1225.

Altschuler, Z. S., Clarke, R. S., Jr., and Young, E. S., 1958,
Geochemistry of uranium In apatite and phosphorite : U.S.
Geol. Survey Prof. Paper 314-D, 50 p.

Chemical Rubber Pub. Co., 1950, Handbook of chemistry and
physics : 88th ed. Cleveland. 3206 p.

Dunham, R. J., 1955, Uranium minerals In Ollgocene gypsum
near Chadron, Dawes County, Nebr. : U.S. Geol. Survey
TEI-525, 31 p.. Issued by U.S. Atomic Energy Comm. Tech.
Inf. Service Ext, Oak Ridge, Tenn.

Eardley, A. J., 1938, Sediments of Great Salt Lake, Utah: Am.
Assoc. Petroleum Geologists Bull., v. 22, p. 1305-1411.

Eardley, A. J., Gvosdetsky, Vasyl, and Marsell, R. E., 1957,
Hydrology of Lake Bonneville and sediments and soils of
its basin : Geol. Soc. America Bull., v. 68, p. 1141-1201.

Fix, P. F., 1956, Hydrogeochemical exploration for uranium, in
Contributions to the geology of uranium and thorium by
the United States Geological Survey and Atomic Energy
Commission for the United Nations International Confer-
ence on peaceful uses of atomic energy, Geneva, Switzer-
land 1955: U.S. Geol. Survey Prof. Paper 300, p. 607-671.

Fbyn, E., Karlik, B., Petterson, H., and Rona, E., 1939, Radio-
activity of sea water: Nature, v. 143, p. 275-276.

Gentner, W„ Goebel, K., and Prflg, R., 1954, Argonbestlmmungen
an Kallum-Minerallen. III. Vergleichende Messungen naeh
der Kallum-Argon- und Uran-Hellum Methode: Geochlm.
et Co8mochim. Acta, v. 6, p. 124-133.

Hernegger, Friedrich, and Karlik, Berta, 1935, Die quantitative
Bestlmmung sehr kleiner Uranmengen un der Urangehalt
des Meerwassers: Sltzungsberichte Academle der Wissen-
schafter in Wien, Math.-naturw. KI. Abt. Ila, v. 144, p. 217-
225.

Judson, Sheldon, and Osmond, J. K., 1955, Radioactivity In
ground and surface water: Am. Jour. Scl., v. 253, p. 104-
116.

Kemdny, Etel, 1941, Uran- und Radiumgehalt von Steinsalz und
Sylvln : Sltzungsberichte Akademie der Wlssenschafter in
Wien, Math.-naturw. Kl., Abt Ila, v. 150, p. 193-207.

Koczy, Gerta, 1950, Weitere Uranbestlmmungen an Meerwas-
serproben : Sltzungsberichte Akademie der Wlssenschafter
in Wien, Math.-naturw. Kl., Abt. Ila, v. 168, p. 113-12L

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uranium. V. The uranium content of sea water: Chem.
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Uranium determination in sea water: Am. Geophysical
Union, Trans., v. 37, p. 697-701.

Rona, Elizabeth, and Urry, W. D., 1952, Radioactivity of ocean
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In sea water: Science, v. 120, p. 50-61.

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oceans. Their physics, chemistry and general biology:
New York, Prentice-Hall. Inc., 1087 p.

Tourtelot, H. A., 1955, Uranium content of water In the Great
Plains region of Nebraska and in adjacent states [abs.] :
Geol. Soc. America Bull., v. 66, p. 1627-1628.

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Digitized by Google

Foraminifera From
Onotoa Atoll
Gilbert Islands

By RUTH TODD

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-H

Ecologtc study of Recent assemblages from
beaches , reefs , and shallow lagoon floor

UNITED STATES GOVERNMENT PR I NTI NG OFFI CE, WASH INGTON : 1961

UNITED STATES DEPARTMENT OF THE INTERIOR
STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.

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CONTENTS

Tatct

Abstract 171

Introduction 171

Material studied .. 171

Locality data 173

Fauna 170

Wet samples 181

Pose

Examination of fish contents 182

Foraminifera from pits 184

Local distribution of CcUcarina and Daculogypsina 180

Notes on selected species 180

References cited 188

Index 189

ILLUSTRATIONS

[Plates 22-25 follow index)

Plate 22. Recent benthonic Foraminifera from Onotoa Atoll.

23. Recent benthonic Foraminifera from Onotoa Atoll.

24. Recent planktonic Foraminifera from Onotoa Atoll.

25. Foraminifera sands from Onotoa Atoll.

Fiourb 40. Map of Onotoa showing locations of samples studied and major occurrences and relative abundance of Cakarina

and liaculogypsina

41. Diagrammatic sections of 7 dug pits on the northern main island of Onotoa Atoll

172

185

TABLES

Table 1. Distribution of Recent Foraminifera of Onotoa Atoll 177

2. Occurrence of Foraminifera in stomach and gut contents of fish from the lagoon at Onotoa Atoll 183

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

By Ruth Todd

ABSTRACT

The distribution of 168 species and varieties of smaller Fo-
raminifera is recorded within the lagoon and on the reefs and
beaches of Onotoa Atoll as represented by 33 surface samples
and 23 pit samples. Nearly all the species are well known in
shallow-water sediments of the tropical Pacific; 7 are indetermi-
nate; none are described as new. The lagoon collecting localities
were all but one from depths no greater than 20 feet, and mostly
from areas protected from the open ocean. Preservation in
alcohol of 24 samples permitted a staining process to be used and
an estimate to be made of the very small live-dead ratio, and
determination of the living places of certain of the species.

Recognition of two major distinctive habitats — (a) reef sur-
faces and their adjacent ‘slopes and (b) limrsund bottom of the
lagoon -is based in part on the relative abundance of species
and in part on the presence of live (stained) specimens.

Four species — Calcarina xpengltri, Baculagypsina xphaerulata,
Amphixtegina madagaxcarienxix. and Marginnpora vertchralis—
make up quantitatively most of the foraminiferal material in
the reef sediments. Major foraminiferal constituents of the
lagoon sediments are, in quantitative order: Amphixtegina
madagaxcarienxix, lleteroslegina suborbicularix, Marginopora
verUbralix, and Elphidium slriatn-punctatum. Quantitatively
insignificant because of their smaller sire, but common or abun-
dant in most samples, are many species of mitiolids and several
species in each of the following families: Textulariidae, Pcnero-
plidne, Buliininidae, Discorbidae, Cymbaloporidae, Anomalini-
dae. and Planorbulinidae. Glohigerinids are present, but only
rarely, and appear to have come in from the open ocean through
breaks in the reef. Seventeen other families are represented
mostly by rare or scattered occurrences.

Stomach and gut contents of 22 fish were found to contain
Foraminifera tests nearly as varied as the naturally occurring
fauna. The fact that most of the individual fish did not contain
as great a variety as the composite of all the fish suggests a
rather localized feeding area for each fish.

Seven pita provide short sections -a maximum of 10 feet— into
the sediments that make up the northern main island. These
sediments are interpreted as beach sands overlying and transi-
tional to reef flat deposits.

INTRODUCTION

Onotoa Atoll is a “dry" atoll (referring to its rainfall
(Cloud, 1952, p. 10-15]) in the southern part of the
Gilbert Islands. It is elongate northwest-southeast
and bordered nearly continuously on the northeast
(windward) and south sides by narrow islands but either
open to the ocean or protected by discontinuous living

coral reefs on the southwest side (fig. 40). Its dimen-
sions are roughly 12 miles long and 4 to 5 miles wide.
Latitude and longitude at its northwestern end are
1°46' S. and 175°30' E. Its physical description may
be found in a preliminary report by Preston E. Cloud,
Jr. (1952), who in 1951 made the collections upon
which this study is based.

Acknowledgments . — I am indebted to Preston E.
Cloud, Jr., for making available the well-documented
material and to John E. Randall for the identifications
of the fishes studied. For helpful suggestions and dis-
cussions I am grateful to Preston E. Cloud, Jr., and to
Richard Cifelli. Invaluable help in preparation of
material and tabulation of results was received from
Doris Low. The illustrations of the individual speci-
mens of Foraminifera were made by Elinor Stromberg.

MATERIAL STUDIED

Samples were studied from the following areas of
Onotoa Atoll:

(1) Area open to ocean on west (leeward) side of atoll

(7 samples from depths between 3 and 18 feet);

(2) Lagoon:

(a) Southern part (8 samples from depths be-

tween 6 and 17 feet, with 1 exception,
f 11683 (GOC-55] collected from 48 feet)

(b) Central and northern part (7 samples from

depths down to 20 feet);

(3) Reef areas (3 samples from leeward side of atoll

and 2 from windward);

(4) Southern part of atoll (4 samples of fine sediment

and incipient beachrork);

(5) Islands along the east (windward) side of atoll

(a) Beach sands (4 samples)

(b) Material from pits having depths from 20

inches to 1 IK feet. The pits start in beach
sands, in which many of the specimens are
severely corroded (13 samples), and pene-
trate through progressively richer transi-
tional sediments (7 samples) into sedi-
ments of a reef -flat horizon (3 samples).

171

172

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Fiauiuc 40.— Map of Onotou showing locations of samples studied and major occurrences and relative abundance of Co/corina and Baculowptina.

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

173

LOCALITY DATA

The following locality and sample descriptions, taken
from P. E. Cloud’s field notes, are arranged in order of
their U.S. Geological Survey Foraminifera locality
numbers. They include pertinent details of the various
environments from which the Foraminifera from Onotoa
Atoll, Gilbert Islands, were derived.

v.s.a.s. toe.

JVo.

1116-44.

U.S.O.S. toe.
No.

fl 1639-1116-43.

f 11639.

f 11640.

111641.

111642.

f 11643.

fl 164 4-f 11649.

Field localities and descriptions

GQC-l. Southern part of northern main
island, about 1,100 ft S. 41° E. from east,
(inshore) end of lagoon-side jetty at Govern-
ment Station and 325 ft inshore from sea beach
along line bearing S. 87° \V. at Pacifio Science
Board campsite. Pit in which water level
fluctuated with tide. Pit section in descend-
ing order, with unit thicknesses, is:

GOC-1A. 99+ percent medium-grained Cal-
carina sand, dark brownish gray from organic
matter. Roots very abundant, up to seven-
eighths of an inch in diameter. Foraminifera
worn or eroded by organic acids. Subaerial
accumulation?. Top 9-10 in.

GOC-lB. 99+ percent medium-grained dark -
tan Colcarina sand, abruptly gradational to
f 11639 (GOC-1A). Sample fl 1640 differs
only in organic content, abundance of roots,
and good preservation of Catcarina, suggest-
ing only slight transportation. Roots mod-
erately abundant, as much as one-half of an
inch in diameter, cutting off abruptly at
base. Subaeriul accumulation?. Thickness,
16-17 in.

GOC-1C. Similar to fll642 (GOC-lD), which
follows, but has alternating layers of semi-
indurated to indurated material. Basal 1-4
in. indurated. Roots rarely extend into unit
C. Probably deposited along beach near
reef flat. Thickness, 7-10 in.

GOC-lD. Weakly indurated to nonindurated
medium-grained limesand, 80 ± percent well-
preserved Calcarina and 20 ± percent other
Foraminifera and detrital CaCOj, much of
it quite fine grained. Other Foraminifera
include Marpinopora. Color is light tan to
flesh. Thickens where fll641 (GOC-1C)
thins and unit C apparently represents in-
cipient beachrock at top of unit D. No
roots. Probably deposited along beach near
reef flat. Thickness, 14-17 in.

GOC-1E. Zone of llcliopora. About 70 per-
cent blue coral of which much may be but
none is certainly in position of growth; 30±
percent interstitial limesands are coarse to fine
grained, light tan to flesh, of detrital CaCOs
and Foraminifera. Marginppora abundant;
Calcarina common; echinoid spines occa-
sional. Interpreted as reef-flat horizon, built
up to about low tide level and then overrun
by beach of f 1 1 642 (GOC-lD). No roots.
16 in. above watermark. Thickness, 25 in.

GOC-2. Southern part of northern main
island, about 940 ft S. 25° E. from east (in-

fl 1645.

fl 1646.

fl 1647.

f 1 16-48.
f 11649.
fl 1650-111653.

111650.

111651.

None.

Field localUiu and duerlpUoiu

shore) end of lagoon-side jetty at Govern-
ment Station and 660 ft inshore from sea
beach along line bearing 8. 87° W. at Pacific
Science Board campsite. Pit similar to
GOC-1. Pit section in descending order,
with unit thicknesses, is:

GOC-2A. Medium- to fine-grained limesand,
dark brownish gray from organic matter.
Worn Calcarina about 60 percent ; remainder
of detrital fines. Roots uncommon. Some
stones as much as three-fourths of an inch in
diameter. Top 5 in.

GOC-2B. Medium-grained limesand. Worn
Calcarina about 70 percent with occasional
pebbles as much as three-eighths of an inch
in upper 7 in. Up to 95+ percent worn
Calcarina below. Remainder is detrital
CaCOj. Tan to flesh colored; darker above
than below. Roots abundant, as much as
three-eighths of an inch in diameter. Thiok-
ness, 19 in.

GOC-2C. loose CaCOj gravel composed of
50 percent CaCOj pebbles as much as 2)$ in.
long and 50 percent worn Calcarina and
detrital CaCOj. Roots abundant, as much
as one-fourth of an inch in diameter. Thick-
ness, 11 in.

GOC-2D. Strongly indurated flesh-colored
granule sandstone, of varied detrital CaCOj.
One loose sand layer 2-4 in. from base. Roots
very rare. Thickness, 15 in.

GOC-2E. Very fine grained flesh-colored
detrital limesand. No roots. Thickness,
6 in.

GOC-2F. Zone of Hcliopora. Essentially
same as fl 1643 (GOC-1E). No roots. Reef
flat horizon? Thickness, 51 in.

GOC-3. Southern part of northern main
island, about 870 ft S. 3° E. (true) from east
(inshore) end of lagoon-side jetty at Govern-
ment Station and 340 ft inshore from lagoon
beach along line bearing N. 87° E. through
Pacific Science Board campsite strip. Pit
similar to GOC-1 and GOC-2. Pit section
in descending order, with unit thicknesses, is:

GOC-3A. Dark-brownish-gray organically en-
riched limesand similar to fll644 (GOC-2A).
Roots common. Top 8 in.

GOC-3B. Similar to fll650 (GOC-3A) but
with less organic matter and only dark-tan
to light-brown color. Roots abundant as
much as one-half of an inch in diameter.
Subsoil. Thickness, 6 in.

GOC-3C. Medium-grained flesh-colored (pink-
ish-tan) limesand with occasional granules
and small pebbles (to one-half of an inch in
diameter). Mostly 90 percent worn and
smooth Calcarina but with occasional Foram-
inifera of other sorts, echinoid spines, algal
fragments, small mollusks, and detrital
CaCOj. Many roots, upper part. Thick-
ness, 38 in.

174

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

U.S.O.S. toe.
No.

111652.

None.

111653.

None.

None,
f 11654-111655.

01654.

01655.

01656.

01657-01659.

01657.

01658.

01659.

yield localities and dneripiioni

G0C-3D. Similar to G0C-3C but has fairly
numerous pebbles (one-lmlf of an inch maxi-
mum diameter) and granules; small gastro-
pods relatively common, and Marginopora
common. Thickness, 20 in.

G0C-3K. Pinkish-gray granule gravel of
fragmentary ramose calcareous algae with
interstitial Calcarina sand (worn smooth).
Thickness, 10 in.

G0C-3F. Similar to 01652 (G0C-3D).

Thickness, 40 in.

G0C-3G. Zone of large head-forming crustose
corallines and occasional astraciform corals
and interstitial sand like 01652 (GOC-3D)
and 01653 (G0C-3F). Only algae and
corals sampled. Thickness, 8 in.

GOC-3H. Similar to 01652 (G0C-3D) and
01653 (G0C-3F). (Field observation, no
sample taken.) Thickness, 8 in.

GOC-4. North-central part of northern main
island, about 1,000 ft east-northeast from
Taneang-Tckawa Maneaba. Section in area
of fine clastic limesand that makes fine-
grained loamy soil — at this place dry. Pit
section in descending order, with unit thick-
nesses, is;

G0C-4A. Very fine grained brownish-gray
(from organic matter) limesand; grades down
to f 11655 (G0C-4B). Roots common, as
much as five-eighths of an inch in diameter.
Top 10 in.

G0C-4B. Pinkish-yellow clastic limesand —
mostly fine grained, with <10 percent
Calcarina but local patches contain abundant
Calcarina. Only occasional roots in upper
part. Thickness, 26 in.

GOC-5. North-central part of northern main
island, about 1,700 ft northeast from Tanc-
ang-Tekawa Maneaba. Area of pebble coral
gravel with interstitial limesands. Stonv
and hard to dig. Dug down only 20 in., of
which top 10 in. is organic-rich, brownish-
gray soil with plentiful roots. Lower 10 in.
pinkish yellow.

GOC-6. North-central part of northern main
island, about 2,400 ft north-northeast from
Taneang-Tekawa Maneaba. Section in area
of fine clastic limesands locally with thin
gravel veneer at surface and locally of old
dune sand material near shore. Pit section
in descending order, with unit thicknesses,
is:

G0C-6A. Organic-rich, dark-gray-brown lime-
sand, 20 ± percent worn Calcarina, few smull
pebbles (as much as one-half of an inch in
diameter), many small roots. Top 6 in.

GOC-6B. Dark-tan limesand, 30-40 percent
worn Calcarina, many roots as much as one-
half of an inch in diameter; no pebbles.
Thickness, 10 in.

GOC-6C. Flesh-colored medium-grained lime-
sand, 10-25 percent badly worn Calcarina.
Thickness, 14 in.

U.S.O.S. toe.
No.

f 1 1660— fl 1661.

f 11860.

fneei.

f 11662.

fll663-f 11664.

f 11663.
f 11664.

None,
f 11665.

f 11666.

f 11667.

f 11668.

Field localities and descriptions

GOC-17. Central part of northern main
island, about 2,100-2,200 ft due east from
Buariki Maneaba. Area of fine clastic limesilt
on which water lies close to surface, hard-
pan tends to form, ground water is brackish,
and soil is generally poor. Pit section in
descending order, with unit thick-ncsses, is:

G0C-17A. Fine medium-grayish-tan limesand
and limesilt. Many roots as much as three-
eighths of an inch in diameter. Few Cal-
carina. Top 9 in.

GOC-17B. Light-tan medium-grained lime-
sand, 10-15 percent Calcarina. Roots main-
ly in top inch or two but some to bottom.
Thickness, 15 in.

GOC-19. Beach sand on the northwest shore
of islet of Nanntabuariki. Excellently pre-
served Baculogypsina and Marginopora
washed in from adjacent reef flats to north
and east.

GOC-20. Southern main island, section above
beach just south of Otoae village Maneaba,
lagoon shore. Section in descending order,
with unit thicknesses, is:

GOC-20A. Limesand, 20 ± percent Calcarina,
scattered pebbles as much as 2 in long. Top
24 in.

GOC-20B. Shell bed, limesand (50 percent
Calcarina) matrix — small Cardium most
abundant. Goes laterally to a pebble gravel.
Thickness, 6 in.

GOC-20C. Limesand, 40-50 percent Calcar-
ina, occasional pebbles as much as 2 in long.
Thickness, 15 in.

GOC-27. About 9,200 ft 8. 72° W. from off-
shore end of Government Station jetty (on
southern part of northern main island) just
south of main passage out of lagoon (Rawa
ni Karoro) where coral shoals known as Aon
te Rabata begin to deepen. Collection from
area where reef knolls and patches rise above
the limesand bottom at 16 ft depth. Most
specimens from a low coral patch about 14
ft below the surface.

GOC-28. Slightly less than 4 miles N. 85° W.
from Aiaki Maneaba in outer lagoon. Reef
patches and knolls rising above limesand
bottom (at 14 ft) to within 6 ft of water
surface. Fish taken from on and near reef
knolls and sediment taken from bottom.

GOC-29. About 1 mile 8. 32° W. from Tekawa
church at lagoon margin of south end of reef
stretch known as Aon te Baba. Collection
from reef patches rising above limesand
bottom (at a depth of 9 ft reducod to mean
low tide) to within 1 ft of surface. Much
Halimcda, many sheetlike crustose corallines
red on under sides. Limesand very fine to
limesilt at centers of open areas.

GOC-30. Heliopora flat at south end of the
northern main island. At +1 ft low tide,
tops of living Heliopora and few Porilcs lobala
seen were just flush with water surface.

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

175

v.s.a.s. lot

No.

fl 1660.
fl 1670.

f 11671-111672.

f 1 1671.
111672.

111672-111674.

111673.

111674.

111675.

111676.

111677.

11 1678.

Field localities and description t

GOC-31. Southeast end ol northern main
island. Scrapings Iroin green algal crust
on inner flat ol windward reel about midway
out (east) on reel flat Irom center ol cove at
southeast end of island. Sediment-binding
green algae are matted with Haculoyyptina,
Marginopora, and other Foraminilcra.

GOC-33. About 7,100 It S. 50° W. Irom
Tekawa church at seaward edge ol Aon te
Baba reel north ol main boat passage. Reel
area is broad and irregular, Ironted seaward
by area ol limesand 18 It deep at midtide or
about 15 It reduced to meuu low tide. (At
collecting locality reel itsell at general depth
ol 3 It at mean low tide, with holes to depth
ol 8 It at mean low tide.) Medium-grained
limesand with ripple marks parallel to reel
Iront. Slopes gradually seaward with off-
lying reel patches.

GOC-35. About 8.600 It N. 18° W. Irom
Tabuarorae Muncaba in 17 It ol water at
mean low tide.

GOC-35a. South bottom sample.

GOC-351). North bottom sample. Area ol
many coral patches on limesand-gravel
bottom. Anchored lor first sample (111671
GOC-35u) ol limesand-gravel over an area
richly floored with red bushy crustose coral-
lines, but dragged anchor and drilted north-
west about 100 yd where collected second
bottom sample (111672, GOC-35b) ol rela-
tively pure limesand.

GOC-36. Southeast end ol reel area known us
Rakai Ati (south side ol big westward point
ol reel near center ol atoll). A flourishing
reel; collection Irom reel flat northeastward
in shoal waters, Irom strip about one-hall ol
a mile long running clear across the reel.

GOC-36a. Seaward or southwestward ±600
It is area ol much coral in small and large
patches with interspersed coarse limesand
having a considerable gravel traction ol
granule and pebble size.

GOC-36b. Lagoonward or northeastward
±500 It is mostly Band with scattered coral
patches.

GOC-37. About one-third ol the distance
between the north point ol the reel area
known as Rakai Ati and the east end ol
Rakai Maneku, at inner part ol point ol reel
that projects westward Irom near the center
ol Onotoa Atoll. Sediment sample taken Irom
hole about 10-12 It deep.

GOC-38. I-ower beach at southwest corner ol
Tebaki, north end ol northern main island.
Sandy lugoon beach.

GOC-45. Area ol Thalassia patches on coarse
limesand bottom off northwest end ol outer
rib ol elevated beachrock at north Tekawa,
northwest Onotoa Atoll.

GOC-48. About 10,000 It S. 62° W. Irom
lagoon end ol Government Station jetty at

V.s.a.s. loe.
No,

111679.

111680.

111681.

111682.

111683

111684.

111685,

Field localities and descriptions

north end ol reely shoal area known as Aon
tc Uabnta. Coral patches rising to within
5 It ol surlace Irom lesser (30-50 percent ol
area) intervening areas ol limesand bottom,
12 It.

GOC-49. About 12,000 It S. 63° W. Irom
lagoon end ol Government Station jetty, on
the seaward side ol the north end of a reely
shoal area known as Aon tc Rabata, in patch
reels rising to within 6 It ol surlace Lime-
sand bottom at 18 It deep.

GOC-51. About miles N. 31° W. Irom
Tabuarorae Muncaba near center ol Te
ltawa ni Buo, a puss in south purt ol leeward
reel. Collected lrotn thickly set coral masses
rising Irom 15 It (sounded at low tide) ol
water to within about 8-10 It ol surlace
locally. Bottom ol coral-algal rock anr
living corals and algae with minor pockets ol
very coarse limesand and calcareous gravel.
Sediment sample taken in shoal area lagoon-
ward in about 3 It ol water Irom hole con-
taining course limtsAnd and gravel.

GOC-52. About 12,000 It N. 30° W. Irom
Tabuarorae Maneaba at south end ol Rakai
ni Make, a reel area in southern part ol
leeward reel. Collected corals, algae, mol-
lusks, and sample ol coarse limesand and
gravel, the latter Irom a hole in about 3 It
ol water.

GOC-53. About 9.300 It N. 30° W. lrotn
Tabuarorae Maneaba in southern part ol
Te Ruwa Tckutobibi, a pass through south
end ol leeward reel. Collected lrotn coral
patches and knolls rising to occasional maxi-
mum ol within 4 It ol surlace Irom a bottom
sounded at 18 It.

GOC-55. About 13,400 It S. 75° W. Irom
Aiaki Maneaba in deep central part ol the
lugoon. Impalpably fine limemud lrotn

bottom of low scattered dead and living
coral patches on intervening limemud and
limesand about 30-40 percent sediments and
60-70 percent coral.

GOC-56. About 8,300 It S. 76° W. Irom
Aiaki Maneaba on reel patch in the central
lagoon. Complex mass ol living coral

with patches ol limesand and fine gravel on
surlace, perhaps 150-200 yd in diameter,
rising lrotn surrounding bottom of ±18 It.
Depths on knoll 4-10 It at mean low tide,
with coral heads rising to within 1 It ol
surlace. Sediment sample lrotn mean low-
tide depth ol ±6 It.

GOC-57. About 7,500 It S. 80° W. Irom
Aiaki Maneaba on reel patch in central
lugoon. Habitat, bottom types, and depth
range similar to 111684 (GOC-56), but much
more limesand and less coral. Depth of
sediment sample at ±6 It at mean low tide
datum.

176

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Field location* and detaiptiont

GOC-58. About 3,600 ft S. 80° W. from
Aiaki Mancaba on reef patch in central
lagoon. Generally similar to f 11684 (GOC-
56) and f 11685 (GOC-57) but smaller and
deeper und contains even less coral than
f 11685 (GOC-57). Bottom at ±10 ft at
mean low tide datum, with patchy coral.
Collected bottom sample at 15 ft mean low-
tide datum from limesand slope leading off
to slightly deeper water.

51-L-8. Southeast end of Tabuarorae islet
corresponding to Aontebeke land area.
Weakly bonded limesand along beach.
51-I/-9. Southwest end of Mangaiu land area,
Tabuaurorae islet. Low, narrow north-
trending ridge in area of lush vegetation,
apparently most easterly of a set of older
dunesand ridges — ±500 ft long, about 60 ft
across from intertrough to intertrough. Only
one of set that seems phosphatic.

51-S-5. Central Tabuarorae islet. West end
of tidal flats encircled by islet.

51-8-6. Tabuarorae islet. Near center of
north arm of tidal flats encircled by islet.
51-8-7. About 4,400 ft N. 86° W. from
northwest corner of Abanekcnekc, sediment
taken in ubout 14 ft of water at mean low-
tide datum.

51-S-8. About 1,400 ft S. 60° W. from lagoon
end of Government Station jetty. Drag
sample of limesand bottom between sparse
dead and living coral, taken in about 9 ft of
water at mean low- tide datum.

51-8-9. About 4,200 ft S. 79° W. from lagoon
end of Government Station jetty. Fine
limesand bottom at 20 ft depth at mean low-
tide datum. Patches of growing coral
mostly to about 10-15 ft in diameter am
only 1-2 ft above bottom.

51-S-10. About 3tf miles N. 30° W. from
Tabuarorae Maneaba. From coarse- to
medium-grained limesand bottom about 10 ft
deep with coral pinnacles rising to within 6 ft
of surface.

51-S-1I, About 4.600 ft S. 65° W. from
lagoon end of Government Station jetty.
Limesand bottom of reentrant or depression
in large lagoon reef patch.

51-S-12. West side of Tebaki, northwest
Onotoa Atoll. Center of clean limesand
area between southwest ward extending lime-
sand spits.

FAUNA

A total of 168 species and varieties have been found
in the Onotoa samples. In table 1 the samples are
grouped, according to similarity of environment, in the
following categories:

1 . Area open to ocean on west (leeward side)

2. Lagoon

3. Reef areas

4. Islands along east side of atoll.

In the last category are included both modern beach
sands and material from a scries of dug pits inshore
from the sea beach. Samples from the pits are grouped
according to similarity of composition and in order
of increasing variety of species. With this arrange-
ment, the samples fall into three subdivisions: those
interpreted as beach sands, those interpreted as reef
flat sediments, and those transitional between these two
types of deposits.

As the Onotoa species are nearly all well known and
well illustrated (Cushman, Todd, and Post, 1954; Todd,
1957; Todd and Low, 1960), complete formal descrip-
tions are not included in this report and only a selected
few are illustrated. In a later section, certain species
that are not found in these three Professional Papers
are discussed and selected references included for them.

Major constituents of the Onotoa fauna are :

Amphistegina madagaacarienais d’Orbigny
liaculogypsina sphaerulata (Parker and Jones)

Calcarina tpengleri (Gmelin)

Elphidium striato-punctalum (Fichtel and Moll)

Homolrema rubrum (Lamarck)

HeUrosttgina auborbicularia d'Orbigny
Marginopora vertebralia Blainville

Besides these, the following species, although they make
up negligible amounts of the population, are found in
most of the samples except the beach sand:

Aeervulina inhaerena Schultze
Cibieidella variabilis (d'Orbigny)

Cornuspira planorbis Schultze
Cymbaioporetta bradyi (Cushman)

C. squammosa (d’Orbigny)

Elphidium advenum var. dispar Cushman
E. eriapum (Linnl)

Gaudryina ( Siphogaudryina ) rugulosa Cushman
Haddonia lorreaiensia Chapman
Neoconorbina palelliformis (Brady)

Planorbulina acervalis Brady
Pyropilua rotundalus Cushman
Quinqueloculina polygona d’Orbigny
Reuaaella aimplez (Cushman)

Rosalina candeiana d’Orbigny
Schlumbcrgcrina aheoliniformia (Brady)

Siphogenerina raphana (Parker and Jones)

Spirolina arietina (Batsch)

Spirotoculina angulata Cushman
Tretomphalua concinnua (Brady)

T. planua Cushman
Triloculina irregularia (d’Orbigny)

T. ohlonga (Montagu)

The remaining 138 species and varieties are rare for
the most part, and their occurrences are scattered or
single occurrences. Among them, however, are a few
species whose distribution shows a restricted, and pos-
sibly significant pattern.

u.s a s. lot.
No.

fl 1686.
f 11687.

n 1688.

f 11689.
f 11690.
fl 1691.

(11692.

(11693.

(11694.

(11695.

(11696.

Digitized by Google

Table l.~~ Distribution of Recent Foraminifera of Onotoa Atoll
IA indlcoun abundant: C, common: K. rant. Symbol printed in boldface Indkaiee presence of Uve specimens)

FOKAMXNIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

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Table 1 . — Distribution of Recent Foraminifera of Onotoa Atoll — Continued
| A Indicated abundant: C. common: R, rare. Symbol printed in boldface Indicates presence of live specimens]

178

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Table 1 . — Distribution of Recent Foraminijera of Onotoa Atoll — Continued
[A UullCHiM abundant; C, common; R, rare. Symbol printed in boldface Indicates presence of live specimens)

180

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

181

The species Teitularva Juliacea Heron-Alien and
Earland, with its variety oeeanica, appears to be re-
stricted to the central deeper part of the lagoon where
the bottom is covered by fine to coarse limesand between
patches of coral. Streblus beccarii (Linn6) is a large
robust form unknown in typical form in the Marshall
Islands but is found fairly commonly around Saipan
Island. At Onotoa Atoll it is present in some of the
lagoonal sediments. It probably is not a reef dweller.
The rare occurrences of Balitnnella jolium (Parker and
Jones) are all from limesand bottom in the central part
of the lagoon.

Examples of the Foraminifera typical of the limesand
bottom of the lagoon are illustrated on plate 25, figures
4-6.

In general, the Onotoa fauna shows rather close
correspondence in species composition to the faunas of
other areas of the central Pacific. Comparisons with
shallow-water faunas around Saipan, Mariana Islands,
(Todd, 1957), and inside the lagoons of four atolls
(Bikini, Kniwetok, Rongelap, and Rongerik) in the
northern Marshall Islands (Cushman, Todd, and Post,
1954) are of interest. At Saipan the material was
collected from depths mostly not greater than 38 feet —
deptlis comparable to those at Onotoa which were
mostly shallower than 20 feet. In the Marshall Islands
most of the samples came from depths greater than 60
feet. No striking differences in fauna were observed
between Saipan and Onotoa when the rarer occurrences
from each area are left out of consideration. In the
Marshall Islands, on the other hand, where the material
came from significantly greater depths than did the
Onotoa material, three species that are unknown at
Onotoa are present with more than scattered occurren-
ces. Their absence at Onotoa may signify an upper
depth limitation for them, somewhere between 20 and
60 feet. The species are Operculina ammonaides
(Gronovius), ('alcarina hispida Brady, and Anomali-
nella rostrata (Brady).

WET SAMPLES

Twenty-four of the Onotoa samples were treated
with alcohol when collected in 1951 and preserved wet
in order that distinction between living specimens and
empty tests would be possible. By this means an esti-
mate of which species actually lived in various locations
and which species may have been deposited there as
empty tests could be made.

In the spring of 1957, after approximately 0 years,
the samples were processed by staining in rose bengal
solution as described by Walton (1952, p. 58), Rela-
tively few specimens (such as of t he order of 1 percent)
gave a positive reaction to the stain. It is unknown
whether or not a 6-year interval between collection and

processing may affect the apparent live-dead ratio. To
me it seems doubtful that it had an appreciable effect
on the Onotoa samples, as the stained specimens
observed were mostly very clearly and unmistakable
stained.

On table 1, the record of live specimens is indicated
by the abundance symbol being printed in bold face.
An A or C printed in bold face does not of course mean
that the live specimens were abundant or common, but
merely that among the abundant or common specimens
were some live (stained) ones.

With the stained individuals forming so small a
percentage of the total specimens present, it is not
unreasonable to assume that evidence for these live
specimens would be frequently missed. This assump-
tion may be the explanation for the “lack” of stained
specimens of a particular species in certain samples
where unstained specimens of that species are common
to abundant. The following common to abundant
species are those of which living specimens probably
occurred but were missed in the samples studied.

Am)ihibtegina madagascariensis d’Orbigny
Baculogypsina spharrulata (Parker and Jones)

Calcarina spenglcri (Gmclin)

Cymbaloporeita bradyi (Cushman)

C. sguammosa (d’Orbigny)

Elphidium stria/o-punctatum (Fichtel and Moll)

Helerostcgina suborbicularis d’Orbigny
Marginopora vcrlebralis Blainvillo
Schlumbergcrina alveoliniformis (Brady)

Spirolina arietina (Batsch)

The assumption that specimens of the foregoing species
lived where they occur commonly to abundantly seems,
therefore, a safe one.

The two major distinctive habitats that arc recog-
nizable at Onotoa on the basis of the relative abundance
of species in the sediments are the surfaces and slopes
of reefs and the limesand bottom of the lagoon. Presence
and absence of stained specimens (that is, collected as
living individuals) of certain species in samples from
these two areas confirms the distinction between these
two habitats. The major inhabitants of reef surfaces
and the slopes adjacent to reefs seem to be (in order of
abundance) :

Calcarina spenglcri (Gmelin)
liaculogypsina sphaerulata (Parker and Jonas)

Amphislcgina madagascariensis d'Orbigny
Marginopora ecrlehralis Blainvillo
Cymbaloporeita bradyi (Cushman)

C. squammosa (d'Orbigny)

The major inhabitants of the limesand bottom of the
lagoon seem to be (in order of abundance) :

Amphislcgina madagascariensis d'Orbigny
Ihtcrostcgina suborbicularis d’Orbigny
Marginopora vcrlebralis Blainville
Spirolina arietina (Batsch)

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182

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Cymbaloporella bradyi (Cushman)

C. squamosa (d'Orbigny)

Elphidium striato-punciatum (Fichtel and Moll)

Schlumbergerina alveoUnifnrmis (Brady)

Minor inhabitants of the limesand floor include four
large arenaceous species, Valuulina davidiana Chapman,
Haddonia torresiensis Chapman, and the two large
species of Gawlnjina (Sipkogaudryina) ; a variety of
iniliolids; the pencroplids Pene.ro plis ellipticus d’Orbigny
and Sorites marginalia (Lamarck) ; several buliminids
including Reussella simplex (Cushman) and a few
species of Rolirina; a few discorbids including several
species of Rosaline and Neoconorbina; several species of
Elphidium; a few forms belonging in the Cymbalo-
poridae ( Pyropilus rotundatus Cushman and two species
of Tret omphalus)] and several species of the families
Anomalinidae and Planorbulinidae that are usually
attached forms.

In addition, the following species arc present as live
specimens in the lagoon but seem to be locally restricted,
their local restriction being obvious from the limited
distribution of their empty tests as well as of stained
specimens :

Buliminoides wiltiamsonianus (Brady)

Cassidulina minula Cushman

Epislomaroides polyslomelloides (Parker and Jones)

Epistaminella tubuli/era (Heron-Alien and Earland)

Placopsilina? sp.

Poroeponidcs cribrorepandus Asano aud Uchio
Siphoninoidcs echinalus (Brady)

Spirillina (several species)

Slreblus beccarii (Linin')

Tatularia dupla Todd

T. foliacea Heron-Alien and Karland

T. foliacea var. oceanica Cushman

As for the remaining 76 species present in the 24 wet
samples, for which no evidence of living specimens was
found, with but two exceptions the species are rare
with scattered occurrences. One interpretation of these
76 may be that the specimens did not live precise!}'
where found and the empty tests were deposited there
after having been washed in from another, probably
nearby, location. However, the possibility of missing
stained specimens, in assemblages where the species
in question occurs rarely, is very great. Thus a second
interpretation is that evidence of live specimens was
missed in many of these rare occurrences.

The two exceptions where species were not rare are
Spiroloculina clara Cushman and Homotrema rubrum
(Lamarck). Specimens of Spiroloculina clara were
probably washed into their collecting localities as
empty tests. In Homotrema rubrum the red original
color of the test would preclude recognition of any red
stain if present. Furthermore, it is unlikely that
broken -ofT fragments of such permanently attached
forms as Homotrema would retain their protoplasm for

long. However, in other less firmly or less permanently
attached forms, such as Planorbulina and Acerndina,
staining proved that at least some of the detached
specimens were still alive when collected.

EXAMINATION OF FISH CONTENTS

Stomach and gut contents of 22 fishes were examined
for their Foraminifera, and mail}' species were found in
several of them (table 2). The fishes fall into five
groups as follows :

Trigger Ashes:

Nos. 2-4. Rhinecanlhus aculealus (Linnaeus)

8. R. rectangulus (Bloch and Schneider)

5-7. Balistapus undulatus (Park)

20. Melichthys bu mi a (GUnther)

Surgeon fishes:

Nos. 10. Acanthurus qahhm (Forskfil)

17. Ctenochaelus slrialus (Quoy and Gaimard)

18. C. cyanoyuttalus Randall
Parrot fishes:

Nos. 9-15. Scarus sp.

File fish:

No. 21. Cantherincs sandurichensts (Quoy and Gaimard)
Puffers:

Nos. 22, 24. Arolbron nigropunclalus (Bloch)

From Cloud’s observations in the field (written
communication July 24, 1959), the feeding habits of
these groups of fish are as follows: Trigger fishes and
surgeon fishes browse mostly on algae and coral, but
they also eat small echinoids and take in considerable
amounts of the bottom sediment. The parrot fishes
browse on algae, coral, and coral-algal rock, occasionally
breaking off large chunks. The file fishes and puffers
seem to cat mainly coral.

It can be seen from the occurrence table that a greater
variety of Foraminifera species is found in the trigger
and surgeon fishes (in which the habit of taking in
bottom sediment is present) than in those fishes that
ordinarily browse only on the various plants and ani-
mals that grow up from the lagoon floor.

In general, a larger proportion of attached forms are
found in the stomach and gut contents than are found
in the bottom sediments. In only one sample, however,
was any foraminiferal material obviously bitten off by
a fish: a large fragment of Planorbulinoides retinacu-
latus (Parker and Jones) found in one of the trigger
fishes. Probably most of the specimens were taken in
as a part of the bottom sediment incidental to the
obtaining of other food. In some samples a large
proportion of the specimens of Amphistegina still retain
their light-green color and fresh appearance, suggesting
they were living when taken in by the fish.

The composite fauna from the several fish examined
is one characteristic of shallow conditions. The most
abundant species is Amphistegina madagascariensis
d’Orbigny, which is the dominant species in most

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS
Table 2. — Occurrence of Foraminifera in stomach amt gut contents of fish from the lagoon ot Onotoa Atoll

183

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184

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

shallow waters of the tropical Pacific. The next most
abundant species is Heterostegina suborbicularis d’Or-
bigny. Abundance of these two forms is known to vary
greatly from place to place, possibly for reasons related
to gregarious habit of Foraminifcra. Likewise, their
abundance varies greatly in the stomach and gut
contents. Fish No. 15, for example, contained more
specimens of Heterostegina than of any other genus of
Foraminifera.

Miliolids are much more abundant than buliminids in
the samples under discussion. Peneroplids (except for
Marginopora vertebralis Blainville, a species that appears
to live more abundantly on the reef flats than on the
bottom of the lagoon) are rare, and arenaceous forms
are almost completely missing. Globigerinids arc also
very rare in the stomach and gut contents. Quite a
large proportion of the specimens found in the stomach
and gut contents are attached forms, such as Neo-
conorbina, liosalina, Cymbaloporetta, Cibacides, Cibi-
cidella, Acervulina, Plamrbulina, Planorbulinoides, and
Homotrema.

In the bottom sediments, specimens of Tretomphalus
are found in fair abundance; those with float chambers
accompanied by rather large numbers of the Rosalina-
stages without float chambers. The morphogenetic
relationship between these two forms was demonstrated
and clearly illustrated by Myers ( 1 943, pi. 3), who also
presented other observations regarding the biology and
ecology of the genus Tretomphalus. Myers concluded
(1943, p. 21) that the planktonic stage of Tretomphalus
was very brief and lasted usually no more than 18 hours
unless the specimen became encrusted with minute
algae or other organisms, in which case it would remain
afloat indefinitely. If not thus supported, a planktonic
specimen would promptly sink to the bottom after the
escape of the gametes through the large pores in the
spherical float chamber. Thus in a tropical environ-
ment where there is no marked seasonal temperature
fluctuation and where the water temperature of about
29° C is well above the 18° C observed to be the mini-
mum temperature for development of the floating stages
of Tretomphalus (Myers, 1943, p. 22), a steady supply
of the fragile specimens with float chambers might be
expected to be constantly added to the bottom
sediments.

The Rosalina stages of Tretomphalus, however, pre-
sumably did not live in the bottom sands or muds but
attached to algae or any sort of stemmed structure and
thus could have been obtained by the fish as it browsed.
Nevertheless, most of both forms of this genus were
probably taken in as a part of the bottom sediment
rather than in the process of browsing on algae or coral
(Cloud, 1952, p. 26; 1959, p. 398-399, pis. 130, 131).

The trigger and surgeon fishes, most of which contain

a large proportion of reef-dwelling Foraminifera, such
as Baculogypsina, Calcarina, and Marginopora, may be
interpreted as being frequenters of reef flats and reef
fronts. Other fishes, whose stomachs are free or nearly
free of those large genera, probably fed mostly in patch
reefs and sandy areas. The observation that certain
fish had consumed large proportions of one or the other,
but usually not both, of the two major genera ( Cal-
carina and Baculogypsina) that inhabit the reef flats
suggests that individual fish may be quite restricted
in their food-gathering travels.

Study of stomach and gut contents of sedentary
animals might throw additional light on the probable
dwelling places of various species of Foraminifera,
whether on algae of various kinds, or on coral, or in
the sands or muds of the lagoon bottom.

Table 2 gives the species of Foraminifera found in
the 22 samples of fish stomach and gut contents. In
only three samples were species found in the fish that
were not also found in the bottom sediments:

1 . Clamlina multicamerata Chapman in fish No. 2.

It differs from C. angularis d’Orbigny in a
rounded cross section toward the apertural end
instead of a triangular section throughout.

2. Triloculina terquemiana (Brady) in fish No. 3.

3. Rosalina rugosa d’Orbigny in fish No. 2. It differs

from R. candeiana d’Orbigny in having very
coarse perforations, which may prove to be not
a specific distinction.

FORAMINIFERA FROM PITS

Samples were examined from seven pit sections well
away from the beach. All the pits were shallow, three
in the southern part and four in the central part of the
northern main island. (See USGS Iocs, fl 1 639— fl 1661.)
None of the four pits (GOO-4, GOC-5, GOC-6, and
GOC-17) in the central part of the island exceeded 3
feet in depth. The other three pits (GOC-1, GOC-2,
and GOC-3) were deeper: about 6 feet, 9 feet, and 1 1
feet, the deepest sample studied from the last hole,
however, being at 10 feet.

Omitting the pit at GOC-17, all the excavations
started in soil composed of nearly pure Calcarina sand,
much darkened by organic matter, and in which roots
were common. Some, but not all, of the specimens of
('alcanna were much worn, presumably by abrasion
before final deposition. The specimens also show the
effects of corrosion by organic acids in the soil, in that
many of the shells are porous with openings into the
chamber cavities (pi. 25, fig. 7). The dark stain and
porosity of the shells was not observed in material
obtained from below a depth of about 1 foot.

The uppermost sections of the pits at GOC-1,
GOC-2, and GOC-4 and the entire section of the pits

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

185

at GOC-3, GOO-5, and GOC-6 are interpreted as
beach sands. (See fig. 41.) These sands are composed
of Calcarina with lesser amounts of Amphi.stcgina,
Marginopora, and Heterostegina. Minor elements,
such as miliolids and species of Bnlirina and Cymba/opo-
rrtla, increase with depth in pits GOG 3 and GOC-6.
In the lower sections of these pits the orange color of
the sand and good preservation of specimens is similar
to that of modern beach sands, and there is only slight
evidence of abrasion. Presumably the species in these
pits lived not far from where they were deposited.

In pits GOO-l, GOC-2, and GOC-4 the beach sands
nre gradually transitional into sediments with a much
smaller proportion of Calcarina and a greater variety
of other Foraminifera. Nevertheless, even with the
change, Calcarina remains the predominant element
to the bottom of all the pits. (See pi. 25, figs. 8, 9.)
These richer and more varied sediments are interpreted
as a reef-flat horizon which was built up to become
progressively shallower and finally to be overrun by
the sediments of an adjacent beach — sediments that
now overlie it in the pits. The transition between
beach sands and reef-flat sediment, however, occurs
at different depths in the various pits. For example,
the pit at GOC-3, although sampled to a greater depth
than any other pit, did not — even at a depth of 10
feet- - reach the rich fauna of the reef flat horizon (fig. 41).

The pit at GOC- 17 was dug through limesand and

limesilt throughout, and the entire 2-foot section is in
sediments transitional between those of a reef-flat
horizon and beach sands. No beach sands overlie the
surface at GOO-17.

In addition to the pits on the northern main island,
a small section is exposed above the beach on the
lagoon side of the southern main island at GOC-20.
Material in the 3)(-foot section is beach sand (pi. 25,
fig. 3), slightly richer and less well worn than that
occurring in the area of the pits on the northern main
island.

A few of the species found in the pits were not found
in the lagoon sediments. None of them occur more
than very rarely and all are known as Recent species:
BdcUoidina aggregate! Carter
Conicoepirillina Irochoidea Cushman
Elphidium milletti (Huron-Alien and Earland)

Ncoconorbina fruslala (Cushman)

Patellina adrena Cushman
Pegidia dubia (d’Orbigny)

Kosalina orientali s (Cushman)

Spiroloculina corrugata Cushman and Todd

Among the species found rather consistently in the
lagoon and reef sediments, the following are conspicuous
by their absence from the pits:

Baculogypsina sphacrulala (Parker and Jones)

Elphidium slriato-p unrial uni (Fichtcl and Moll)

Uaucrina involula Cushman
Spiroloculina clara Cushman
Valvulina davidiana Chapman

GOC- 1 GOC-? GOC-3 GOC-4 GOC-S GOC-6 G0C-1?

Ftnrgi 41.— Diagrammatic sections of seven dug pita on the northern main island of Onohxa Atoll. For detailed Illustrations of Foraminifera sands of OOC-1D see

pi. 25. 11*. 9; of QOC-2F, pi. 21. flg. S; QOC-6A, pi. 25. 11*. 7

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186

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

For the last four species listed it is probable that a
shallow reef-flat horizon is not the preferred habitat
(see occurrence of these species in table 1), and hence
their absence is not unexpected. For Baculogypsina
sphaendata, on the other hand, its absence in an
environment known to be its preferred habitat is
surprising and suggests the existence of some prohibi-
tive factor, as discussed in the following section.

LOCAL DISTRIBUTION OF CALCARIXA AND
BACULOGYPSINA

With but two exceptions, the more abundant species
at Onotoa seem to be distributed more or less uni-
formly, though in varying proportions depending upon
the facies. The two exceptions are ('alcanna spengleri
(Gmelin) and Baculogypsina sphaendata (Parker and
Jones). Both of these two species are believed to be
mainly reef dwellers although some live specimens
were also found in the bottom sediments adjacent to
reefs and in some beach sands (fll676, GOO-38) and
coarse shallow sediments (fUG77, GOC-45) of the
lagoon.

Figure 40 shows the 27 localities where either one
or both of these species was found to constitute a
significant part of the Foraminifcra population. Sym-
bols indicate the approximate relative abundance of
these species to each other (not to the total fauna).
In table 1 it will be observed that either or both are
present in many other samples, but less abundantly.

It may be seen that in the overall picture (’alcanna
dominates. It is present to the exclusion of Baculogyp-
sina in 11 of the localities. In only 3 localities is
Baculogypsina present alone, while in the remaining 13
localities the 2 genera are found together, though
possibly not living together. Even though live speci-
mens were found in the same sample, easy transport
over short distances by means of surf or currents leaves
the possibility open that the two genera do not occupy
precisely the same ecological niche. In general the
samples where Baculogypsina is predominant are from
localities in or near breaks in the reef and away from
land areas (pi. 25, figs. 1, 2).

I have no theories as to the reason for the separate
geographic occurrence, here and elsewhere, of these
two genera. I believe it is more than a chance distribu-
tion, and more than a result of incomplete collection of
or examination of samples. In each of the seven pits
(fl 1 639— fl 1661, GO(’-l to GOC-17) only Calcarina
was found. As two of these pits (GOO-2 and GOC-3)
afford sections of about 9 and 10 feet, respectively,
the sediments penetrated probably represent deposi-
tion over a considerable period of time. The fact that
only ('alcanna was found in all the pit samples suggests
that Baculogypsina may have been a comparatively

late comer to this atoll. However Baculogypsina is
not a late comer in the general area of the western
Pacific as is evidenced by the fact that at Bikini and
Eniwetok atolls it is found in the shallow drillings but
is not present in the Recent fauna.

NOTES ON SELECTED SPECIES
Chrysalidinella dimorpha (Brady)

Plate 22, figure 10

Chrysalidinella dimorpha (Brady). Cushman, 1945, Cushman
Lab. Foram. Research Contr., v. 21, p. 52, pi. 8, figs.
21 , 22 .

This species is characterized by its elongate and
straight-sided form. Only a single specimen was found.

Elphidium cf. E. pooyanum (d'Orbigny)

Plate 23, figure 1

Rare specimens found in several of the lagoon samples
are distinctive in having a nearly transparent wall,
uninflated test, and very short retral processes. In
these characteristics they are similar to Elphidium
poeyanum (d’Orbigny) (Cushman, 1939, p. 54, pi. 14,
figs. 25, 26), a common species of the West Indian
region. They are easily distinguishable from E. simpler
Cushman, which has an umbilical plug, a milky wall,
and a tendency toward inflation of the later chambers.
I have not observed this very transparent species
elsewhere in the western Pacific.

Qlobigerina cf. G. inflata d'Orbigny
Plate 24, figure 1

Rare specimens in the lagoon samples, mostly in
those samples from areas open to the ocean on the
southwest, seem related to Qlobigerina inflata d’Orbigny
(Cushman, 1946, p. 16, pi. 3, fig. 3; pi. 4, figs. 1-4).
They are close coiled with four chambers making up
the final whorl and have a large, arched and rimmed
aperture that opens into the umbilicus.

Qlobigerina inflata was not found in the Qlobigerina
oozes around the Marshall Islands, nor was it observed
among the rare globigorinids found in the shallow sedi-
ments around Saipan. Its nearest reported occurrence
seems to be the Mid-Pacific seamounts (Hamilton,
1953, p. 222).

Globigerinita glutinaU (Egger)

Plate 24, figure 3

Globigerinita glutinata (Egger). Pblegcr, Parker, and Peirson,
1953, Swedish Deep-Sea Exped. Repts., v. 7, Sediment
cores from the North Atlantic Ocean, no. 1, p. 16, pi. 2,
figs. 12-15.

Rare specimens of this small globigerinid occur in
the lagoon and in the area open to the ocean. One

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FORAMINIFERA FROM ONOTOA ATOLL, GILBERT ISLANDS

187

occurrence was from sediments interpreted as a reef-
flat horizon from the bottom of one of the pits.

Neoconorbina terquemi (Rzehak)

Rosalina orbicularis Terquem, 1876, Essai Classemeut Animaux
Plage Environs Dunkerque, Paris, fasc. 2, p. 75, pi. 9,
fig. 4.

Rosalina terquemi Rzehak, 1888, Austria Geol. Reichsanst.,
Verh., p. 228.

Conorbina orbicularis (Terquem). Parker, 1954, Harvard
Coll. Mus. Comp. Zoology Bull., v. Ill, no. 10, p. 522,
pi. 8, figs. 13, 14.

This species is type of the genus A T eoconorbina; the
name terquemi was proposed to differentiate Terquem’s
species from one described earlier under the name by
d’Orbigny.

The species occurs in a few of the lagoon and reef-flat
samples, in some samples fairly commonly. Their low,
flat, scalelike shape suggests they were attached in
life.

Rubeculina divaricata (Brady)

Nubeculina divaricata (Brady). Cushman, 1932, U.8. Natl.
Mus. Bull. 161, pt. 1, p. 48, pi. 11, figs. 5, 6.

This miliolid with arenaceous coating is generally
recognizable only when its uncoated tubular neck is
preserved. It was found in a few of the lagoon and reef
samples.

Placopailina bradyi Cushman and McCulloch

Placopsilina bradyi Cushman and McCulloch, 1939, Allan Han-
cock Pacific Exped., v. 6, no. 1, p. 112, pi. 12, figs. 14, 15.
Placopsilina cenomana Brady [not d'Orbignyl 1884 [part],
Challenger Rept., Zoology, v. 9, p. 315, pi. 36, fig. 1 [not
figs. 2?, 31.

Several specimens of this permanently attached form
were found on the surfaces of shells and algae from the
reef edge (f 1 1681 , GOC-52). They consist of a scries
of coarsely agglutinated chambers, initially coiled, then
in a uniserial arrangement and an irregularly winding
course.

The first mention of this species (see second reference
in synonymy) included two and possibly three types of
forms under the name Placopsilina cenomana: figure 1,
coarsely arenaceous, white, and with transverse meas-
urements of 0.30-0.45 mm ; figure 3, arenaceous, orange,
and with transverse measurements of 0.04-0.08 nun;
and figure 2 possibly differing in being either finely
arenaceous or not agglutinated. The distinction be-
tween the very small orange one and the larger white
one was recognized by the erection in 1920 of P. confusa
Cushman (1920, p. 71, pi. 14, fig. 6) for the former,
leaving the latter in P. cenomana d’Orbigny. The
original description of P. bradyi, however, included all

three of Brady’s figures in synonymy, probably by
oversight, as no mention of P. confusa is made, and the
description, figures, and a paratype in the U.S. National
Museum collection (USNM 35815) all indicate that a
form equivalent to Brady’s figure 1 (not fig. 3) is meant
to curry the name of P. bradyi.

As comparison of type material of the two species,
P. confusa and P. bradyi, indicates possible if not
probable specific differences between the two, the name
P. bradyi is retained for the Onotoa specimens.

Placopailina? sp.

Plate 22, figures 3, 4; plate 25, figure 5d

Rare fragments of irregularly curving cylindrical
agglutinated tubes, consisting of uniserial chambers
varying in height but usually quite low and uneven in
shape, were found in three lagoon samples. One un-
broken end shows a smooth, round, and unrimmed
apertural opening in the depressed center of the final
chamber. These fragments may be the upward-growing
parts of attached specimens of Placopsilina.

Quinqueloculina polygona d'Orbigny

Plate 22, figure 5

Quinqueloculino polygona d’Orbigny, 1839, »'n De la Sagra,
Histoirc physique, politique et naturellc de Pile de Cuba,
Foraminifferes, p. 198, pi. 12, figs. 21-23.

Cushman, 1932 [part], U.S. Natl. Mus. Bull. 161, pt. 1,
p. 25, pi. 6, fig. 6 [not fig. 51.

Typical specimens of this angular miliolid that was
described from shore sands of Cuba are present, some-
times abundantly, in the Onotoa samples.

Boctobolivinal sp.

Plate 22, figure 8

Rcclobolivina sp. Todd, 1957, U.S. Geol. Survoy Prof. Paper
280-H, p. 290-291 (table)

In the Onotoa material, particularly that from the
reef-flat horizons in pits GOC-1 and GOC-2, are rare
specimens that arc questionably referred to this genus.
They are identical with some from Tanapag lagoon,
Saipan. They are always in association with Sipko-
(jenerina raphana (Parker and Jones) from which they
are distinguishable by their much smaller size (0.35-
0.55 mm long), slenderer form (0.10-0.20 mm wide),
more translucent wall, proportionally longer multiserial
stage (becoming biserial but twisted in the present
material), and the slightly indented sutures and hence
slightly lobuluted outline. They may prove to be
related to Siphogenerina raphana, possibly being in-
cluded in the same species.

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188

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Rosalina candeiana d'Orbigny

Rosalind candeiana d’Orbigny, 1839, in De la Sagra, Histoire
physique, politique et naturellc de l’lle do Cuba, Forami-
niffcres, p. 97, pi. 4, figs. 2-4.

Discorbis opium Cushman, 1933, Cushman Lab. Foram. Re-
search Contr., v. 9, p. 88, pi. 9, fig. 3.

This is the commonest of the diseorbids found at
Onotoa, occurring in nearly all the lagoon samples and
on the reef flats. It is too fragile to persist in the heach
sands. As is typical of the family Discorbidae, speci-
mens were probably loosely attached by their ventral
surfaces during life, but not cemented, so that as
empty tests they were easily washed down into the
bottom sediments.

Rosalina concinna (Brady)

Discorbina concinna Brady, 1884, Challenger Uept., Zoology, v 9,
p. C4G, pi. 90, figs. 7, 8.

Discorbi * micens Cushman, 1933, Cushman Lab. Foram. Re-
search Contr., v. 9, p. 89, pi. 9, fig. 5.

This small circular scalelike species was also attached
during life. It is almost surely the early stage of the
species of Tretomphalus that is called T. concinnus
(Brady), referring to the same Brady reference as above.
Thus the separation of these two forms is wholly
artificial and a matter of convenience. In most sumples
where either is common, the two forms occur together.

Rosalina oriontalis (Cushman)

Discorbis orienlalix Cushman, 1920, B. P. Bishop Mus. Bull. 27,
p. 130 (imprint date 1925).

Todd, 1957, U.S. Cool. Survey Prof. Paper 280-H, p. 290-
291 (table), pi. 90, fig. 13.

Comparison with the types indicates that this species
is merely a high-spired form of Rosalina candeiana.

Spiroloculina rugosa Cushman and Todd

Spiroloculina rugosa Cushman and Todd, 1944, Cushman Lab.
Foram. Research Spec. Pub. 11, p. 60, pi. 9, figs. 9-13.

A single specimen of this species with its distinctively
rugose wall was observed in f 11667, GOC-29.

Spiroloculina venusta Cushman and Todd

Spiroloculina venusta Cushman and Todd, 1944, Cushman Lab.
Foram. Research Spec. Pub. 11, p. 00, pi. 8, figs. 16, 17.

This species was found rarely in the lagoon samples.

Svratkina sp.

Rpistominella sp. D, Todd, 1957, U.S. Geol. Survey Prof. Paper
280-H, p. 292-293 (table), pi. 92, fig. 2.

Svratkina sp. A, Todd and Low, 1900, U.S. Geol. Survey Prof.
Paper 260-X, p. 840.

The genus Svratkina was erected (Pokorn£, 1956, p.
257) for specimens that had been previously reported
under various other names from Australia, Europe,

and America and from the Eocene (if not older) to the
Recent. This compact and close-coiled genus is dis-
tinguished by large pores, particularly on the dorsal
side, the pores sometimes surrounded by tubular necks,
and by the aperture being a long, narrow opening ex-
tending from the umbilicus along the base of the
apertural face to a depression beneath the periphery
where it widens and extends upward into the apertural
face.

The first reference cited above is to specimens of this
genus from Recent lagoon sediments of Saipan; the
second to specimens from the upper part of the Eniwe-
tok drill holes in the Marshall Islands. Identical speci-
mens are found rarely at Onotoa. They seem very
close to the type of the genus, Discorbis tuberculata
(Balkwill and Wright) var. a ustraliensis Chapman,
Parr, and Collins, but may prove to be distinct when
sufficient material becomes available.

REFERENCES CITED

Cloud, P. E., Jr., 1952, Preliminary report on geology and murine
environments of Onotoa Atoll, Gilbert Islands: Natl. Acad.
Sci., Natl. Research Council, Pacific Sci. Board, Atoll Re-
search Bull. 12, p. 1-73, figs. 1-8.

1959, Geology of Saipan, Mariana Islands. Part 4,

Submarine topography and shoal-water ecology: U.S. Geol.
Survey Prof. Paper 280-K, p. 361-445, pis. 2, 120-139,
figs. 36-43.

Cushman, J. A., 1920, The Foraminifera of the Atlantic Ocean.
Part 2, Lituolidae: U.S. Natl. Mus. Bull. 104, pt. 2, p. 1-
111, pis. 1-18.

1939, A monograph of the foraminiferal family Non-

ionidae: U.S. Geol. Survey Prof. Paper 191, p. 1-100, pis.

1 - 20 .

1946, The species of Globigerina described between 1839

and 1850: Cushman Lab. Foram. Research Contr., v. 22,
p. 15-21, pis. 3, 4.

Cushman, J. A., Todd, Ruth, and Post, R. .1., 1954, Recent
Foraminifera of the Marshall Islands: U.S. Geol. Survey
Prof. Paper 260-11, p. 319- 384, pis. 82-93, figs 116-118.
Hamilton, E. L., 1953, Upper Cretaceous, Tertiary, and Recent
planktonic Foraminifera from Mid-Pacific flat-topped sea-
mounts: Jour. Paleontology, v. 27, p. 204-237, pis. 29-32,
figs. 1-5.

Myers, E. H., 1943, Biology, ecology, and morphogenesis of a
pelagic foruminifer: Stunford Univ. Pubs., Biol. Sci., v. 9,
no. 1, p. 1-30, pis. 1-4.

Pokorny, Vladimir, 1956, New Discorbidae (Foraminifera) from
the upper Eocene brown Pouzdfany marl, Czechoslovakia:
Prague, L'niv. Carolina, Geologies, v. 2, no. 3, p. 257-278,
figs. 1-15.

Todd, Ruth, 1957, Smaller Foraminifera, in Geology of Saipan,
Mariana Islands. Purl 3, Paleontology: U.S. Geol. Survey
Prof. Paper 280-II, p. 265 320, pis. 2, 4, 64-93, tables 1-4.
Todd, Ruth, and Low, Doris, 1960, Smaller Foraminifera from
Eniwetok drill holes: U.S. Geol. Survey Prof. Paper 260-X,
p. 799-861, pis. 255-264, text figs. 256-259, tables 1-7.
Walton, W. R., 1952, Techniques for recognition of living Foram-
inifora: Cushman Found. Foram. Research Contr., v. 3,
pt. 2, p. 56-60.

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INDEX

A Pase

Atanekenekc 170

Acanlhurut fohhm 182.183

ccertali t. Minor Ivlina 170, 100, 183

Acerrultna 182.184

inhorreru 170,181X183

5p 180

acicularit, Spirciina, . 178

Acknowledgments 171

acvUatut, RkweeaiUkn* 182. 183

adumo altiformis. Pateilina 171)

PaieUina 179.185

adzrnum ditpar, Flpbidium 170. 179. 183

Elpbidium 179

aequiloterolit, GlobifcrineUa 180

aaqlulina nt, Quinqueloculina 177

Tcrtulorta. 177

acvrrcoio, fldelloidinet 17X, |K.*»

Afakl Maneata 174. 175. 170; pi. 25

.1 Uiatina translucent. 179; pi. 23

altiformis. Patellina adrcua 179

oleeota, TertuUsxia 177

A|v*oUneHkfaw its

aheoliniformit, A mmomattllina 178

Schlumtkrqerina 170.178, 181, 182. |83

A mmobaeulHet sp 177; pi. 22

Ammomauilina alreoliniformis 178

ammonoidts. Operculina IHl

Amphittegina 182.185; pi. 25

madajatcorientit. ... 17& 179. 181, 182. 183; pi. 25

Amphisteglnldnc. 179.183

anguina arcnata, Quinqueloculino 177

angularit. Ctorutina 177.183.184

angulota, SpiraUeulina 170. 177. 183

Anomalina flabrata IKO

AnomalintUa roMrata 181

Anomallnldae. 18(1 182. 183

Aon U* Bata. 174. 175; pi. 25

Aonlebckr land turn 170

Aon U? Batata shoals 174. 175

arenata, Quinqueloculino anguina 177

unrfini, Spirolina 170. 178. 181. 183

. I rc4k ton mgropun dot ns 182.183

Aniculina elongata 178

paciflca 178

auriculata. U'iesneTella . 178

etufrffffmil. fHscorbls tutxrcvlata 188

auitrollt, .\filiolintUei 178.183

Hodilowvina 172. 174. 175c 184. 180; pi. 25

tpkaerulata 170, 179. IHl, 183. 185. 180; pi. 25

Ihlittaput undulatus 182. 183

Rdtlloidina aggregate 178. 185

Beach saints 171. 170. 185. 180; pi. 25

bttearti, Stnbltu 179. 181. 182. 183

tcpida, Streblus. 179

htrlht lotion a, Quingueloenlina 177

bicarinota. Triloculina 177

bidentola, Quingueloculina 177.183: pi. 22

Bikini atoll, Marshall Islands. 181,190

Relit ina 182.185

com pod a 179

(/yoroKomum) Umbata. 179

THafori ., . 179

rhombcidalls 179

striatula 179. 183

tut«xco9ota 179

tortuaia 179

Pol irintlla folium 178.181

Rrreli* pulekrus 178

(Italic numbers Indicate descriptions]

Page

bradgi, Cgmbaloporftta 176c 179. 181. 182. 183

Panina 178.183

Placoptilina 178 . 187

Buarlkl Maneata 174

RulimintUa milletti 178

Bullmtnldae 178,183

Ruliminoidtt teiUlamsonianut. 178.182

bulloidet. GMigerina 180

bunisa, Meliehthgt 182.183

Calcarine 172, 173. 174. 184, 185, 186; pi. 25

Kitpida 181

tpcngleri 176. 179. 181. 183, 186; pL 25

Ctfearinldtt 179.183

Carncrlnidac 178,183

candeiana. Rotalina. 170. 179, 183, 181 . 183

Tcitutoria 177,183

Cantherinet tandwiduntit 182.183

Cardlu m 174

Conutulina mtnuta 179, 182

Casitdullnidae 179

ctnomano, Placoptilina. 187

CKtgtaUdinella dimorpba 179. /#; pi. 22

CtotcUtOa 184

aarlabilit 170. ISO. 183

Cibicides 184

cicairicosvt 180

lobatulus 1801183

mafoti 180

pMfudounffcriornit 180

cioatric'sus, CibichUa. 180

claro lirata, Spirdoeutina 177

Spiroloevlina 177.182.183.185

Clatulina an gn laris 177. 183. 184

mvlticamcrata 183,184

corn mu nit, Spiroloculina 177

com pact i, Rolirina 179

concinna. Ditcorbina 188

Rosaline... 179,183./#

concinnus, 7>ctompbaJur 170. 179, 183. 188: pi. 24

confute . Placoptilina 187

conglobatus, n lobiarrinoidet 180

Conicospirillina trocKoidea 179. 185

sp ... 179, 183; pi. 23

Conorhina crbieularh 187

Carpuspita ylanorbit 170.178.183

corrugata, Spiroloculina 177.185

eribrorepandus, Porocponidct 179. 182. 183

crlspum, Rtphldium 170,179.183

Ctcnochoetu* eganoguttatus 182,183

tltlalut 182.183

euncafo, Ttihculine . 177.183

cfanoatiUottit. CltnocAartut 182,183

Cembalo pocctta 184.185

bradvi 170.179,181.182.183

tquommota . 170, 179, 181. 182, 183

CymtaloporhUn* 179.182,183

dovtdiana, laJrulina 177,182.185

dec or at a, Spirillina 179

dcnlicutata, Pyrp> 178

denticulo-eranulaia. SpMtlina 179; pi. 23

dimorpko. Ckrptalidinc/la 179. /#; pi. 22

lllfcorbldae 179.183.188

IH teat b ina concinna 188

/Htcorbit micro* 188

opima — 188

orientolis 1S<

tuWrculala auriroUmtit 188

Page

ditpar, FJphidium adaenum. 170,179.183

dirtcnjucata. Quinqucloiultna 177

Dbtribution of Calcarine and Raculofftptina,

local 186

Distribution of Recent Fommlni/em 177-100

diraricxjta, Xubcculina. 178. 137

diner to. Ifaucrma 178

dubin. Peqidia 179, 185

dupla, Talularia 177.182

earlandi. Tritoculma 177

cchinatut, -Siphoninoidet 179. 182

ewtri, Olohifcrina 180; pi. 24

etlipticus. Pencroplit 178.182.183

(Jonffata, Articulina 178

Eiphldlklac 179.183

aphidium 182

adeenum 179

ditpar 170,179.183

critpum 178, 179. 183

milUtti 179.185

poepanum 179, /Stf.p!.23

simpler 179,183.186

rtriclo-pur.rtattnn. 1701

179, 181, 182, 183. 185; pi. 25

Eniwetok atoll, Marshall Islands 181,180.188

Epittomaroldet polyttomcUoidet 179. 182

Kpittominclla tubullfaa 179.182

sp 188

Examination of fish contents 182-184

crifua, PlanitpirincJIa 178

aimia, Spiroiocvlina 177

Fauna 170-181

ferustaci, Quinquctoculina 177

Fitchaina pclludda 178; pi. 22

Fischer In I da«* 178

Fltsurina lacunata 178

latenoidet 178

ntillcU i 178

foliaceo ocean ice, Tertularia 177, 181. 152

Teriularia... 177.181,182

folium, RolMrtella 178,181

ftovdereent. Saqcnina 177

frutlata, Xtoccmorbina 179. 185

fitibm, Aeanlhurut 182.183

Gnudrpina pauperata 177,183

(•Sipkofoudryiaa) 182

ruffuloto .......... 176, 177; pi. 25

tiphoni/era

177

otabrato, Anomalina

180

(•lobifferina bulloidet

180

ttteti

ISO; pi. 24

in Hat a

1NT»

180.183

Glohiaerinita qlulinata

Globinrinoidet conolobertui . .

180

ISO. 183

saccu lifer

ISO. IM

180

ISO. IK: pi.

Government Station

. ITS. 174. ITS. ITS; pi. M

Gpptina qlohula

IN)

1*)

1*0

180

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190

INDEX

H P«'

Hnddonio torresiemii 176. ITS. 182

Ilalimeda 174

Hauerino direr i a 178

insoluta 178.183.18$

milletU 178,183

paciflca 178,183

terrain 178

speciotn.. 178

lUtiopora 173.174

Heterohellridae 178

Ifrterostegina 184. 18$: pi. 25

suborbicularii 178. 178, 181, 183. 184; pi. 25

hispido, Calcarine.. 181

Homotrema 182, 184

rubrum 17*180,182.183

Horaotremidae 180.183

Hyprramnilnidor 177

inarouolis. SpiriUina 179

indium, TrUoculina 177. 183

in (tain, Oloblgtrina 180. 18$; pi. 24

inhatreni, Acervulina 178. 180. 183

Introduction 171

invotuta, Hauerina 178, 183, 185

irregular it, 7 YUoculina 176.177,183

Islands along rut side 171,176,177-180

kcnmbaUca, TrUexulina 177,183

labiate, SfUlolintlla 178,183

facunafa, Fitiurina 178

lagenoidei, Fitiurina ...... 178

Lagoon 171, 17ft, 177-180, 181. 182, 184

Leeward tide 171. 176. 177-180

timbale, Holirin a (Loiaitomum) 170

Itrata, Spiroloculina data . . 177

Lltuolldac 177

Mata, Portia 174

lobatulus, ObMdes 18a 183

Locality data 173-176

(Lojoitomum) limbata, Holirina 170

mayori, Hoi trine 170

madagascarientit, A mphhtegina 176,

170.181.182. 183; pi. 25

Mangaia land area 176

marginahs, Sorties 178, 182

Marginopora 173. 174, 176. 184. 186; pi. 25

StrUbrah* 176.178,181.183.184

Mariana Island* 181

Marshall Islands 181. 186. 188

marakallana, TrUoculina 177

MattUina pianola . ... 177

Material studied 171

mayori, Holirina (Loxotlomum) 170

CWcida 180

Melichlhyt tiunira 182, 183

mlcem, JHtcorbii 188

Mld*Padflc seamounts. 1W»

Millolldaa 177.178,183

MihclineUa austroli s 17$. 183

lahiota 178.183

oceanica 178

miUetti. HulimineUa 178

Etphidium 170.185

Fitiurina 17H

H'iurtina 178,183

minuta, Cdufdulina 170.182

Monvlptidiun polUum. 178

muliieanurala, Clavulina . 163,184

Nanntabuarlkf Islet 174; pi. 25

Neocenorbina . 182.184,187

fruKata 170.185

pateUiformis 176.179.183

terguemi 170 , 187

tuberocoptiala 170

nnrtriatula, Qulnfutlanlha

niffropunaatu,. .lr«Aron.

Pace
177.183

Xonion pacificum .. .

Xonlonella sp

179

Xonlontdai?

Notra on wlectwl sihtIcs . ...

Xubeculina divaricate

i7R iter

obUguiloculata, PuUenialina 180; pi. 24

cMonta. TrUoculina 178,177.183

occanica, \filioHncHa 178

181

Ophthalmldlidoc

opima, Ditcotbit

orbicularii, Conor bine

187

Ho ml hi a

Orbulina untrersa

oriental is, DiicorbU : . . .

Hatch na

Otoae village Maneaba

Pacific Science Board campsite 173; pi. 26

pacifica, Arttiutina 178

llauerina 178, 183

pcei/lcwm. Xonton 170

papiUUa, Sphatridia 170

Panina brodyl 178, 183

paitUiformli. Xeoconorbino 176,170.183

PateUino adscnc 170,185

adeena all i/or mil 170

pauperota. Oaudryina 177,163

Ptgidia dttbia 170.185

Pcgldllda* 170

ptUucida, Fitcherina 178, pi. 22

PeneropUdac 178,183

Penerophs cUipticus 178, 182, 183

profit!* 178,183; pi. 22

Pitts, Koramlnlfera from 171,

176. 177-180, 184-186; pi. 25

Placopsthno 187

bradyi 178 .187

ccnomcna.. 187

confuto 187

sp 178, 182. 187. pis. 2/, 25

Placopsillnldac 178

plana, Of pt i no... 180

pianola, MattUina. 177

PlanitpirineUa talguo. 178

planorbit, Camutpita 176, 178. 163

Ptanorbulino 182,184

arerpalis 17ft. 180. 183

rubra 180

Plonorhulintdac 180. 182. 163

Planorbuliaoidet IK4

utinaculatui 180. 182. 183

planus. Tretompbaltu 176, 179. 183; pi. 24

poeganum, Flphidiu m 170, 18fi; pi. 23

pofifum, Monalytidium. 178

polygona. Quingueloculrne 176. 177, 187 ; pi. 22

Polymorphlnidoc 178

polyitomellcidet, Kpisiomnroidti 170.182

Parkes lobata. 174

Poroeponidet nibrortpandus ... 170,182.183

porr<cfa, Vvigerina 170

prole ui, Pentroplii 178, 183; pi. 22

prrMdauncrrianu*. Cibieidrt 180

pulchrut, Pot el is 178

PuUeniUina oMiguiloevlola 1W; pi. 24

Pyrgo dentieulala 178

r*yropilut rdundalut 176. 170, 182; pi. 22

Qu trig velocv Una agglutinovs 177

ongufna arena/a 177

bcrthclotiana 177

bidenlota 177. 183; pi. 22

Quingueloculina Continued Pair®

dittorgueaia 177

/trussed 177

veostriat ula . 177.183

polygene 176. 177. 187; pi. 23

lulcoio 177.163

tubus 177

Mani'ku

175

ni Make

ropkona, Sipkotrn^M

... 176, 179. 183. 187

Rnwa ni Karoro..

reetangului, Hhinecanthus

182.183

. 170. 1H3. IN?: nl. 22

Reef areas 171. 176, !77-18a 181. 184. 165

188

ntinaculatus, Planorbulinoidet . . .

... 176u 170. 182. 183

rerertent, SpiriUina riripara

182. 183

rtrtonfU/tL,

170

179

Rongelap atoll. Marshall Islands

181

Rongrrik atoll. Marshal) Islands

181

176. 170. 183. 184. 188

candnna

orbicularis

170. 185. m

rugose

terguemi

167

18!

170.183

rotnndoint, l*yropUus

. 176.170.182; pi. 22

180.183

... 176. ISO. 182. 183

183. 184

Spiroiofutino

rugulo *o. (laudrylna (Sipkogaudryina) 176, 177; pi. 25
8

lacculifer, <>lobi;erinoida 18a 163

Sigm inn frondneens 177

Saipan Island................ 181, 186. 187. 188

sandwiehentit. Cantherina . .. 182,183

Scar vt sp... 182.183

SdUumbergerino alstohni/ormis 176,178,181,182.183

i err ala, Ifouerina 178

Sigmomorphina terguemiana 178

timppi. Rphldtum 170.1S3.186

HeusteUa 176,170.182.183

(,SipAo?audrjrina), laudryina 182

r hq vloia, Oattdryfna. ............. 176, 177; pi. 25

liphonifera. Ooudryino ., 177

.NipAocinirfna raphana. . 176. 170. 183. 187

tipboni/fra. Gaudtyina (Sif>hoQ 0 udrylnai 177

SlpKonina tubulooa 170

Siptoninoidii cdiinatu* 170.182

Sortie j marginal li 178, 182

Southern part of atoll 171. 177-160

i pec iota, llauerina. 17H

ipmaleri, Colcarlna 176c 179. 181. 183. 186; pi. 25

Spbaeridia papillate 179

jpAomi/afa. Haculogyptina. ...176, 170, 181, 183, 185,
186; pi. 25

spinata, Tyilocvlina — ............... — .... 177

SpiriUina 182

decorate 170

denticulogranulata 170. pi. 23

inaeaualU — 170

l«6rrciitofo-Bmftafa 170

riripara . . - 170.183

rererteni — 179

Splrllllnidftc 179.183

Spirotina acievlarU — 178

arietina 17^178.181.183

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INDEX

191

itpirolotuilaa angu/ato

Ptf«

mm. 163

tngutmi, tooconorbina

187

litata

terguemhno. Stgmomorpkina

178

177

TrUoeulina

177.185

Tcxtularia agglullnans

177

ejimla

olxtaia

177./**

177.183

rtauita

177. tSS

duple

179. 181. 182. 183

177,181.182

btcearit tepida

179

.. 177, 183

atrUxto-pundaMm, KtpMdium.

..178. 179, 181, 182,

lliataana

1S3. lM.pl 25

torrtjie niit, Ifaddonla

176.178.182

182.183

suborbtculnru, HeUrostcgino

176, 178. 181, 183. 184;

7>etomphalM

pi. 25

concinn us

17$. 179. 183. 188; pi. 24

tuhiilanciana, Trilotulma

pta itui

auleata . QuinQueloculina

177.183

177

Saralkina $p

ttigonula, TriloeuUna

Trilaculma bieminata

17$; pi. 25

177,183

174.pl. 25

177.183

Tcbakl

irttguUttia .

175

177.183

174. 175; pi. 25

177

tepida, StreNua b«carii

179

obtonga

178; 177. 183

To Raw a nl Bao

175

xptnata

177

TV Raws TVkatobJbl

tubnlanciana

7V<teci<Rno —Continued Pa*e

tavutmla na 183, 134

InnitmatTiaU 177

trlcarluala 177

triconula . . 177,183

troth ten, ConlcotpiriUlna 179. 185

tulxreutata auXraUmi), DUtorblt 188

tubtrculotoJimbato, Spirillino 179

tubtrotapitoto, AVoconwMna 179

tuhult/rra. EptHomlhtlla 179, 182

fuAtifo», Siphmina .. 179

tub tu, Qutnfttrjocvttna 177

undulatat, Hallttapui 182,183

unrrfrjti, Orbulina ...... 180; pi. 24

Vtiftrina porretta 179

Vatnilina dantlana 177,182.183

Vulvullntdae 177,183

eerlaftUU, CUMitUo 178. ISO. 183

era urto. Spiroioculina 177. 188

Vemeulllnldae 177.183

nrtthtuUt, bfarfinopertt 178. 178, 181. 183. 184

ratcularU. Oypjino ISO

rirtpora rtrtrltni, SpirtlUna 179

SpirilliM 179,183

Wet samples 181-182

H’teenrreifo enriculalo,.... 178

■rUlfanutmtoniu, BuUmtnotia 178. 182

Windward side 171

l). s. COVKHNMKNT PMIVT1KC OKKK-'K ; ISM O - S5JSM

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PLATES 22-25

PLATE 22

Figure 1. Ammobaculites sp. (p. 177 tab.)

USNM 626873, X 56; USGS fl 1667, GOC-29.

2. Quingueloctdina bidentata d'Orbignv. (p. 177 tab.)

USNM 626883, X 44; USGS f 1 1G79, GOC-49; a, side view; b, apertural view.

3, 4. Placopsilinat sp. (p. 187)

3. USNM 626879, X 27; USGS fl 1678, GOC— 18; a, 6, opposite sides; 6, attached surface; e, edge view showing terminal
aperture.

4. USNM 626880, X 27; USGS f 11678, GOC— 18. Fragment of a terminal part that grew outward from initial
attached portion.

5. Quingueloculina polygona d'Orbigny. (p. 187)

USNM 626888, X 44; USGS f 11683, GOC-55; a, side view; b, apertural view.

6. Pischerina pellucida Millett. (p. 178 tab.)

USNM 626874, X 40; USGS f 11667, GOC-29.

7. Peneroplit proleus d’Orbigny. (p. 178 tab.)

USNM 626875, X 93; USGS f 11667, GOC-29.

8. Reclobolivinal Bp. (p. 187)

USNM 626872, X 140; USGS fl 1049, GOC-2F; a, side view; ft, top view.

9. Pyropilut rotundatus Cushman, (p. 179 tab.)

USNM 626889, X 56; USGS f 1 1 684, GOC-56; a, dorsal view; ft, ventral view; c, peripheral view.

10. ChrysalidineUa dirnorpha (Brady), (p. 186)

USNM 626890, X 88; USGS f 11690, 51-S-6; a, side view; ft, top view.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 354 PLATE 22

RECENT BENTHON1C FORAMINIFERA FROM ONOTOA ATOLL

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PLATE 23

(a. Dorsal view; b. ventral view; e, peripheral view, except u Indicated]

Figure 1. Elphidium c(. E. poeyanum (d’Orbigny). (p. 186)

USNM 626876, X 93; USGS ft 1 667, GOC-29; a, side view; b, peripheral view.
2. AUiatina Irantiuctnt (Cushman.) (p. 179 tab.)

USNM 626886, X 140; USGS (11679, GOC-49; a, side view; 6, peripheral view.
3, 4. ConicospiriUina sp. (p. 179 tab.)

3. USNM 626871, X 180; USGSfll687, GOC-29.

4. USNM 626870, X 220; USGS f 11667, GOC-29.

5. SpiriUina denticulo-granulala Chapman, (p. 179 tab.)

USNM 626881, X 93; USGS f 11679, GOC-49.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 3M PLATE 23

RECENT BENTHONIC FORA M 1 N I FERA FROM ONOTOA ATOLL

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PLATE 24

[a, Dorsal view; 6. ventral view; c. peripheral vlcwj

Fioube 1. Globigerina cf. G. in flat a d'Orbigny. (p. 186)

USNM 626887, X 93; USGS fU679, GOC-49.

2. Orbulina universa d'Orbigny? (p. 180 tab.)

USNM 626891, X 112; USGS 111691, 51-S-7.

3. Globigerinila glulinala (Kgger). (p. 186)

USNM 626877, X 194; USGS 111667, GOC-29.

4. Trelomphalua concinnua (Brady), (p. 179 tab.)

USNM 626885, X 93; USGS 111679, GOC-49. Side view.

5. Globigerina eggeri Rhumbler. (p. 180 tab.)

USNM 626878, X 112; USGS 111670, GOC-33.

6. Trelomphalua planua Cushman, (p. 179 tab.)

U8NM 626884, X 70; USGS 111679, GOC-49. Side view.

7. PuUenialina obliquiloculata (Parker and Jonea). (p. 180 tab.)

USNM 626882, X 70; USGS 111679, GOC-49.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER S>4 PLATE 24

RECENT PLANKTONIC FORA M 1 N I FERA FROM ONOTOA ATOLL

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PLATE 25

[All flgurps X 15)

Figure 1.
2 .

8 .

Daculogypsina sand from islet of Xanntabuariki on windward (northeast) side of Onotoa Atoll. USGS fl 1662, GOC-19.
Fresh specimens washed onto beach from adjacent reef flat.

Haculogypsina sand from southeast end of Tabuarorae islet, south end of Onotoa Atoll. USGS f 1 1687, 51-L-8. Well-
worn specimens associated with Amphistegina and Cal car inn.

Caicarina- bean tin limesand from upper part of section above lagoon beach just south of Otoae village Maneaba, southern
main island of Onotoa Atoll. USGS f 11663, GOC-20A. Specimens mostly well preserved.

AmpAj'slejina-bearing limesand from lagoon floor in northern part of lagoon, about 4,600 ft S. 65° W. from lagoon end of
Government Station jetty, Onotoa Atoll. USGS f 1 1605, 51-S-ll. From bottom of reentrant or depression in large
lagoon reef patch.

Miscellaneous Foraminifera from limesand bottom at 14 ft in outer part of lagoon of Onotoa Atoll, slightly less than 4
miles N\ 85° W. from Aiaki Maneaba. USGS fl 1666, GOC-28. Among others, Heleroslegina suborbicalaris d’Orbigny
(a), Gaudryina ( Siphogaudryina ) rugulosa Cushman (b), Elphidium slrialopunclalum (Fichtel and Moll) (c), Placop -
sitina ? sp. (d), and Amphistegina madijascaricnsis d’Orbigny (e) are recognisable.

A mphislegina-boaring limesand from seaward edge of Aon te Halm reef, west side of north end of Onotoa Atoll, about
7,100 ft S. 50° W. from Tekawa church. USGS fl 1670, GOC-33. Worn Amphistegina with associated Heleroslegina
and Marginopora.

Worn Caicarina beach sand, stained dark from organic matter and corroded by organic acids. From top 6 in. in pit
GOC-6, north- central part of northern main island, about 2,400 ft north-northeast from Taneang-Tckawa Maneaba.
USGS f 11657, GOC-6A.

Co/cari'na-bearing sand interpreted as reef-flat horizon from bottom of 9- ft pit GOC-2, southern part of northern main
island, about 940 ft S. 25° E. from east (inshore) end of lagoon-side jetty at Government Station and 660 ft inshore
from sea beach along line bearing S. 87° W. at Pacific Science Board campsite. USGS f 11649, GOC-2F.

Caicarina sand, interpreted as transitional between beach and reef flat, from near bottom of 6-ft pit GOC-1, southern
part of northern main island, about 1,100 ft S. 41° E. from cast (inshore) end of lagoon-side jetty at Government
Station and 325 ft inshore from sea beach along line bearing S. 87° W. at Pacific Science Board campsite. USGS f 1 1642,
GOC-1 D. Both fresh (with spines) and worn specimens.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER »» PI.ATE 2 fi

FOHAMINIFBRA SANDS FROM ONOTOA ATOLL

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Occurrence and Significance
of Marine Animal Remains
in American Coal Balls

By SERGIUS H. MAMAY and ELLIS L. YOCHELSON

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-1

A description of intermixtures of marine animals
and land plants occurring in coal balls
in Illinois , Iowa , Kansas , and Oklahoma

UNITED STATES GOVERNMENT

PRINTING OFFICE, WASHINGTON : 1962

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UNITED STATES DEPARTMENT OF THE INTERIOR
STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Ciovcrnmcnt Printing Office
Washington 25, D.C. - Price SO cents (paper cover)

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CONTENTS

Past

Abstract 193

Introduction 193

Previous work 191

Acknowledgements. 194

Definition of coal balls 195

Occurrences of animal-containing coal balls - 190

McAlester, Okla — 190

Berry ville, 111. — - 197

Southeastern Kansas 199

West Mineral 199

Stratigraphic relations of the coal balls 200

Franklin 201

Monmouth — 201

Physical and biological features of coal balls 202

Normal coal balls ... 202

Homogeneous-mixed coal balls 203

Heterogeneous-mixed coal balls 204

Faunal coal balls 20Q

Paso

Chemical analyses 206

Laboratory nrethods .„ 207

Preservation of the fossils 210

Interpretation of nnimal-containing-coal balls 211

Heterogeneous-mixed coal balls 211

Homogeneous-mixed and faunal coal balls 213

Alternative interpretations ......... 215

Conclusions ..... 216

References cited 216

Details of the samples and insoluble residues 217

Oskaloosa, Iowa 217

McAlester, Okla 218

Southeastern Kansas 218

West Mineral .... 218

Monmouth ....... 219

Franklin 220

Berry ville, 111 220

Index 223

ILLUSTRATIONS

(Plates follow the Index!

Plate 26. Views at the Berryville, III., West Mineral, Kans., and Monmouth, Kans., coal ball localities.

27. Normal and mixed coal balls from Illinois and Kansas.

28. Faunal, mixed, and normal coni balls from West Mineral and Monmouth, Kuns.

29. Homogeneous-mixed coal balls from West Mineral, Kans.

30. Heterogeneous-mixed coal balls from Berryville, III.

31. Mixed coal halts from Illinois and Iowa, and limestone from Illinois.

32. Faunal coal balls from Monmouth, Kans.

33. Representative spores and other plant remains recovered from insoluble residues.

34. Representative animal remains recovered from insoluble residues. P«*e

Figure 42. Geographic occurrence of mixed coal balls. 197

43. Sketch of sawn surface of a normal coal ball 203

44. Sketch of sawn surface of a homogeneous-mixed coal ball — . 204

45. Sketch of sawn surface of a heterogeneous-mixed coal ball 205

TABLES

Pig*

Table I. Semiquantitativc spectroscopic analyses of coal ball and limestone samples 206

2. Rapid rock analyses of coal ball and limestone samples 207

3. Distribution of animal groups and large spores in insoluble residues .. 208

ill

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

OCCURRENCE AND SIGNIFICANCE OF MARINE
ANIMAL REMAINS IN AMERICAN COAL BALLS

By Seroics H. Mamay and Ellis L. Yochelson

AB8TRACT

Coal balls are mineralized nodular masses found within
some coal seums. Although coni balls have been known for
over 100 years, only botunical contents have been previously
reported in detail. In this pai>er, occurrences of marine animal
fossils associated with plant fossils in coal balls are described.

Three types of coal balls are here recognized: (a) normal
coal balls, containing ouly plants; (b) mixed coal balls, con-
taining both plants and marine animals; and (c) faunal coal
balls, containing only animals. Mixed coal balls are homo-
geneous, if the plant and animal remains are mixed throughout
the matrix, or heterogeneous, if the marine fraction is clearly
segregated from the normal fraction.

Homogeneous-mixed coal balls were found neur McAlester,
Okla., near Oskaloosa, Iowa, and in parts of the southeastern
Kansas coal fields. Heterogeneous-mixed coal balls were found
near Berryvllle, III., and faunal coal bulls were found at two
localities In Kansas.

Coal balls are particularly common near West Mineral,
Kans. They are abundant in the Fleming coal, of lies Moines
age. and also occur in the underlying Mineral coal. Observa-
tions of mining waste suggest that mixed coal balls constitute
1 to 2 percent of the coal balls recovered, although none were
found in place. There may be some positive correlation be-
tween abundance of coal balls and elevations or “highs" in the
Fleming coal.

Hemiquantitative spectroscopic analyses and rapid chemical
analyses of selected coal balls are included In this report.
These contain the most comprehensive data on the chemical
composition of coal balls yet published.

Other samples were dissolved in formic add ; the residues are
described. Uncompressed spores were recovered from many
of the samples, along with diverse animal remains. Selected
s]>ecimens of spores and animals are figured, and identifiable
forms are tabulated.

The fossils are replaced by a variety of minerals, occasion-
ally within the same coal ball. S)>ore fillings from a single
coal ball may be pyritlc or ealenreous. Gastropods may be
calcareous, pyrltie, or baritic in the same sample. Felecypods
recovered are pyritlc or baritic. Some echiuoderm columnals,
cepbalopods, and brachiopods are pyrltlzed, and others are
calcareous.

The presence of marine animals within coal balls Is evidence
of transportation of material from a marine environment to a
uonmariue environment. Though all coal balls have hereto-

fore been considered concretionary in origin, mixed and faunal
coal balls are, at least in part, of clastic origin. The swirled
texture of some homogeneous-mixed coal balls Is further evi-
dence of transport.

It is suggested that heterogeneous-mixed coal balls were
formed when mud rollers containing animal remains were
brought Into the coal swamp by temporary marine Inundation
and were secondarily surrounded by normal coal ball material.
Some homogeneous-mixed coal balls may represent discrete
lumps of transported fosslllferous mud. The animal content
of still others may have been introduced into the coal swamp
in a mud slurry. These temporary marine Inundations may
have provided a source of calcium carbouute for the formation
of some normal coal balls.

INTRODUCTION

In a previous publication (Mamay and Yochelson,
1953) we briefly reported the occurrence of marine
fossils associated with land plants in coal balls of
Pennsylvanian age. Subsequent field observations and
accummulation of additional material have made
possible a more detailed report.

Although the occurrence of coal balls has been known
for more than a century and although they have been
noted in the coal fields of various European countries
and of the United States and Great Britain, we are
not aware of any authenticated reports, earlier than
1953, of faunal inclusions within coal balls.

Darrah (1939, p. 135) stated that, “many of the
Belgian and English coal balls contain fossil cephalo-
pods,” but he presented no further information. Coal
ball deposits in England and Belgium are overlain by
marine beds containing abundant fossiliferous nodules,
in which goniatites are the predominating fossil;
St opes and Watson (1908) and Leclercq (1952) dis-
cussed in detail this relation of British and of Bel-
gian coal ball deposits, respectively. Since extensive
research has been done on both British and Belgian
coal balls but no mention has been made of animals
within the nodules, there is a possibility that Darrah

193

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194

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

neglected to distinguish between roof-shale nodules and
true coal balls.

Douville (1905), who discussed brief!}' the content
of a few nodules from the coal fields of Yorkshire,
England, recognized two types of coal balls, one con-
taining only plant debris, the other containing sparse
woody fragments among numerous marine shells. The
second type were illustrated (Douville, 1905, pi. 6)
as “Coal Halls du Yorkshire,” but it is apparent that
these specimens are actually roof nodules, distinct from
the coal seam itsel f.

It may be that animal remains simply do not occur
in coal balls of Europe or England. Alternative rea-
sons may be the facts that the primary interests of most
previous investigators were botanical and that most
British studies were based on specimens obtained from
professional collectors and were not seen in the field
by the paleobotanists. The material on which the
present report is based is unusual in that it contains
not only the plant remains ordinarily associated with
coal balls, but diverse assemblages of marine animal
fossils ns well. Because of its significance for the
origin of coal balls, this material is described in detail.

PREVIOUS WORK

Although earlier workers, particularly W. C. Wil-
liamson, wrote many papers on the plant content of coal
balls, it was not until 1908 that the geological aspects
of coal balls were extensively discussed in the classical
publication bv Stopes and Watson (1908). Their
paper reviewed all the pertinent informat ion available
at the time, and included several chemical analyses of
coal balls. Stopes and Watson concluded that coal
balls were formed in place, as a product of percolating
marine waters.

Since the time of Stopes’ and Watson's publication
little has been written on the occurrence and formation
of coal balls, However, many publications have dealt
with the anatomy and morphology of plants preserved
within coal balls, and a number of significant botanical
facts have been reported. The years 1935-60 have seen
a rapid expansion of this field of paleobotany in the
United States, but a considerable waning of interest in
England and Europe, where most of the early work
was done.

Studies of coal balls in the United States were sum-
marized in detail through 1950 by Andrews (1951).
This summary includes a sketch of the history of coal
ball research in Europe, as well as a brief discussion of
the chemical composition and geological occurrences of
coal balls.

'l'he study reported here was started in 1952, when
Mamay made a large collection of coal balls in south-

eastern Kansas and southern Illinois. Previously,
Mamay s interests were centered on morphological as-
pects of the plant content of the coal balls, but his at-
tention was drawn toward the geologic problems raised
by the animal fossils found in a few of the coal balls.
The presence of abundant gnstrojxxls among these
faunas resulted in Yochelson’s participation in the
study, because of his interests in that group of animals.
A preliminary account of this discovery was published
(Mamay and Yochelson, 1953) because of the great
rarity of known occurrences of marine animal remains
within Paleozoic coal seams.

In May 1955, we studied field relations and collected
more coal balls from previously known and from new
localities. Interested paleobotanists contributed addi-
tional coal balls. Excellent examples of animal-con-
taining coal balls were also found in previously un-
studied coal balls collected near McAlester, Okla., by
Charles B. Read. Laboratory studies were carried out
during 1955 and 1956, and Mamay revisited some of
the localities in 1957.

Two other short publications resulted from this study.
Associated with the McAlester, Okla., coal balls were
a number of calcareous fossiliferous nodules that pre-
sumably originated from the overburden of the Secor
coal. The nodules contain a number of species of Fo-
raminifera, some of which were epiphytic on a prob-
lematical alga, Litostroma. The Foraminifera were
described and their deposit ional environment was dis-
cussed by Henbest (1958); Mamay (1959) described
Litostroma in detail.

ACKNOWLEDGMENTS

Our colleagues Charles B. Read and James M. Schopf
provided locality information and on several occasions
helped us by their discussions of the coal balls. Emil
Sandeen and Kenneth Moore of the Pittsburg and
Midway Coal Co. and II. W. Compton of the Aj>ex-
Compton Coal Co. not only allowed access to their
mining properties but provided valuable information
regarding the occurrence of coal balls. Robert \V.
Baxter, University of Kansas, and Ilenry X. Andrews,
Washington University, St. Ixiuis, Mo., allowed us to
examine their collections of coal balls and gave select
specimens for study. Baxter also supplied geologic
information and additional specimens from Monmouth,
Kans., having visited that locality at our request in July-
1957. We appreciate also the cooi>eration by other
U.S. Geological Survey colleagues: Mona Frank and
P. L. I). Elmore made the spectroscopic examinations
and Paul W. Scott made the chemical analyses.
Charles Milton identified several minerals, and S. O.
Schlanger aided in interpretation of sedimentary

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195

phenomena. Systematic identifications are to be
credited as follows: Protozoa, Lloyd G. Henbest;
Coelenterata and Bryozoa, Helen Duncan; Cephalo-
poda, Mackenzie Gordon, Jr.; Ostracoda, I. G. Sohn;
Trilobita, A. R. Palmer: and conodonts, the late Wil-
bert II. Ilass. David II. Dunkle of the U.S. National
Museum examined the fish remains, and David Nicol,
formerly of the U.S. National Museum, checked identi-
fication of the j>elecyiK)ds. Robert M. Finks, Brooklyn
College, identified sponge material, and R. M. Kosanke,
Illinois State Geological Survey, checked spore
identifications.

DEFINITION OF COAL BALLS

The results of this study show that coal balls are
considerably more varied, texturally and biologically,
than is ordinarily supposed. It is thus evident that
some expansion of longstanding concepts is necessary,
as well as some refinement and revision of definitions.
Our emended definitions are presented here, before
descriptions in detail of the various kinds of coal balls.

In classical usage (Stopes and Watson, 1908, p. 168)
the term “coal balls” has been applied to nodular
mineralized masses of petrified plant material that
occur within coal seams. The balls are largely re-
stricted to coals of Pennsylvanian or equivalent age. 1
and generally have been considered to be concretionary
in origin. There are no known occurrences in anthra-
citic coals.

Coal balls are of various physical and chemical fea-
tures. They may be calcareous, pyritic, dolomitic,
sideritic, or even siliceous in composition. Within
limits, coal balls with high proportions of calcium car-
bonate have the best preservation of cellular detail;
ns a general rule, high pyrite content results in poor
preservation of the plant fossils. The balls may occur
as small individuals no larger than a plum, or they
may weigh as much as several hundred pounds and
may form huge intergrown masses that displace the
coal for areas of several square yards. The individual
nodules may bo spheroidal, approximately lenticular,
or irregular in shape. At a few localities, particularly
in England and Europe, spheroidal specimens are
very abundant, but at others, flattened, roughly lentic-
ular coal bulls seem to predominate. Coal balls may
occur anywhere between the upper and lower limits of
a coal seam, but they are more common in the upper
half. In many places they cause humps in the upper
surface of the coal, where they are separated from the
overlying rocks by only a thin veneer of coal. Their

1 Gotlmn (1011) n*jw>rt«Ml inns*t** of iwtrlllcd plant material In Onr
man TVrflnry brown cnali*. which he considered to be antilogous to coni
ball*. The plant- arc preserved lit slderllt*. however, and are not as
well preserved aw those In Carboniferous coal bulls*. Little more is
known of this Tertiary occurrence

562601 0—62 2

occurrence in a given coal seam may be either extremely
sporadic or regular; many seams contain none at nil.

Despite these varying factors, two primary features
have been necessary for identification of a sedimentary
rock as a coal ball, as heretofore understood : (a) that
it contain histologically investigable fossil plant ma-
terial, impregnated with and surrounded by a mineral
matrix of nonvegetable origin, and (b) that it be
indigenous to a coal seam.

Schopf (Whitehead and others, 1952, p. 290) reported
an occurrence of coal ball limestone in a marine coquina
above a coal seam. According to Schopf, this obviously
formed within the precoal peat bed and was reworked
into its present position ; it thus is not in conflict with
this definition.

This study shows that coal balls may vary as much
in their enclosed organic remains as they do in any
other mensurable feature. Thus a realistic definition
of coal balls should he expanded so that “inclusion of
histologically investigable plant material” is replaced
by “inclusion of fossil animal material, histologically
investigable fossil plant material, or both, in varying
proportions” ns one of the two primary requisites for
identification of a rock as a coal ball, its inclusion
within the limits of a coal seam remaining the other.
The definition is further emended to include in its scope
objects of either clastic or concretionary origin, their
inclusion within the coal seam rather than source of
component fossils being the important factor.

Carrying this concept to an extreme, it might be
argued that any fossiliferous lens in coal is a coal ball,
but this is fallacious logic. Coal balls are relatively
small, discrete masses of nodular aspect, usually but
not always wholly concretionary. They generally
show a vertical distribution throughout the coal, rather
than a lateral continuity such as characterizes a split,
parting, or lens within a coal. The essential feature
of the primarily clastic coal balls is the exotic nature
of some of their fossil content, which is foreign to the
immediate environment of coal dej>osition. In no
sense are the clastic coal balls a normal part of the
sedimentary cyclothcm characteristic of Pennsylvanian
sedimentation. We believe that their presence within
a coal seam along with the more usual, concretionary
type of plant-containing coal balls is attributable to
unusual, probably catastrophic and transitory means
of landward redeposit ion, such as might be effected by
violent storm wave or tidal wave action.

It is emphasized that this broadened definition of
coal balls is made only on the basis of specimens that
can lx* shown, by virture of coal remnants on all or
nearly all unfractured surfaces, to have originated
within a coal scam. The various types of fossiliferous
nodules that occur in the shaly or limy overburdens of

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

some coal seams are not regarded as coal balls because
of their formation outside the coal seam. (See Stopes
and Watson, 1008, p. 204-210, for discussion of goni-
atite-bearing nodules that occur in roof shales of some
seams and occasionally contain well-preserved plant
remains.)

The objects defined here as coal balls fall into three
primary types, on the basis of biological content, and
two subsidiary types, on the basis of textural features.
The term “coal balls,” unqualified, is used here for all
these types. Although there is some intergradation in
the relative proportions of plants to animals, for the
sake of convenience coal balls may be classified as
follows:

1. Normal coal balls: contain only plant fossils (pi. 27,

fig. 1; pi. 28, fig. 2).

2. Mixed coal balls: contain both plant and animal

fossils.

(a) Homogeneous type : shows no distinguishable

segregation of plant and nnimal fossils
(pi. 27, figs. 2— i; pi. 28, fig. 3; pi. 29, figs.
1-3).

(b) Heterogeneous type : shows distinct segrega-

tion of plant and animal fossils (pi. 30,
figs. 1-3; pi. 31, fig. 1).

3. Faunal coal balls : contain exclusively zoological fos-

sils (pi. 28, fig. 1; pi. 32, figs. 1-8).

Type 3 is very rare, and insofar as we know, has been
found in significant quantities at only one locality.
Type 2(a) (homogeneous-mixed) is by far the common-
est type of animal-containing coal balls, while type
2(b) (heterogeneous-mixed) is, again, known to us
from only one locality.

The following evidence supports this expanded con-
cept of coal balls: In one coal ball (sample E-13, from
Patik Mine, Iowa, pi. 31, fig. 4) animal remains are so
rare as to be hardly noticeable on sawn surfaces, but
acid solution produced a large number of small animal
fossils, some of them unquestionably of marine origin.
However, the plant debris is extremely well-preserved,
and it is probable that casual inspection would lead to
identification of the specimen ns a normal coal ball.

It is possible to demonstrate a gradational series in
which the proportion of animals to plants increases
from the above-mentioned extreme in which nnimal
remains are rare but present, to the point where plant
remains are rare or even absent, ns in some of the faunal
coal balls. The faunal coal balls appear in the same
seam with poorly preserved normal coal balls. There
is no sharp line of demarcation between them and more
intermediate specimens with higher proportions of
plant fragments.

Comparison of normal coal balls from the Berryville,
111., locality with the normal coal ball matrix surround-

ing the marine fraction of heterogeneous-mixed coal
balls from the same locality indicates that the two are
identical in physical composit ion, in texture, and in
botanical content, as shown by study of peels and insol-
uble residues.

OCCURRENCES OF ANIMAL-CONTAINING COAL BALLS

Mixed coul balls were collected from localities in
four States in the eastern interior and midcontinent
coal basins: Illinois, Kansas, Oklahoma and Iowa. The
Oklahoma deposit is no longer accessible. The Illinois
specimens were found at a spot locality. The Kansas
material, however, originates from an economically
important mining area in the southeastern purt of that
State. This area has produced abundant coal balls
from three different coal seams and has been the geo-
graphic source of much of the geologic information on
the occurrence of mixed coal balls. The Iowa material
consists of one coal ball from the Patik mine near
Oskaloosa, presented to us by R. W. Baxter, University
of Kansas.

Schopf (1941) published a chart showing important
coal-ball stratigraphic levels in the United States and
their correlation with European occurrences. Since
this chart was prepared, only slight modifications in
the correlations have been made (Moore and others,
1944: Wanless, 19. r >6), so the chart is not repeated here.
Geographic distribution of the mixed coal balls is
shown in figure 42.

McALESTER, OKL A .

A small collection of coal balls from the Secor coal
near McAlester, Okla., was made by C. B. Read in
1939. Only a few of the specimens were sectioned be-
fore 1993, and all those were of the normal type. Sec-
tioning of the remainder showed that some were of the
mixed type.

The collection was made at a small abandoned slope
mine on the property of Mr. Joseph Lemont near the
abandoned railroad station of Chambers, about 4 miles
south-southeast, of McAlester. The mine site is ap-
proximately at the common comers of secs. 26, 27,
34, and 39, T. 5 N., R. 14 E., Pittsburg County. This
locality (USGS paleobotanical loc. 8764) was re-
visited by us in 1955, but only a few badly weathered
loose coal balls were found. These all were of the
normal type and no information was available regard-
ing their original placement in the coal seam. The
slag heap contained fragments of an impure bioclastic
limestone. Similar limestone that was collected by
Read cor robo rates a statement by Mr. Lemont that at
the mining site the coal seam was overlain by a thin
fossiliferous limestone.

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

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Ficcre •12. (ipoirruplilc occurrence* of mixed coal twill* In the United States: 1. McAlester, Okla. : 2. southeastern Kansas: 8. Oskaloosa,

Iowa : 4. Berryville, 111.

Waste heaps of two other small abandoned mines
in the nearby vicinity of the Leinont property (SW*4
SW%SW% sec. and N E J /i X E V) N E Vi sec. 34) were
also searched for coal balls but none were found; only
a few large scaphopods and poorly preserved peleypods
were found.

Along the highway between Hartshorn anti McAles-
ter, we examined several large abandoned strip pits
in the McAlester coal in the McAlester shale, 1,200-
2,500 feet below the base of the Boggy formation. A
large abandoned strip pit where the Secor coal had been
mined in the southern half of sec. 33, T. 5 X., It. 15 E.,
was also searched. None of t hese pits yielded coal balls.

The Secor coal is the oldest seam known bv us to
have produced mixed coal balls. According to Hen-
dricks (1937), the Secor coal seam varies from 1 to 3
feet in thickness. It lies about 350 feet above the base
of the Boggy formation in the Krebs group, of Des
Moines age (Miser, 1951). Hendricks mentioned no
fossiliferous limestone above the Secor coal: perhaps
he did not observe it either because of its localized
occurrence or because it is covered over large parts of
the area.

BERRYVILLE, ILL.

The locality known in the literature as Berryville,
1 11., was discovered by J. Marvin Weller in August 1939
(Schopf, 1956, written communication). It is on the
farm of Ralph Brian, 6 miles south and 2 miles west of
Sumner, 111. (approximately SW 14 NEV 4 NW 14 sec. 7,
T. 2 X., R. 13 W., Lawrence County; USGS paleobo-
tanical loc. 9190). Since its discovery, this deposit has
become well known to students of coal ball lloras of the
United States and has provided them with an unusual
quantity of excellently preserved plant fossils, many of
which have been described. The deposit is of further
interest as a source of heterogeneous-mixed coal balls.

The coal balls occur in a thin seam of coal, considered
by Schopf (1941) and others to be the Calhoun coal, in
the upper part of the McLeansboro group of Middle
and Late Pennsylvanian age. The outcrop is limited,
being exposed for a distance of less than 60 feet along
the south bank and bed of a small intermittent stream.
The streambank cuts into the side of a steep hill, and a
thick alluvial overburden hampers efforts to excavate
the coal balls. Intermittent flooding of the stream

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

erodes coal halls from the outcrop, so that collections
may be made from float in the nearly dry stream bed.

Several dozen fresh coal balls were collected at Berry -
ville. Many of these were taken from the outcrop and
broken in the field but none proved to be of the mixed
type. A few heterogeneous-mixed specimens were
found in float along the stream bed, but these give no
indication of their original position within the coal
seam. The locality was revisited in 1957 by Mamay,
who excavated heterogeneous-mixed coal balls in place
and found that they extend throughout the thickness of
the coal seam.

The outcrop area is shown on plate 26, figure 3. Be-
cause this exposure represents one of the few localities
known to us where coal balls may be observed in place,
the hillside adjacent to the outcrop was trenched and a
section measured. The trench is seen along the right
side of the photograph. The section consists of the fol-
lowing lithologic units:

A/eaeured section at Bcrryville, III.

Alluvium. FVet

Sandstone, light-gray, flue-grained ; weathers dark gray ;
bedded in %-ln. laminae near base; becomes more

massive upward 1.5

Shale, dark-brown, micaceous, with abundant fragmen-
tary plant compressions ; locally subflssile; poorly ex-
posed 8. 1

Limestone, dark-gray ; highly crtnoldal In a single massive
bed ; weathers very dark gray below and yellow Iron

stained above 1 . o

Coal, moderntely hard, banded, with blocky fracture:
coal balls rare in lower 3 In., but become more numerous
upward : some cause bulges in the upper surface of the

seam. Average thickness of unit 2.0

Underclay, light-gray, slickensided with blocky structure:
slightly arenaceous with scattered plant compressions;
upper surface slightly Irregular. Base not exposed, but
thickness of unit at least 2. 0

Total thickness measured 12. 0

Examination of the coal seam face revealed the fol-
lowing distribution of the coal balls:

1. Tiie relative abundance of the coal balls varies con-

siderably within short horizontal distances; one
spot may contain many, another a few feet away
may have none.

2. Coal balls occur throughout the thickness of the seam.

3. Coal balls may occur at the base of the seam with

only a thin film of coal below, and may even indent
the subjacent underclay. Commonly, however,
they seem to increase in abundance toward the top
of the seam.

4. Tho coal balls that occur at the top of the seam may

produce a bulge .that protrudes into the overlying
limestone. In all places observed, however, they

were separated from the limestone by at least a
thin film of coal.

5. The coal balls may be discrete lumps separated from
each other by several inches or more of coal, or
they may occur in large irregular intergrown
masses that largely displace the coal seam for
several square feet and contain only thin, irregu-
larly oriented coal partings. One such mass is
shown in plate 20, figure 2. This block of coal
ball material, weighing perhaps a ton, stands iso-
lated in the streamlxid. It consists of many closely
associated, irregularly shaped but discrete masses
of coal ball material separated from each other by
thin streaks of coal. Although tho overburden is
completely eroded away, the intact condition of
the underlying coal suggests that this mass is
in its original position. It consists almost ex-
clusively of the roots and other debris of the marat-
tiaceous fern genus Pmrottiun, a dominant form
in the Berryville flora.

Although nothing unusual was noted in the measured
section, a somewhat involved sequence occurs a few
yards downstream from the trench exposure (to the
left of the, trench in pi. 26, fig. 3) . There the limestone
overburden of the coal seam thickens abruptly to form
a conspicuous mass approximately 5 feet, thick. The
coal beneath this limestone mass is reduced to approx-
imately half its maximum thickness (see pi. 26, fig. 1),
presumably by channeling, and the depression is filled
with a mixture of detrital coal and limestone chunks,
which grade into solid limestone above. A sample of
the limestone blocks within the channel filling, when
dissolved in acid, proved to contain almost the same
type of plant and animal remains as the mixed coal
balls. The coal immediately below the channel filling
contains abundant limestone blocks; a representative
sample included:

1. A typical, well-preserved normal coal ball containing

a large undistorted fragment of the fructification
of Botryopteris.

2. Several chunks, approximately 1 inch thick, com-

posed of numerous particles of coal ball-like ma-
terial in a coal groundmass and interbedded locally
with stringers of coal. The brown coal ball par-
ticles arc subangular to subrounded; they are
closely packed and some are even molded into one
another. The latter characteristic indicates that
tho particles were plastic when the rock was
formed. The particles contain mostly well-
preserved, uncompressed spores (see analysis of
residue of sample E-15) and bits of cuticle, but
no animal remains. They may represent an ag-
glomeration of detrital coal ball material that was

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

199

finely divided at the time of channeling of the coal
seam. Illustrations are given on plate 31.

3. Two pieces of gray crinoidal limestone, surrounded
by coal and locally intermixed with or separated
from the surrounding coal by brown petrified plant
debris.

SOUTHEASTERN KANSAS

The southeastern Kansas coal field contains some
of the richest known occurrences of coal balls in the
United States (Andrews and Mamay, 1952), and con-
sequently has been the geographic source of much of
the information presented here. Several coal ball lo-
calities were visited by us hi Cherokee and Crawford
Counties; most of these were found by a systematic
investigation of the strip-mining operations mapped
by Abernathy (1946, pi. 1). A more up-to-date map
of stripping operations in the area, published privately
in 1952 by the Apex-Compton Coal Co., Inc., was also
helpful in this search.

WEST MINERAL KAN'S.

Investigations of this area were concentrated at the
site of stripping operations of the Pittsburg and Mid-
way Coal Co., at their Mine No. 19, in sec. 5, T.
33 S., It. 22 E., Cherokee County. This site was selected
because of the extensive scope of mining operations,
the abundance of coal balls, and the relative freshness
of the material.

In spite of the many coal balls found at the Pitts-
burgh and Midway mine, observations of their field
relations were restricted by the sporadic occurrences
of the coal balls and by the nature of the mining
methods. Large-scale stripping operations are used
because of the thickness of the overburden (as much
as 50 feet); consequently, the relations of the coal to
the overburden are usually concealed by slump from
the steep walls of the pits.

The overburden is removed in long swaths of several
thousands of square yards by either a dragline or an
electric shovel. The upper surface of the coal is thor-
oughly cleaned. Once exposed, the coal is broken by
a pinning machine, loaded, and taken to the tipple for
washing and sizing. 2

The mining procedure, while highly efficient, does
not result in a clenn working face, so thut position of
the coal balls within the coal is usually badly disturbed.
The procedure also limits observations of the relation
of the coal to the underlying sedimentary rocks, for
little of the latter are removed. Furthermore, loading
usually takes place shortly after breaking of the coal,

•Mine operations at the Pittsburg and Midway Mine are more com-
pletely described Sn Coal Age (1954).

so that one would have to be present at about the time
the coal balls are uncovered to observe them in place.

In addition to the limitations imposed by the mining
methods, three other factors restricted our observations.
First, at the time of our visit, even though a large area
of coal was exposed, few coal balls were being un-
covered. Second, in 1905, mining was limited to a
single pit, and it was not possible to make comparative
observations at fresh exposures over a broader area.
Third, as usual in large strip-mining operations, aban-
doned pits that might have contained good exposures of
the coal and overlying strata in their walls were either
refilled with overburden or flooded to levels above the
coal.

Our observations, however, have been supplemented
by those of the miners and pit operators. Particularly
valuable information was derived from discussions with
Emil Sandeen, mine superintendent of the Pittsburg
and Midway Coal Co., and with Kenneth Moore, mining
engineer. Mine No. 19, and from mining records of that
company, to which we were given access.

The mining method necessarily results in contamina-
tion of the coal by coal ball material and minor amounts
of underclay. Where the balls occur abundantly, they
are a major nuisance since they are imbedded in the
coal and must be loaded and transported to the washing
plant for removal. The waste removed from the coal
in the washing process varies from day to day, partly
because of the sporadic occurrence of coal balls, and
sometimes may constitute more than 30 percent of the
gross tonnage mined. Coal balls form a large part of
this impurity.

Despite the inconvenience of commercially worthless
coal balls, their occurrence is not a total loss to the mine
operators. The coal balls, being of much higher spe-
cific gravity than the coal, are easily removed in the
washing plant. The coal balls are hauled from the
tipple and piled in a nearby vacant area until they are
needed for road construction. Their hardness and
durability make them an excellent ballast for access
mine roads, a fact that has been fully exploited at the
Pittsburg and Midway mines, where this supply of bal-
last is seemingly endless ! Part of one such pile, which
was perhaps 6 feet high over an area of half an acre,
is shown in plate 26, figure 4 — a heap of possibly several
thousand tons of almost pure, structurally preserved
fossil material. Another indication of the abundance
of coal balls at the Pittsburg and Midway mines was
observed in a newly constructed roadbed, some 1,800
feet long, 50 feet, wide, and 2 to 3 feet deep. It was
estimated that between one-quarter and one-half of the
volume consists of coal balls.

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

STRATIGRAPHIC RELATIONS OF THE COAL BALLS

Two closely associated coal seams are mined by the
Pittsburg and Midway Coal Co. These are the Flem-
ing and the Mineral seams, both of which occur near the
bottom of the upper one-third of the Cherokee shale
of I)es Moines age. The Fleming is the uppermost
coal. It ranges from 12 to 18 inches in thickness and
lies from 8 to 20 feet above the Mineral coal, the thick-
ness of which ranges from 18 to 21 inches. Both seams
locally contain coal balls, but. the balls are far more
abundant and widespread geographically in the
Fleming coal.

The Mineral coal, although of more sporadic occur-
rence than the Fleming, apparently more consistently
maintains a single stratigraphic level. It may be pres-
ent directly beneath the Fleming coal, or present in an
area where the Fleming coal is absent. On the other
hand, the Mineral coal may be absent from an area that
does contain the Fleming coal.

In contrast to the flat-lying Mineral coal, the Flem-
ing coal undulates, varying in vertical distance from the
underlying seam. It may be flat and almost parallel
to the Mineral coal for a large area, but locally it rises
to form structural “highs” that extend as much as 12
feet above its general level. The “highs” may form
domes as much as 100 feet across or ridges extending
along the seam for 500 to 1,500 feet (K. E. Moore, 1957,
oral communication). They are usually accompanied
by a thinning of the coal at their crests. In areas
where the Mineral coal is generally absent, an isolated
patch of it may be present directly below a “high” in
the Fleming coal.

The overburden of the Mineral seam also differs
from that of the Fleming seam. The Fleming coal
is overlain by a dark-gray to black fine-grained marine
shale, rich in productoid brachiopods (Williams, 1938,
p. 105). According to Mr. Moore, a limestone is not
known to overlie this seam at the Mine No. 19 area.
On the other hand, over broad areas, the Mineral coal
is overlain by a hard massive impure fossiliferous lime-
stone as much as 20 inches thick, which may change
laterally in a short distance to a black shale similar to
that above the Fleming coal. At one exposure at Mine
No. 19, we observed a limestone 20 inches thick directly
above the Mineral coal; 50 feet away, the coal was
overlain by the fossiliferous shale. No coal balls were
observed in the coal beneath the limestone.

The coal balls show the following relations to the
two coal seams:

1. Relative abundance of coal balls, in general, shows
considerable local variation. At Mine No. 19, the
dragline pit (sec. 6, T. 33 S., R. 22 E.) had pro-
duced few coal balls, while the shovel pit, less

than two miles away (SWt/j sec. 32, T. 32 S., R.
22 E.), had produced many.

2. Of the two seams, the Fleming coal produces by

far the most coal balls.

3. A previous statement, by us (1953) that coal balls

occur only beneath a marine limestone caprock is
erroneous, as is strikingly illustrated by the abun-
dance of coal balls in the Fleming coal, where a
marine limestone cap is absent. Furthermore,
there seems to be no correlation between limestone
and coal balls in the Mineral coal, where both are
known to occur. Thus it appears that the one con-
dition found consistently in occurrences of coal
balls is that the productive seam is directly over-
lain by a marine bed, regardless of its lithology.
Feliciano (1924, p. 233) cast some doubt on this
but did not present detailed evidence.

4. The coal balls are generally more abundant in the

upper half of the seam, but are known to occur
throughout the thickness of the coal. In some
places they replace almost the entire coal seam
over areas of many square yards.

5. In the Fleming coal the abundance of coal balls seems

to be related to the elevation of the coal seam. It
was brought to our attention by Messrs. Sandeen
and Moore, as well as by several of the Pittsburg
and Midway Coal Co.’s shovel operators, that coal
balls in the Fleming seam are usually concentrated
at the “highs.” Mr. Moore stated that, tipple
waste from “high” areas of the Fleming coal usual-
ly is greater than that from “low” areas in the
seam, and may reach as much as 37 percent of the
total volume, a large part of this waste consisting
of coal balls. Sporadic occurrence of coal balls
within a given coal seam has been reported pre-
viously (Cady, 1936, p. 158; Andrews, 1951, p. 433)
and probably is characteristic of all deposits con-
taining coal balls. Whether these other sporadic
occurrences are also associated with “highs” in the
coal remains to be determined.

These facts may have some bearing on the overall
problem of coal ball formation, but they shed no light
on the outcrop relations of mixed coal balls to normal
ones. However, it is known that the two types do
occur very close to each other. Along one of the mine
access roads at the West Mineral, Kans., locnlity, there
had been dumped, intact, a nest of coal balls approxi-
mately 3 feet square and 1 foot thick. The lower
surface of the nest bore a 2- to 3-inch layer of coal ; its
upper surface bore a thin film of coal, super post'd by an
inch or so of black fossiliferous shale whose surface
undulations marked the positions of the individual coal
balls. Several of these were broken from the upper

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

201

surface of the nest, and two proved to contain animal
remains as well as moderately well preserved plant
fragments; the rest of the collection consisted of normal
coal balls with well-preserved plant structures. Thus
it is at least known that mixed and normal coal halls
may occur within 2 or 3 feet, horizontally, and a few
inches, vertically, of each other.

Most of the mixed Kansas coal balls were collected
from the roadbeds and ballast heaps of the Pittsburg
and Midway Coal Co. Although it was not possible to
observe the relation of mixed coal balls to normal coal
balls or to arrive at any understanding of their real
distribution, it was possible to gain some idea at least
of their relative abundance. Mixed coal balls are no
rarity at this particular locality, but, on the basis of
examination of perhaps 4 or 5 miles of roadbed expo-
sures and of the several large waste heaps in the area,
we estimate that mixed coal balls constitute no more
than 1 to *2 percent of all the coal balls spread about
the Pittsburgh and Midway Coal Co.’s grounds.

The mixed coal balls show about the same range in
size and shape as those of the normal specimens; several
were more than 2 feet in greatest dimension and several
hundred pounds in weight. Mixed coal balls were not
concentrated at any one place, but were fairly evenly
distributed among the normal coal balls and were found
among the waste heaps and roadbeds of the abandoned
Mine Xo. 15 as well as those of the then active Mine
Xo. 19. This suggests an areal distribution approxi-
mating that of normal coal balls in the Fleming coal.

FRANKLIN, KARS.

Large heaps of coal balls were examined at the
dumps of the Mackie-Clemens Mine Xo. 22 (SE 14
sec. 24, T. 28 S., R. 25 E., Crawford Comity) and
Mine Xo. 23 (XW% sec. 21, T. 29 S., R. 25 E., Craw-
ford County), east of Franklin, Kans. A few mixed
specimens were found at the latter locality, an airline
distance of nearly 30 miles from the Pittsburg and
Midway Coal Co. pits.

Abernathy (1946) indicated the coal mined there
to be the Mineral coal, but local inquiry indicated
that the seam is considered by some miners to be the
Fleming coal. On the basis of plant content and physi-
cal appearance, the coal balls examined there seem to be
identical with those at West Mineral, where the Flem-
ing coal yields most of the coal balls. Several other
pits and dumps in this general area were examined
without finding coal balls.

MONMOUTH. KANS.

The Bevier coal is exposed in an open-pit- mine of
the Apex-Compton Coal Co., in XW% sec. 12, T. 31
S., R. 22 E., Crawford County, near Monmouth, Kans.

0—83 8

According to Abernathy (1946, p. 139) the Bevier
coal lies above the Fleming and Mineral coals, about
ltX) feet below the top of the Cherokee shale. The
roadbeds at the Monmouth pit, like those at the Pitts-
burg and Midway Coal Company, are composed
largely of coal ball material, indicating regular and
abundant occurrences of coal balls. But curiously
enough, the coal balls themselves are predominately
pyritizcd faunal coal bulls or specimens containing neg-
ligible plant material. Only a few specimens of plant-
bearing coal balls were found, and these are composed
almost exclusively of fusinized wood fragments in-
stead of the heterogeneous, calcified, and more or less
well-preserved plant debris that occurs in normal coal
balls. Thus it appeal's that the ratio of normal to
animal-containing specimens at other deposits is almost
reversed at the Apex-Compton mine, for the normal
coal balls there constitute the smaller percentage, per-
haps even a smaller percentage of the total than do
the mixed coal balls at the Pittsburg and Midway
pits.

The active pit was flooded at the time of our 1955
visit, and it was not possible to sec the coal balls in
place, but the following information regarding this
curious occurrence was provided by H. W. Compton,
owner of the mine :

1. A limestone has not lieen noted immediately above

the coal in the Apex-Compton pits. The immediate
overburden of the coal seam is a dark-gray slightly
fissile shale containing product id brachipods, pec-
tenoid pelecypods, and poorly preserved plant im-
pressions near its contact with the coal. This shale
ranges from 3 to 6 feet in thickness and is overlain
by a 3- to 6-inch layer of medium dark-gray
argilaceous unfossil iferous limestone; above the
limestone is a light-gray nonfissile unfossiliferous
shale. The overburden apparently lacks concre-
tions and is generally very poor in fossils.

2. Coal balls are abundant and occur throughout the

thickness of the seam. In some places they are so
highly concentrated as to form sizable humps in the
surface of the coal. As an exceptional example of
the high proportion of the coal seam sometimes
represented by coal ball material, Mr. Compton
cited one particular pit, 80 feet wide and approxi-
mately one-half mile long, in which the coal was
so heavily cont aminated with coal halls that the pit
was abandoned.

3. Although the surface of the coal seam shows some

undulation, no correlation has been observed be-
tween the "highs” and coal ball occurrences, except
where t he elevations are actually caused by unusual
concentrat ions of coal balls.

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202

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

In July 1057, Robert W. Baxter, University of Kan-
sas, visited the Apex-Compton mine at our request,
in order to study the field relation of the faunal coal
balls under better conditions than those we found in
1955. Baxter's observations substantiate the above
descriptions. He succeeded in observing, photograph-
ing, and collecting faunal coal balls in place at. the
working face of the coal seam, and forwarded us
specimens and photographs for inclusion in this report.
Part of the coal seam with two faunal coal balls in
place is shown in plate 26, figure 5; sawn surfaces
of these two specimens are shown in plate 32.

Baxter wrote us :

The seam exposed at the time of my visit averaged 10-18
inches thick. The swath of coal exposed while I was there was
not over 00 yards long. In this area of mining, the Bevler
seam Is only 12-15 feet below the surface and the old pits are
covered Just about as fast as the coal Is removed. Unfortu-
nately, the urea excised was exceptionally clcuu of coal halls.
The descriptions of Mr. Compton and three men who were work-
ing on the stripping shovel all tallied and agree that the coal
balls tend to occur in pockets with u center of greatest density
or abundance with gradually diminishing numbers towards the
borders of the area. In the lft-18 Inch seam they tend to
occupy the entire seam from top to bottom in the ]KH.-ket areas,
the coal present being reduced to an embedding matrix. Just
t»efore we had arrived, the stripping shovel hit a small pocket
occupying the entire thickness of the seam and had put the
whole shovelful up on the far side of the pit. Snmples of coal
balls from this are ladng sent you. It was quite evident to
me, from an examination of the almost Intact shoveful, that
the coal balls Imd filled the whole seam in that s]K>t. There
was a veneer of coal on all the coal ball material, but 90 jiercent
of the shovelful was "rock."

Shortly after looking over the above, the stripping shovel
ex is wed a large flat coal ball in place In the face of the seam
with at least an Inch of coal above it. A rounded, almost pure
pyrlte coal bull occurred slightly below It. deei>er In the coal.
Several pictures of the above exposure are enclosed and the
two coul balls are being sent you.

Accordingly one can definitely say that these "coal balls" are
abundant In the Ilevier coal, usually in localized nreas where
they almost fill the seam, or in more Isolated cases where they
tend to occur In the upper pnrt of the seam.

Regarding the underlying bed, Baxter wrote :

The coal seam lies on what I would consider a typical stlg-
marinn underclay. Mr. Compton had the stripping shovel dig
down Into it for several feet. • • • Mr. Compton said the clay
varied In thickness from up to 12 feet down to less than a foot
thick, overlying a limestone layer. The depth of clay at the
region of the picture was certainly over 3 feet.

Baxter observed that “none of the coal balls I saw,
either in the pit or on the older dumps showed any-
thing I could identify as plant material.” He further
stated :

While as indicated below, there is no doubt about the rather
highly pyrltizcd rock from this mine being coal hall materlul,
in that it definitely occurs In the coal itself, it still seems quite

different from most coul balls 1 am familiar with. For one
thing, most of the rocks tend to occur as fiat sheets. 2 to 3
inches thick. This makes it l<K>k suspiciously like similar
fosslllferous rock from the overlying shale. However, there
is no doubt that this occurs within the coal. 1 There is a
smaller percentage of slightly rounded coul balls which utmost
always seem to be neurly pure pyrite.

In September 1957, Mamay revisited the Apex-
Compton mine but made no significant additional
observations, except that the overburden then exjjosed
contained no fossiliferous rock with which the faunal
coal halls could be compared.

Fauna) coal halls were found at only one other local-
ity, this being a small strip pit in the Ilevier coal, owned
by the Garrett Coal Co. and located in S K. 14 sec. 34,
T. 26 S., R. 25 E., Bourbon County, Kans. At this
pit a few highly pyritized faunal coal balls were found
in the uppermost 3 inches of the coni, which was about
18 inches thick. None were seen elsewhere in the seam,
nor were any normal coal balls found.

PHYSICAL AND BIOLOGICAL FEATURES OF COAL BALLS
NORMAL COAL BALLS

The characteristics of normal coal balls were discus-
sed thoroughly by Slopes and Watson (1908). A few
comments are added here for the sake of completeness.

Normal coal balls show considerable range in the
variety and preservation of their content, the quality of
preservation being dependent on high percentages of
calcium carbonate. Some contain little but roots or
lycopodinean periderm, while others are rich in leaves
and reproductive organs. A large number of samples
from a given locality may give the investigator a rea-
sonably sound basis for analysis of the local flora in
terms of dominant and snbdominant species.

Occasionally one finds a coal ball that consists of a
single plant fragment. At the West Mineral locality,
Mamay lias found several well-preserved calcareous
lycopod, medullosan, or psaronean stem fragments a
foot or more long, surrounded by a film of coal and
unaccompanied by other plant debris. The same local-
ity yields large numbers of tiny “micellar coal balls”
(Roth, 1956), each of which consist of the internal
parts of a single cordaitean seed.

Normal coal balls vary considerably in shape, some
being nearly spherical. Specimens of this type seem
to be most common in the English de]>osits hut are rare
in American deposits.

The contents of spheroidal coal balls usually show
no layering or other textural peculiarities. Most com-

• Stopes «n<l Watson reported apparently similarly shaped sheets of
stone In the Knclish eonls ; however, they considered the stone sheets*,
which they discussed only briefly mid which contalu only plant mate*
rial, to be a “parallel formation to that of the uormul coal bulls*'
(Slopes and Watson. 1908, p. 176).

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

monly the plant fragments are uncompressed and other-
wise undistorted.

Lenticular coal halls are common in American
deposits. All degrees of lenticularity may be found,
the most extreme having perhaps a ratio of less than
one-quarter thickness to width. Some specimens are
nearly circular in outline, relatively smooth-surfaced,
and often slickensided. Coal balls of this type are
common at the West Mineral, Kails., locality, some
being nearly 2 feet in diameter. A West Mineral nor-
mal coal ball, irregular in shape but typical in composi-
tion, is shown diagrammatically in figure 43. and a
lenticular specimen is illustrated on plate 28, figure 2.

Lenticularity is assumed to lie the result of prelithifi-
cation compaction, for lenticular sjiecimens in place lie
parallel to the bedding of the coal, with the laminae
of the coal following the contours of the coal ball. This
type of coal ball also presents the greatest consistency
of relation of external shape to internal texture, for
lenticular coal balls generally show distinct layering
of the enclosed plant parts, the layering being almost
parallel to the bedding of the coal. Stems with large
or hollow pith cavities, such as the calamarians, are
commonly flattened in lenticular coal balls. Further-
more. coal balls of this type commonly have a thin
equatorial flange of well-preserved plant material that
feathers out and disappears bet ween laminae of the coal.

Aside from the spheroidal and the lenticular types
of coal balls, there are no other regular or definable
shapes that characterize these nodules. Coal balls
have a variety of irregular shapes; angular external
contours are, however, extremely rare. Specimens of

203

irregular shape may show bedding or layering of their
contents, but, on the other hand, commonly there is no
definite arrangement of plant debris in the matrix.

Cnlcite- filled cracks, often penetrating nearly the
entire width of a specimen, and concretionary minerali-
zation patterns are common to all types of coal balls
discussed thus far. Cracks may be abundant in a single
specimen, and sometimes they fall into a roughly radial
pattern that extends inward a variable distance from
the periphery of the nodule. That such cracks often
create a clean break in an otherwise undistorted and
well-preserved plant axis suggests that they are proba-
bly compaction cracks, formed after initial minerali-
zation had been completed.

HOMOGENEOUS-MIXED COAL BALLS

Homogeneous-mixed coal balls are mostly irregular
in shape, although lent icular specimens have also been
seen. Some homogeneous-mixed balls are slightly
flattened, with layered alinement of the enclosed fossils,
and in the lenticular specimens layering of fossils may
be as clear as that often shown by plant debris in the
lenticular normal coal balls. Calcite-filled cracks are
common in homogeneous-mixed coal balls. A homo-
geneous-mixed coal ball is shown diagrammatically in
figure 44 and others are illustrated on plates 27-29.

Animal and plant fossils may be randomly scattered
through the entire coal ball, but in some the animals
seem to be concentrated in poorly defined pockets. In
samples of this sort the animal-containing pockets may
be distinguished from the remainder of the coal ball
by a slight difference in the color of the matrix, which

Figuiik -13. Sketch of miwii surface of n normal coni hall from West Mineral. Kuub.,
drawn from a peel preparation of specimen 01$1> (*1E. Calcite-ttlled crucks are
unstlppled. Approximately ‘*io natural size.

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204

SHORTER CONTRIBUTION'S TO GENERAL GEOLOGY

Flock* 44. — Sketch of sowed surface of a homogeneous-mixed coal ball from West Mineral, Kana., drawn from a peel
preparation of specimen 9189-120A. Unsttppled areas represent animal remains. Natural else.

is not, however, sharply delineated from the surround-
ing matrix. Mixed coal balls with pockets of this type
( may also contain faunal and floral mixtures in other
parts of the specimen.

Some homogeneous-mixed coal balls show a peculiar
textural feature that is like the mixing together of two
colors of cake batter and that we refer to as “swirled.”
This “swirling” consists of oriented lines of animal
fossils. The lines nearly parallel each other, but are
very irregular and bear no delinite relation to the
bedding plane of the coal where that feature can be
inferred from the shape of the coal ball or adherent
remnants of the surrounding coal. The swirl markings
may also assume roughly concentric orientation, and
may intergrade imperceptibly into coal ball matrix that
shows no structure.

HETEROGENEOUS-MIXED COAL BALLS

Heterogeneous-mixed coal balls, which have been
found only at Berryville, III., differ from all other types
by showing a segregation of marine from nonmarine
parts of the matrix; this segregation is illustrated in
figure 45. Actually, this is not a simple segregation of
plant from animals remains, for a certain amount of
small resistant plant fragments (mostly well-preserved
spores) is incorporated in the animal-containing matrix.
However, this animal-containing matrix is surrounded
by an area that contains only plant material and that
in all aspects is typical of the matrix of a normal coal
ball.

The marine masses, to which for want of a better term
we refer as “cores,” are of much interest, both structu-
rally and biologically. They vary in form from elon-
gate, more or less cylindrical rods that extend through
the entire length of the coal ball, to irregularly shaped
cores. The cylindroid type of marine core is illustrated
in figure 45 ; others are shown on plates 30 and 31.

In the example shown in figure 45, as well as in
several other examples, the coal ball is an elongate,
slightly flattened specimen. The plant material shows
perceptible flattening parallel to the long axis of the
specimen. The marine core, which is slightly eccentric
in position, extends through the whole length of the
coal ball (approximately 10 inches) and is exposed at
either end. It varies little in either its diameter (ap-
proximately 2 y 2 inches) or its position relative to the
center of the coal ball, and for the most part displays a
sharp line of contact with the surrounding normal ma-
trix. Here and there, however, a root or stem fragment
or stringer of unrecognizable plant debris crosses the
contact and extends a short distance into the core. In
other specimens, though the contact between the core
and the normal part of the coal ball is relatively clear, it
is irregular and subangular in places.

The figured core is unusual in its deep embedment
within the normal matrix and its nearly perfect cyl-
indroid shape. Other cores are less regularly shaped
and may constitute most of the coal ball. All cores, how-
ever, are surrounded by a layer of normal matrix with-

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

205

Fioi,'*k 4S. — Sketch of lawn surface of a heteroRrnr«u» mlxe«l coat ball, drawn from a pool preparation of s|H*clinrn 0190-2 J.
The marine core la Indicated b>- dark stippling ; calclte-Qlled cracks are unstippled. Natural size.

in a film of coal that indicates their original position
Mow the upper limit of the coal seam.

Marine cores may extend nearly to the bottom of the
seam. A large mass of coal halls, 2 feet long and l foot
thick, was found in place by Mamay in 1957, and dug out
of the coal. The bottom of this mass lay within an inch
of the bottom of the coal seam, and it contains irregu-
larly shaped but distinct cores through its whole thick-
ness. One core reaches the lower surface of the thick-
est part of the coal ball mass, and thus was originally
separated from the underclay by only an inch of coal.

Distinct bedding of the detrital fragments, both plant
and animal, was observed within the marine core in
several specimens. In one core (pi. 30, fig. 1) the fossil
debris is arranged in easily discernible layers. The
bedding may be flat and parallel to the less distinct bed-
ding of the plant material in the surrounding normal
matrix. However, for about 1 cm from the contact
between the core and normal matrix, the bedding of the
core is slightly warped. This warping suggests that the
original lump of marine mud was still fairly plastic
when deposited in the coal swamp. After deposition its
inner bulk sagged slightly and produced the warped
bedding planes.

Our interest in the specimen shown on plate 30 was
increased by two facts: (a) The core itself is a roughlj’
flattened body that stands “on edge” with its bedding
planes extending across its smallest dimension. Thus
the core presumably dropped into a deep but relatively
narrow indentation in the surface of the peat, in such
a way that its own bedding planes paralleled the surface
of the bog. (b) The layer of coal surrounding this
specimen also contains a second small normal coal ball
with distinctly layered plant debris. This layering,
however, is nearly perpendicular to that of the mixed
specimen and indicates a prccoalification disturbance of
the peat, which distoited the bedding plane relations
between these two adjacent coal balls.

The Berryville material is also distinctive because of
its faunal content. As far as determinable, the faunas
of the cores contain several elements identical with ani-
mals found in the limestone overlying the coal seam.
The cores also contain many spores, cuticular frag-
ments, and other plant remains. Although several sam-
ples of normal matrix surrounding the cores were care-
fully trimmed away from the latter and dissolved in
acid, these samples produced no animal remains. It is
therefore evident that the cores and surrounding nor-

206

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

mal matrices could not have been formed under iden-
tical dejjositional conditions. Further support for this
line of reasoning may ho seen in the results of chemical
analyses of the two matrices (p. 207; table 2). These
show that the Berryville core material contains Al,Oa,
which does not occur in the normal matrix or in any of
the coal balls analyzed.

FAUNAL COAL BALLS

Specimens of faunal coal balls were noted in signifi-
cant numbers only at the Monmouth, Kans., locality.
They conform with the essential features of normal coal
balls except that the contained fossils are of exclusively
zoological origin. In shape they vary almost as much
as normal coal balls, but have perhaps a higher propor-
tion of lenticular or flattened specimens. Baxter ( 1957,
written communication) noted that many of them are of
sheetlike aspect. Their faunal contents may be roughly
layered or scattered at random through the matrix,
which may also contain stringers of coal. The animal
remains are mostly small pyritized bracliiopod frag-
ments. As shown in tables 1 and 2, coal balls from this
locality usually contain more pyrite than those from
any other locality investigated.

CHEMICAL ANALYSES

In order to determine what chemical differences exist
between normal and mixed coal balls, eight typical
samples were selected for semiquant it at ive spectro-
scopic analysis and rapid rock analysis as described
by Shapiro and Brannock (1956). The rock analyses
were performed on samples as received, without pre-
liminary drying. Samples of both normal and mixed
coal balls were taken from West Mineral, Kans.,
McAlester, Okla., and Berryville, 111.; a faunal coal

Imll from Monmouth, Kans., was analyzed. The Berry-
ville material also included one sample from a hetero-
geneous-mixed coal ball and a piece of the limestone
over the channel in the coal seam.

The rapid rock analyses (table 2) show some
apparently consistent but small differences between
normal and mixed coal balls in concentrations of SiO„
FeSj, IUO, P 2 0 5 , A1,0„ CaCO, (CaO+CO : ) and
MgO. These could reflect chemical makeup of animal
fragments or other uncontrollable factors, and cannot
safely be considered significant. The complete results
are, however, presented as tables 1 and 2, for they
represent the most detailed coal ball analyses known
to us.

In reviewing the published record we found several
chemical analyses of coal balls in papers treating pri-
marily of the fossil floras. References to these are
given to aid t host' who may wish to pursue the problem
of the formation and chemical composition of coal
balls. Analyses published prior to 1908 were summa-
rized by Stopes and Watson (1908). An analysis of
a single coal ball from Bohemia was presented by
Kubart (1911, p. 1038). Leclercq (1925, p. 21) pub-
lished one analysis of a coal ball from Belgium and
subsequently analyses of three others (Leclercq 1952,
p. 398). Zalessky and Tchirkova (1931, p. 590) pub-
lished an analysis of a coal ball from the Kousnetzk
basin of Russia. Teichmuller, Teichmiiller, and Wer-
ner (1953, p. 145) published a summary of their work
and that of others: they listed a dozen analyses for
iron oxide, calcium carbonate, and magnesium carbonate
in coal balls or “Torfdolomit" from the Ruhr area of
Germany. So far as is known, Darrali (1939, p. 132)
has presented the only published analysis of a coal ball
from the United States.

Tabi.e l.—8cmiqnant(tative spectroscopic analyses of coal ball and limestone samples

(Anolyjttx: Mona Frank and P. L. D. F.lmore. Phosphorus may be present in the«* camples, but further work is ncerewnry to assure positive identification. Sensitivity for

phosphorus tsO.t]

Percentage

W«t Mineral, Kans..
Fleming coal

Benyvlllc, III., Calhoun cool

McAlester, Okla., Secor coal

Monmouth,
Kuna.,
Bevier cool

Sample 145717.
normal
coal ball

Sample 145718,
mixed
cool bull

Sum pie 145710,
normal
coal bull

Sample HAT20,
marine one from
lulled cold ball

Sample 145731.
murine limestone
above ouul

Sample 145722,
normal
coal bull

Sample M5723.
mixed
coal troll

Sample 145724,
faunal
coal hall

>10

5-U)

1-5

Fc. Mg

F«

Al. Mn
Sr. V, Xa. TI

B, Nl
Pb. Cu, Bo
Cr. Mo

Mg
Al, Fo
Si. Mn
Sr. Xa
Ba. TI, V

B, X I
Cr

Cu. Mo
Ag

Fc. Mg

Fo
Mg
SI, Al
Mn

11a, Sr, Na. V
B, Ti

Cr, Mo. Cu

.5-1

Fc. Mg

Xa. Sr. Al

TI. B. Nl
V. Ba
Mo, Cr. Cu

Fe, Mg
Si. Al

Sr. Xa. Mn
Ba. Ti. V, B

Pb. Cr. Cu. Mo

.1-.5

.05-. 1

01-.05

.005- .01

.00) -.005

.0005-. 001

.0001-. 0005

SI, Mn
Al

V, Sr, Xa, B, Ti

Nl. Pb
Ba, Mo
Cr, Cii

Su Al. Mn. Na.
H

Ba, Ti
Cr, Mo, Cu

SI. Mg
Al

Mn. Na, Sr, Ba,
Pb

Cu, V. V
Mo. Sn. Ti. Zr
Yb. Cr

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

207

Tabus 2. — Rapid rock analyses of coal ball and limestone samples

[Analyat: Paul W. Scott)

Conatltueot

W«t Mineral, Ka ns.,
Fleming coal

BenyvlUe, 111., Calboun cool

McAlester, Okla., Secor coal

Monmouth,
Kane.,
Bevler coal

Sample 145717.
normal coal
ball

Sample 146718.
mixed coal
tell

Sample 146710,
normal octal

ten

giunple 145720.
marine core
from mixed
coal boll

Sample 146721,
mar too
limestone
above octal

Sample 148722,
normal coal
ball

Sample 148723,
mixed coal
boll

Sample 148724,
faunal coal
ball

810,

0.21

0.80

a*6

1.8

2.9
1. 1

0.31

1.3

.46

1.1

> FeO

i.3

i.o

2.7

2.2

MgO

2.8

1.0

1.8

1.4

2.8

3.4

2.3

.40

CaO

47.6

45.9

51.6

50.2

411.0

48.4

45.8

18.6

NaiO

.00

.08

. 14

.10

.08

.13

K,0

.01

.03

. 15

TIO,

.01

.02

.CO

.04

.02

.01

PiO,

. 10

.08

.23

.17

. 16

.1#

.51

MnO

.34

. 18

.27

. 18

.47

. 18

.05

HiO

.73

.50

.78

1.2

.62

.ws

CO*

40. 5

37. 1

42.4

40.4

40.2

40.8

30.7

14.5

Total S as FeSi

4.6

11.2

.60

3.0

1.0

1.8

4.7

60.9

Total •

‘ Iron, exclusive of that required for calculation of FeSi, calculated as FcO.

> Organic matter contained In all samples may account for differences between totals and 100 percent.

LABORATORY METHODS

Mixed coal balls from each of the various localities
possess more or less distinctive physical and biological
characteristics. To demonstrate these differences, a
number of coal balls, as well as samples of associated
rocks are described on pages 217-222. Faunal contents
of the samples and spore identifications are summarized
in table 3. Although small isospores or microspores
were observed and are apparently abundant in some of
the residues, these were not identified, becauso the larger
spores were sufficient demonstration of the intermixture
of land plants with marine animals.

Though animal remains in coal balls may easily be
seen on cut or broken surfaces, such examination gives
a generally incomplete picture of the biological com-
position of the assemblage. For this reason acid solu-
tion was used as the chief technicpie for releasing fossils
from the coal-ball matrix.

When animal remains were first noted in the collec-
tion briefly described in 1953, commercial grade hydro-
chloric acid was used to isolate pyritized remains from
the matrix. However, the diversity of animal groups
represented in these residues suggested the presence of
phosphatic fossils such as vertebrate bones, teeth and
scales, and conodonts. Formic acid therefore was
substituted for hydrochloric in our later studies, with
the result that phosphatic fossils were recovered from
many of the mixed coal balls.

Coal balls selected for acid solution were sawed into
1-inch thick slices; part of each coal ball was held in
reserve for additional preparations if later desired.
Because most of the fossils seen on the smoothed sur-
faces were relatively small, the slabs selected for acid
solution were broken into small pieces to speed the re-
action. Where it was evident that lurger fossils were

662661 0—62 4

contained in the matrix, entire slabs were dissolved.
Before the cores of marine sediment in the Berryville,
111., coal balls were dissolved, surrounding normal parts
were trimmed from the core so that the insoluble resi-
due would not be contaminated with plant material
from the normal coal ball matrix.

The samples were then weighed and placed in formic
acid in covered containers. Strength of the acid was
adjusted to prevent effervescence from damaging fragile
specimens, and was maintained by daily recharging of
the solution. Most samples required 7 to 10 days for
complete solution of thoir soluble components. Sam-
ples high in calcium carbonate were generally reduced to
fine- or medium-textured granular residues, but some
with large amounts of pyrite were deeply corroded
but not entirely disaggregated. The latter contributed
little to faunal analyses because of generally poor pres-
ervation of the fossils.

The residues were washed in water, allowed to dry,
and weighed to determine the proportions of soluble
and insoluble components of the original sample. The
residues were then sized through standard-size sieves
down to 200-mesh size; this was done under water to
keep breakage at a minimum. The graded residues
were then dried and picked. In addition to the mixed
coal balls, samples of limestone caprock, of normal coal
balls, and of the normal matrix surrounding cores in the
Berryville, 111., specimens were also dissolved.

Samples from Berryville, 111., were the most soluble:
their residues ranged only from 0.2 to 5.4 percent of
original sample weight. At the other extreme, residues
of samples from Monmouth, Ivans., ranged from 22.6
to 37.9 percent of sample weight. Because the solu-
bility of the different samples showed meaningless vari-
ation, further details are omitted.

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208

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Tabu: 3. — Distribution of animal groups and large spores in insoluble residues

Samples 9189-1 19 and 8190-1 were not etched In order to preserve calcareous coral
specimens.

Locality of samples: E-1,2. 17, Franklin, Kans: *189-1 19. E-9. 10. 12, 18, 23.21, West
Mineral, Kam.; E-7, 8, 20, 21. Monmouth, Kuns.; E-ll, 22, 30, 31, McAlester,

Okla.; £-13, Osksloors, Iowa; E-3, r. 19, 24-29. 9190-1. Berryvllle. ni.: E-14, lime-
stone overburden. West Mineral, Karts.: E-18, limestone overburden, McAlester,
Okla; E-6, limestone In channel, Berryvllle, 111.; E-ri, limestone overburden,
licrryvlllc, III.; E-1S, limestone below channel, Berryvllle, 111.

Type id depoelt and Sample mini her

Posen

PlCtOOJH

AmtunrUlM Ineluta C ashman Mid Waters.

AmmsstrUUs ef. A. Mbttlnls* Ireland

AmnsnrUUst sS. I. prttHtolit Irelsnd

A ismortrute to

nr Strpuhpm sp..

Ammamlrlte'’ tp..., .

or fifomotpira sp

0*nt» df. .-ImmmerrrCa

Apterritirlh sp,...,

or ChUitGTKelh sp.

Aehrrlmlit *p.

dmutpittl sp

or CTommf/ira sp ...

Cbraaspfra? sp

J'mfsttjM er fiadoOyrsncffs? sp

Eudstlimutta po until (Her lot on). ...

sp -

OMktttltulins sp...

Wmm <p.

Bnpulepttt off. 8 . IhMte (White) .

SapubinUt sp. .

TtfnUiU napnlit (Worlhtn)

Tftaromeimo tiff. T ttelenfvlarU Ireland.

»»V

TkoroaurrhioMrs sp......

PosnlliiMs iitdc!

Portfera:

Cl FUtltpau/bl sp

lli-v«tl:ic!IM spicule

Coden terete:

Lopbopbyllld eond

EcWnodcrmata:

Crlmrid stem*,.

Annelida:

AtttfriHiUt *p

"SpimbW’tp

Brroaoo:

AirsSporeJtesp .

Trepostomatoos b ryot cans ladet

FmtktiMs sp

Polsporttp l......

sp 2

Sp 3

Ftamrflepam tp I

sp2.

Stp!m>rt> sp.

KuWomtaotrap ,

Momtocledfaep.. ...........

Itho miepom jp

Bnfchlorcda

UntuloM tridel.....

Orblmloid I rate i .

Btlpliamdlsl sp ,
JMt/iyia sp

JI/raN«ta«ep- .
Chonetld Indet

Ma'oiiUftrt rap

rroduetold Indet

olollnseit:

MumliBrsp.

Nooitold imlet

ParalMoiau sp

8tp)lnptlh<a sp

Cl UitipUH o sp

SAkluduttp

A tbvkptrtra tp , , .

Peel it old Indet .......

MytIHd Indet

i '• - piopdanrf «p.

AttMHk Sp

Pctecypor * undH

rclecypod* Indet

Ksfesitm iRtiupino sp

Bellcropbonttd Indci , -

fktrtstttt sp. .

Glabrednestaa sp,

S r til«mhi sp

UStuAtUa tp

Stciokern ef SunuUUs

PHirotoinartan Indet..

Cl, jVferodome sp

Fucvthllt sp...

Homopneens-iaincd eeal ball*

Heteroaeaeoua- mixed
coal balls

Normal cool balls

! Penn-
si
eutl
tr.dl«

MtsoeUaaeoua

associated

md tmeo cary
depoait*

=■-

C*.

<9t

: S

■

...

X i

... 1 ...

...

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

209

Table 3 . — Distribution of animal groups and large spores in insoluble residues — •Continued

Type 0 / deposit snd sample number

Fossil

Bomofeneoue-mlnel call balls

BeleronoMUf-mlnd
cent bells

Normal co.nl balls

Faun

rml

b*Uy

M isoe Hensons
associated
mtliDmtm
depsssSIs

Sfl

fcs

5*J

’C

tiS

MoBlW Cflptfamd

BaiSfod tades.. ........ ......................

| X

j X

A/thropodi:

' X

1 Y

odchcnw.viw HajUob-

;iff. "B.” tar,m HarlKm. . .. -

Htnldm™ .. .......

SeituubJhl

Avij’lmrittr eenhuutfnr (UlrScJj an<1 Hsssh's)....

klikttburt $p„ ...... . .......

tiSmiu m> ............ ..... ...............

Otoa* liKkUs... » * * * . * * v . , , . . * . ,

Chordata:

ACfttitbodiL.... , v .

CMoldadiB

Sotoftii

Plan rocKDiboldU *

ArUo0t^|1l.

C< oodants:

J tmdraititta sp

Omrliut i.-, itiiCiVtla tSUwifier atm! Pht dunes) , ,

OurMiM p

.Sfftyiivknth* *|i ..... ... ......... ............

JtaHudf* ci h sttbatsda (Gunnell)

9patteps«tMw mtautssf ;8tlUoo>

( a'osirHelAu) f'.rsc Edison ...... .

WHtnifitM Stauffer mad Plutatnex

cf. / mmmnifitu* ind P 1UCJ trier . .

AnpfifNMi (taonlu/iu Btauffo &nU
Puraffler . ... v*.

Huttke oonodoot todet. ... .

Pbric^iki conodcmt irudet. ..... ......

L»m? »{***»

CyiUnpvritt* rarfvt (Wieh*0 Dljkatra,.,.

...... . . .

Mwwteu i status Scbopr. .

FataspotHts cf. msetaM Schopf

TiiUt*# mb tftm Zdmdt . ...............

cf.

«&6rc/a4

cf. T. npodw Benkrtt...

£rim&jp*imsm Z«radi..».

sp.. ......

Lmt ipm MMWbilMi Ipmpsia.

•

■

••

• S|*cimen» probably nonspecific, hut no! complete enough lot positive blemllleitlon.

210

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The technique described allows recovery of all but
calcareous specimens. In order that important faunal
elements should not be overlooked, non pyritic speci-
mens exposed on fractured surfaces were prepared
for identification by mechanical methods. Most of
the animal remains recovered by this method are py-
ritized; the calcareous ones constitute a minor element
and consist largely of brachiopods and crinoid colum-
nals.

It is probable that some specimens were destroyed
or escaped observation during preparation. Neverthe-
less a sufficiently wide variety of animal groups are
repeated in several coal balls from the same locality to
favor the probability that most of the faunal elements
are known.

PRESERVATION OF THE FOSSILS

Preservation of the plant fossils needs littlo dis-
cussion because, ns is usual in coal ball petrification,
there is little if any replacement of the original sub-
stance of cell walls. Woody tissues owe their excellent
preservation to an impregnation and filling of the cell
interiors, the dominant impregrating material usually
being calcite. Waxy spore coats and cuticles, among
the most resistant substances in the plnnt kingdom, are
ordinarily preserved practically unchanged.

Most of the megaspores recovered from the acid
residues are so little distorted bv compression that their
original shapes and external morphological features
may be satisfactorily studied (pi. 33). Those from
Berryville, 111. (pi. 33, fig. 17), Me A tester, Okla., and
Oskaloosa, Iowa, are seen to be hollow when their coats
are broken, a condition that we ascribe to dissolution of
the original calcareous fillings of the spore envities dur-
ing treatment with acid. Megaspores from West-
Mineral, Kans., however, may lie recovered in a hollow
condition or their interiors may contain mineral
fillings, usually calcitic, rarely pyritic (pi. 33, figs. 8,
9). The fact that some of the calcitic fillings remained
intact after several days' treatment with acid can only
be due to exclusion of the acid from contact with the
surfaces of the tilling, by the intact and impervious
endosporal membrane or exospore, or by lxith. Speci-
mens of Trihtes cf. T. superb us recovered from the
same coal ball were either hollow or were filled with
pyrite or calcite.

Some of the megaspores are so well preserved that-
their endosporal membranes can be dissected out.
Membranes removed from specimens of Tritetes cf. T.
snpcrbm are thin and delicate, and almost invariably
show a pattern of regularly distributed and shaped dark
spots (pi. 33, fig. 10). The spots, which may represent
vestiges of cellular organization, are always restricted

to the proximal part of the membrane, and more con-
cisely, to the circular area that is delimited by the
arcuate ridges connecting termini of the triradiate
sutures of the exospore. On the basis of their proximal
positions these spots, despite their abundance in any
one spore, were first interpreted as the remains of
archegonia, but perhaps they are equivalent to the
papillae in similar membranes of Duosporites described
by H0eg, IJose, and Manum (1955).

Animal remains from most localities are generally
replaced by pyrite, but preservation may also be cal-
careous, phosphatic, or baritic. Only in conodonts,
scolecodonts, and fish is evidence of replacement lacking.
Both conodonts and fish parts are phosphatic. The
few scolecodonts found are black, highly lustrous, and
resistant to all the common acids. They nre apparent ly
the original chitinlike substance.

Five other groups — the bryozoans, ostracodes, trilo-
bites, worm tubes, and sponges — are consistently pre-
served in pyrite, almost invariably by replacement, but
the few corals found remain calcareous. In the pyritic
specimens, replacement ranges from fine to coarse
grained.

Preservation of foraminifers is siliceous or pyritic.
The thuramminids and tolypamminids had hard ag-
glutinate shells, and in the acid residue the silica sand
of many shells remains coherent because of silica cement
which may be of secondary origin. The globivalu-
linids, originally calcareous, were not noted in other
than pyritic preservation or chamber fillings. The
fusulinid shells are mostly unaltered but their chamber
fillings are pyritized or partly silicified.

Aside from the linguloids and orbiculoids, which are
phosphatic and do not appear to be replaced, brachio-
pods from the West Mineral. Kans., samples are un-
altered and require mechanical preparation ; a few are,
however, preserved in pyrite. All those from Mon-
mouth, on the other hand, are pyritized.

Mollusks are present in all the faunas investigated.
Pelecypods and gastropods are conspicuous faunal
elements. The pelecyiiods, with two exceptions, are
preserved only in pyrite. Cephalopods are calcareous
except for the figured specimen (pi. 34, fig. 29). Min-
eralogic composition of this one was not determined
because to do so would necessitate destroying part of the
specimen. The specimen is insoluble in hydrochloric
acid.

Preservation of the gastropods is perplexing. Al-
though specific identifications are difficult because of
the quality of the preservation, there is no apparent cor-
relation between biological identity and mode of pre-
servation of the gastropods. They may be preserved as
actual shell replacements or as steinkerns ; steinkern

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

211

preservation of some pelecypods and foraminifers has
l>een seen but not of the other animals observed. Stein-
kerns may be phosphatic or pyritic and may fill cal-
careous shells, as shown by hollow casts surrounding the
steinkerns on etched surfaces. Shell replacements are
pyritic and filled with calcareous material, as shown by
the hollow interiors of shell replacements recovered
from the residues. Pyritic replacements are most com-
mon, but in one sample (Monmouth, Kans., E-20) re-
placements are composed of barite. A single coal ball
may yield different individuals certainly of generic and
probably of specific identity in all the types of preser-
vation noted.

One further point with regard to the animal remains
deserves mention here— the size of fragments or whole
specimens, exclusive of those of ostracodes and cono-
donts. With the occasional exception of Derbyia and
productoid brachiopod shells which may reach 3 cm or
more in width, most of the animal material consists
either of complete individuals or of fragments smaller
than 1 cm in maximum measurement; more than half
are 0.5 cm or less.

It is probable that mechanical sorting by wave or
current action before original sedimentation and sub-
sequent translocation to the swamp is the explanation
for the consistently small size of animal fossils found
in the coal balls and that the residues are not a repre-
sentative sample of typical Pennsylvanian marine
faunas.

Few of the specimens show evidence of abrasion or
mechanical wear, and some of the more intricately orna-
mented ostracode shells are perfectly preserved. The
one group in which worn specimens are common are
the fish remains. The rounded comers and edges of
many scales and dermal plates suggest considerable
abrasion before final deposition.

Representative suites of plant and animal remains
recovered from the acid residues are shown in plates
33 and 34, respectively. Plant material was photo-
graphed as recovered from the residues, without further
chemical treatment.

INTERPRETATION OF ANIMAL-CONTAINING COAL
BALLS

Because the marine animal remains contained in the
mixed and faunal coal balls cannot be regarded as in-
digenous to the coal swamps, a fundamental conflict with
commonly accepted theories of coal ball formation
arises. Normal coal balls are considered by most au-
thors to represent concretions formed in place, in ac-
cord with the conclusions of Stopcs and Watson (1908).
At variance with that hypothesis, however, Kindle
(1934) preferred to compare coal balls with the so-

called lake balls — mechanically accretionary, spheroi-
dal masses of plant material whose formation has been
observed in Recent, aquatic environments. Kindle’s
analogy has not met with popular acceptance (Schopf,
1949, p. 81), but it is possible that his explanation may
contain some acceptable points if applied to mixed coal
balls. Obviously, any explanation of marine organisms
in nonmarine strata must involve transportation of
material. Rafting of coals has been suggested in ex-
planation of the phenomena described here, but this
explanation is highly improbable in view of the other-
wise normal sedimentary relations of the coal seams
that provided the mixed assemblages.

Some coal seams locally contain exotic materials
such as igneous boulders and pebbles, and although
these attract much interest, there seems to be no agree-
ment regarding the mechanisms responsible for such
inclusions; cataclysmic transportation, however, is a
frequently suggested mechanism. The following dis-
cussion by Whitehead and others (1952, p. 290) demon-
strates the necessity for resorting to unusual deposi-
tional circumstances by way of explanation.

W. L. Whitehead : A 15- or 20-foot tidal wave Is not uncom-
mon on some coasts during hurricanes or tsunamis. At these
times submarine plants with hold-fasts can carry a 0-inch
boulder 10 miles.

J. M. Schopf: Well, that certainly Is a possibility. I should
sny that, a number of these freakish and very dlffleult-to-ex-
pluin occurrences must he explained hy some cataclysmic
method of the sort. 1 am not at all sure that the widespread
partings aren't in that category too.

I. A. Breger: Shouldn't you get occasionally some marine
evidence?

J. M. Schopf : Yon would think so — but let me tell you of an
occurrence which puts the “shoe on the other foot.” I have
found coal-hall limestone, that is. the limestone characteristic
of coal halls which must have originated no higher than within
the upi>er portion of a coal-measures ]>ent deimsit — such coal-
hall limestone has been found embedded in an unquestionable
marine coquina overlying the coal. This is an example of the
reverse direction in transportation. The eonl-bnl! limestone
must have originated within the precoal peat bed and then have
been transported liodily into the marine hed aliove it. There
are some strange things associated with coal.

We regard the animal-containing coal balls as repre-
sentative of the “marine evidence” sought by Breger.

HETEROGENEOUS-MIXED COAL BALLS

The Berry ville cores or marine inclusions are con-
sidered best explained by a transitory force (hat intro-
duced them into the accumulating peaty plant debris.
The evidence for this hypothesis is the complete
embedment of the inclusions within the coal balls,
apparently without interruption of coal deposition.
The following possible physical setting and sequence

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212

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

of events is visualized in explanation of the origin of
the cores:

The coal swamp lay at or near sea level and was
perhaps separated from the sea only by a low narrow
strand barrier, which was sufficiently high to prevent
access of marine waters to the swamp environment
through normal tidal action. Offshore in shallow
waters, a calcareous mud was accumulating, into which
both marine animals and bits of plant material, either
windblown or drifted, were being incorporated. The
animal remains, as demonstrated by their consistently
small size, were probably being transported from far-
ther offshore sites of original deposition by currents,
the larger representatives of the fauna being sorted
out during transportation and only rarely being
brought landward, or being brought in only as smaller
fragments.

As previously mentioned, each insoluble residue of
Berryville core material contains many spores, bits of
wood, cuticles, and other plant parts. Except for the
spores, many of which are complete and undistorted,
the plant material is fragmentary. If the cores do
represent transported samples of the sea bottom, then
the plant debris included in the cores represents a part
of the original organic constituents of the marine mud,
and as such must be interpreted as twice-transported
matter. The plant material may have been blown to
sea by the wind or may have drifted out on the surface;
eventually it became waterlogged and sank to the
bottom to intermingle with the accumulating animal
debris. As the spore contents decayed, the spore in-
teriors were filled with minerals, so that they underwent
little or no compression before final calcareous cemen-
tation. Finally, the plant material was transported
back to the coal swamp, perhaps coming to rest many
miles from the area in which it had originally been
produced. However, it may also be that a short dis-
tance, as well as a short tune lapse, for both translo-
cations was involved, because some of the most con-
spicuous spores in the core material ( Triletes gldbratvs,
T. auritus var. grand is, and Monohtes ovatxis) also occur
abundantly in the normal coal balls from this locality.

Occasionally lumps of the semiconsol idated mud
were dislodged from the sea floor by tidal currents or
by other relatively minor disturbances and were worn
into various shapes by wave action ; some of these lumps
assumed cylindroid shapes, some were more irregular.

Violent storms created unusually large waves that
swept inland and inundated the swamp. The waves
carried along the cylindroid wave rollers as well as
less regularly shaped lumps of mud that contained
both animal and plant remains. The mud lumps were
deposited on the irregular surface of the peat, or fell

through the upper layers. A firm consistency of the
mud lumps is implied by the discrete nature of the
cores and the angularity of some of the cross sections.
However, parts of the mud lumps were sufficiently
soft that intermixture with the adjacent peat occurred
locally, and some of the firmer plant fragments pene-
trated the surfaces of the lumps.

The core shown in figure 45 is oriented parallel to the
mass of roots that constitutes the normal matrix. The
roots, preponderantly alined in the same direction,
probably created a series of nearly parallel grooves
on the surface of the peat, and minor agitation of the
receding water could have caused the core to settle in
one of the grooves. Meanwhile the turbulence also dis-
lodged chunks of peat, redeposited them, and in some
instances effected a reorientation of their original bed-
ding planes. Evidence for this reorientation is appar-
ent in the specimen shown in plate 30, figure 1, where
the bedding of plant material in the small coal ball
fragment within the coal matrix at the right is oriented
nearly at right angles to that of the larger specimen
containing the marine core. The same specimen shows
evidence that deposition of the marine material was
sudden, rather than gradual and protracted, for the
plant material beneath the lump is compacted and
bedded parallel to the rounded contours of the bottom
of the lump, while the plant material in contact with
the sides of the lump shows evidence of shearing.

Marine waters soon retreated. Upon restoration of
the normal swamp environment, continued peat deposi-
tion covered the foreign marine mud-lumps and en-
closed them within the plant debris.

Lithification of the mixed coal balls, just as of nor-
mal ones, preceded final compaction and coalification
of the peat, as demonstrated by the direction of lamina-
tion of the coal in relation to layering in the hetero-
geneous-mixed coal balls and by the uncompressed
condition of material within the coal balls. Concre-
tionary action was probably responsible for calcareous
preservation of plant debris and its cementation to the
marine core.

While the summary above possibly represents an
oversimplification of events, we believe that it best fits
the evidence on hand.

In seeking to explain the slender cylindroid forms
of some of the Berryville cores, let us consider an
analogous modern erosional phenomenon. Along the
western shore of Chesapeake Bay in Maryland are steep
cliffs of the Miocene Calvert formation, including beds
of blue clay. In the area south of Chesapeake Beach,
large blocks of the clay occasionally slump into the
water. Wave action erodes these blocks into smaller
lumps, some of which eventually are thrown onto the

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

213

beach. Among these lumps some specimens are worn
into long, roughly cylindroidal shapes. One, collected
in 1952 by Jack E. Smedley, is a straight rodlike lump, 8
inches long, IV 2 inches wide, and V6 inch thick, with an
oval cross section; its width and thickness are nearly
uniform, and it is abruptly rounded at either end. This
rod is similar in shape to the core illustrated in plate
31, figure 1.

Occurrences of similar clay balls and boulders were
reported by Grabau (1913, p. 711-712) and by Richter
(1926). They reported the boulders to have been
formed under water and sometimes to be encrusted with
marine shells that became embedded as the balls rolled
over shell-containing sands. The “schlickgerolle” ob-
served by Richter on the coast of the North Sea are
sometimes cylindroid.

Analogous modern sedimentary material has been
reported in several recent papers. Armored mud balls,
described from Ventura County, Calif. (Bell, 1910),
provide a striking example of the effects of currents
in abrading chunks of mud into symmetrical forms;
many observed by Bell were nearly spherical in shape.
The armor of these balls, although consisting chiefly
of pebbles, illustrates the ability of rolling mud masses
to accumulate foreign debris through mechanical ac-
cretion. An important observation, in regard to the
content of the armor, is that “frail gastropod shells
were occasionally as perfectly preserved as though they
had been packed in cotton” (Bell, 1940, p. 18); this
fact may in part explain the undamaged condition of
the ostracodes and conodonts found in the mixed coal
balls.

A paper by Kindle (1937) contains descriptions of
an even more appropriate modern analog of the mixed
coal balls. Kindle observed that after the Atlantic
coast hurricane of mid-September 1936 “boulderlike
masses of tenaceous lagoon clay bound firmly together
by salt grass roots were seen widely scattered over the
flat surface of a lagoon island” (Kindle, 1937, p. 433)
at an inlet a few miles southwest of Atlantic City, N.J.
In regard to marine shells in many of the boulders, he
stated that “theso recent fossils do not represent a
veneer of shells attached to the surface by rolling about.
They have clearly been entombed in the sediments as
they were laid down near the shore of the inlet or bay.
From the original bed these mud boulders have ap-
parently been separated by undercutting of currents
in lagoon channels and the lifting power of waves.”

Perhaps the best documented study of effects of a
severe storm on a low-lying coast is that made following
hurricane “Audrey,” which struck southwestern I Louisi-
ana on June 27, 1957 (Morgan, Nichols, and Wright,
1958) . Two large arcuate masses of marine mud, each

O -61 -»

more than 2 miles long and 1,000 feet wide, were driven
between 1,100 and 1,250 feet inland. Tidal salt water
extended more than 30 miles inland, and some areas
were still inundated 3 weeks after the storm struck.

An older analog was described in some detail by
Croneis and Grubbs (1939). They reported subspheri-
cal calcareous nodules containing assemblages of silici-
lied marine animal fossils in dolomitic beds of Silurian
age near Chicago, Illinois; they interpreted these nod-
ules as mechanical accretionary structures formed by
the action of storm waves on clastic calcareous muds in
relatively shallow sea waters.

Although other descriptions of clastic balls have been
published, the foregoing selected examples illustrate
the points of emphasis in our interpretation of mixed
coal balls. Under certain circumstances, wave or cur-
rent action does dislodge chunks of plastic sediments,
wears and deforms them, and transports them to new
environments; it also forms similarly shaped masses
through mechanical accretion and transportation. In
either instance the remains of organisms may be incor-
porated within the sediment. It is the shaped chunks
of plastic mud that we compare with the Berryville
cores.

HOMOGENEOUS-MIXED AND FAUNAL COAL BALLS

The homogeneous-mixed coal balls from Kansas,
Oklahoma, and Iowa are of less obvious origin than the
Berryville, 111., specimens because of their less clearly
delineated structural features. Nevertheless, we
believe that they can be attributed to a series of events
and a physical environment similar to that suggested
above. Most of the Kansas homogeneous-mixed coal
balls, and perhaps all of those from Oklahoma, may
best be considered analogous to the core of a Berryville,
111., specimen. They may represent transported marine
mud lumps whose chief difference from the Berryville
cores is that they usually are directly enclosed by coal
rather than by a layer of petrified plant material. The
presence of varied marine faunas within the coal is,
of course, the primary evidence of transportation, but
the texture of some mixed coal balls is also worth
consideration.

The swirled texture of some of the homogeneous-
mixed coal balls may be regarded as evidence of pre-
lithification rolling of fossiliferous mud lumps. The
swirls are usually irregularly ovoid ; they are sometimes
vaguely market! and are often accompanied by thin
stringers of decomposed plant material which extend
for some distance into a nodule. More important, the
swirls are primarily effects of animal shell fragments
oriented with their flatter surfaces more or less parallel
along curved lines (pi. 27, fig. 4). This alinement may

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214

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

be the result of adhesion of shell fragments to the sur-
face of a rolling mud lump, or may be secondary ori-
entation by pressure on the enclosing matrix. Pres-
ence in a few mixed coal balls of two or more distinct
sets of swirl markings may indicate adhesion of several
originally separate mud lumps that- were indurated,
after deposition in the swamp, by additional calcium
carbonate and pyrite.

Still other homogeneous-mixed coal balls may
actually be more closely comparable to the Berryville
cores, although not texturally so clearly delineated.
Some of these contain pockets of marine fossils, which
may lie either well within the coal ball or only along its
periphery and which merge vaguely with areas contain-
ing only plant material. These pockets suggest an
origin similar to that of the Berryville cores: that is,
marine mud lumps deposited on the surface of the peat
and ultimately incorporated along with some of the
peat into the same coal balls. Before lithification, how-
ever, partial solution of the calcareous mud lumps may
have occurred and permitted some intermingling of the
marine animals and the surrounding peat.

Several processes are considered possible for forma-
tion of the rare specimens, such as the one from Oska-
loosa, Iowa, in which an ostensibly normal coal ball
contains a sparse mnrine fauna with no physical evi-
dence of enclosing marine sediments. A small lump
of transported mud may have been dissolved chemically
or dispersed by gentle current action after deposition in
the coal swamp; such action would have released the en-
closed animal remains, which sank into the spongy peat
mass and eventually became part of an otherwise normal
coni ball, formed through concretionary growth. An-
other possible explanation is that disintegration of
mud lumps during transportation could have released
the contained fossils ns the waves passed over the coal
swamp; again exotic animal remains would have been
incorporated in coal balls. A third possibility is that
the shells were introduced ns clastic particles in a mud
slurry. Perhaps some of the animals thus introduced
into the coal swamp were actually living at the time
of inundation, and were swept along as part of the
foreign debris. However, the foraminiferal-incrusted
inner surfaces of many of the shells in the Kansas and
Illinois coal balls indicate that the animals were dead
before deposition in the coal swamp.

Striking evidence of twofold transportation of plant
material is found in the Kansas mixed coal balls.
Some residues contain abundant tests of serpulopsid
foraminifers, a generalized and simple, irregularly
tubular adherent type. These tests are commonly ad-
herent on the associated invertebrate shells (pi. 34, fig.
46) but are also found on plant debris (pi. 33, figs.

25-30). They are most common on the large mega-
spore species Triletes cf. T. superbus, where they occur
on both the outer and inner surfaces of the spore coat
(pi. 33, figs. 27-30). That these occurrences are not
accidental juxtapositions is shown by the exact con-
formity of the foraminiferal tests with the spherical
contours of the spore surfaces. The foraminiferal en-
crustation of the terrestrial plant material occurred
in a marine habitat, and there seems no alternative to
attributing this association to twofold transportation
of the encrusted plant fragments.

The above concept actually strengthens rather than
weakens the logic of our interpretation, because trans-
portation of land-plant material from near-shore en-
vironments to the ojien sea and its subsequent deposi-
tion on the sea bottom among the remains of marine
organisms is a well-known phenomenon. White
(1911) summarized from the records of the Blake , the
Challenger , and the Albatross several accounts of land-
plant debris having been dredged from the sea bottom
at depths of as much as 2,150 fathoms.

The Monmouth, Kans., occurrence of mixed and
faunal coal balls in the Bevier coal is the most difficult
phase of this overall problem to interpret, and one
which warrants further and more detailed investiga-
tion. The large amount of xenoclastie marine animal
debris incorporated in the coal there is obviously a re-
flection of proximity of coal swamp and sea waters.
The plant accumulations may even have lain at the
actual strand line at the time of deposition, and have
thus allowed more abundant introduction of marine
muds into the swamp. Possibly the peat deposit was
unusually spongy with large and abundant interstices
that became filled with mud lumps before the weight
of overburden could compress the peat and cause col-
lapse of the interstices. This process could explain
t he distribution of the faunal coal balls throughout
the thickness of the seam. An alternative hypothesis
that the coal itself is an allochthonous marine deposit
is disproved by the presence of a well-developed stig-
marian underclay. There is no obvious explanation of
the scarcity of recognizable plant material in the coal
balls, but it may be due to the extreme pyritizafion,
which is several times higher in the monmouth coal
balls than in those from other localities and which may
have obliterated plant structures that were originally
present.

Whatever the origin of the faunal coal balls, it is
evident that they were brought about by a very local-
ized set of circumstances, for their occurrence in. the
Bevier coal has not been sufficiently widespread to at-
tract the attention of previous workers. Although 14
mining localities were visited during his investigations,

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

Hambleton (1953, p. 56) remarked that coal balls occur
“only in the Mineral coal” and, furthermore, that nod-
ular pyrite is rare in the Bevier coal.

ALTERNATIVE INTERPRETATIONS

The difficulty of arriving at an interpretation of
these mixed coal balls that might lie exacted to meet
with a consensus of approval has l>een emphasized to
us by discussion with severul colleagues. Mixed coal
balls have lx>cn suggested to us to represent filled
animal burrows, erratic limestone boulders, or cavities
filled by normal sedimentary processes. Although
none of these ]>ossibilities appeals to us, it seems fitting
to discuss each briefly and to present the contradic-
tory evidence.

The animal-burrow hypothesis was suggested chiefly
by the appearance of one of the heterogeneous-mixed
specimens from Berryville, 111. This specimen, shown
in plate 31, figure 1, contains the most symmetrical
marine core found, the core itself being some 1G inches
long and 2V6 inches in diameter. Its remarkably
cylindroid shape is rather atypical of the Berryville
cores, but at the same time is somewhat suggestive
of an animal burrow. Evidence against such an in-
terpretation follows:

1. The orientation of this particular core is parallel with

the primary axis of the containing coal ball and,
accordingly, parallel with the bedding of the coal
itself. Assuming that such a horizontal burrow
was made at a time when marine muds and animal
debris were available as a filling substance — after
marine encroachment and deposition on the coal
swamp surface of marine sediments — complete
filling of the burrow would have necessitated hori-
zontal infiltration through a relatively narrow
pathway. Moreover, if the overlying sediments
were the source of the burrow fillings, the cores and
the limestone presumably should have the same
texture and fossils. However, the crinoidal frag-
ments in the cores, being relatively well sorted and
smaller than those in the overlying limestone, im-
part a finer texture to the cores. Large spores,
which are fairly abundant in the cores, are ap-
parently nbsent from the overlying limestone.

2. In most of the heterogeneous-mixed coal balls it is

impossible to demonstrate sufficient uniformity or
symmetry to suggest the origin of the cores as
filled burrows. Aside from a few Berryville cores
similar to that which suggested filled burrows as a
possible interpretation, most of the marine in-
clusions from that locality are irregularly shaped.
Furthermore, animal burrows can scarcely account
for the lenticular or irregular shapes of the homo-

215

geneous-mixed coal balls from Kansas, or for the
unusually large size of some.

The interpretation that mixed coal balls represent
indurated erratic boulders analogous to the boulders
descril>ed by Dix (1942) and Price (1932) from Welsh
and American coal beds seems unlikely. If the mixed
coal balls represent indurated boulders of fossiliferous
limestone that were swept into the coal swamps, it is
difficult to explain the lenticular shapes of some speci-
mens. Assuming that the specimens were indurated
boulders at the time of introduction into the coal swamp,
they would have been resistant to deformation of shape
by compaction, and thus must have been lenticular in
shape at the time of their deposition, in which case some
other physical agency must have shaped them. It
seems improbable that t hey were either tom loose from
their source beds as small lenses, or that they were worn
into such regular shapes through hydraulic erosion
between the times of their derivation and deposition.

Further, in the Berryville mixed coal balls, the con-
tacts between the cores and surrounding normal matrix
commonly are sharply definable, but here and there are
small areas where the contact is poorly developed and
where plant material continuous with that of the normal
matrix extends into the core for some distance. The
material may be either woody axes that have clearly
punctured the core matrix or may be partially decom-
posed, more or less finely comminuted, plant hash that
grades almost imperceptibly into the core. These small
areas suggest that at the time of its deposition in the coal
swamp, part of the core was sufficiently plastic to allow
for some mixture of its substance with the surrounding
peat.

The view has been expressed that the mixed and
faunal coal balls may be the result of normal sedimenta-
tion — that is, that the fossil animals may represent
part of the first fauna that entered the drowned coal
swamp. Although this view deserves serious consider-
ation, again we regard it as untenable for several
reasons :

1. The fossil associations described here and their
ecological implications are not normal. Although
Pennsylvanian stratigraphy and paleontology,
especially of the economically important coal beds,
have been studied intensively for over 100 years,
to the best of our knowledge no one has previously
reported marine invertebrates within the coal
seams, except as contained in shale partings. In
summarizing contemporary knowledge of Ameri-
can Pennsylvanian sedimentation, Weller (1957,
p. 348) noted that “animal fossils, however, are
exceedingly rare in coal seams, and those which

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216

SHORTER CONTRIBUTION'S TO GENERAL GEOLOGY

do occur almost invariably are preserved in cannel
or canneloid layers.”

2. Except for channels, “washouts,” and rare sedi-

mentary dikes, the upper surface of the coal seam
is most commonly a flat surface. Had the upper
surface of the coal-forming peat been notably ir-
regular, plugs, sheets, and other irregular bodies
of marine sediment should be common in coal
seams. If the faunal and mixed coal balls were
fillings of surface irregularities through normal
sedimentation, they would likely be continuous
with the overlying sediments; instead they are dis-
crete bodies buried within the coal and have a
vertical distribution throughout the thickness of
the seam.

3. The coal on the upper surface of the animal-contain-

ing coal balls indicates that peat deposition
continued after deposition of the marine inclu-
sions. A permanent, marine inundation that
would have permitted a marine biota to flourish
on the flooded peat surface would have killed the
vegetation and stopped peat deposition.

4. In the West Mineral area of Kansas the fauna of the

shale above the Fleming coal (Williams, 1937, p.
105) has a different aspect from that of the mixed
coal ball fauna, being locally a coquinoid mass of
productoid brachiopods.

5. The swirled texture of some of the homogeneous-

mixed coal balls, as well as the fragmentary nature
of the larger fossils, suggests transportation.

CONCLUSIONS

Studies of animal-containing coal balls suggest four
conclusions, enumerated below. Some of these are
long-established concepts in coal sedimentology, but
they are incorporated here to complete the picture of
depositional environments we are attempting to recon-
struct, Whether these interpretations meet with
general acceptance or not, it is hoped that this report
will direct increased attention to the still prcplexing
problems of the physical and chemical genesis of normal
coal balls.

1. Some coal swamps were close to seashores and lay

at or very near sea level, separated from the sea
by a bar or barrier (White and Thiessen, 1913,
p. 54) . The coal beds containing mixed or faunal
coal balls represent seaward parts of the swamps.
The barrier between the sea and the swamp was
low enough to be transgressed by unusual wave
action.

2. Under episodically unusual circumstances the coal

swamps were briefly invaded by sea waters and
were contaminated with minor amounts of clastic

marine material. Such invasions, although proba-
bly of very localized nature, occurred repeatedly
in time and space, as shown by the geographic
and stratigraphic distributions of mixed coal balls.
They also were so brief that peat accumulation
was not noticeably interrupted. The presence of
mixed coal balls within the seams constitutes the
only physical evidence for the marine invasions.

3. The American material described here introduces

the probability that not all coal balls were formed
under identical circumstances. Stopes and Wat-
son (1908) suggested that coal balls developed by
concretionary growth after marine invasion and
cessation of peat deposition, the dissolved carbon-
ates in the sea water percolating downward
through the uncompressed peat and forming the
matrix of coal balls. Since Stopes and Watson
found no evidence of transitory marine inunda-
tions, their conclusions are sound insofar as their
data are concerned.

On the other hand, transitory marine ingressions
could have had various effects on the swamp en-
vironment, which in turn may have stimulated
concretionary growth of normal coal balls before
final marine inundation. Waves and currents
powerful enough to transport chunks of marine
mud into the coal swamp would also have carried
significant amounts of the mud in suspension, as
well as carbonates in solution. Assuming that this
mud was calcareous, it may have provided chem-
ical material for concretionary calcification of some
normal coal balls. The mechanism for reprecip-
itation of the carbonates remains speculatory at.
best, but subtle localized variations in pH may
explain it as well as the sporadic occurrence of
coal balls.

4. Coal balls may be concretionary, clastic, or both.

Exclusively plant-containing, concretionary, and
most probably autochthonous (normal) coal balls
preponderate, but others contain marine animal
remains and are interpreted as clastic alloch-
thonous material (homogeneous-mixed and faunal
coal balls) ; still others (heteregeneous-mixed coal
balls) combine both types of contents and modes
of origin.

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL HALLS

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DETAILS OF SAMPLES AND INSOLUBLE RESIDUES

0SKAL00SA, IOWA

One coal ball (sample K-13) from the Patik mine was avail-
able. Parts of this specimen are Illustrated on plate 31. tlgurcs
2 and 4. It Is one of the more slgnlllcant specimens studied iu
this research. Casual Inspection of Its sawn surfaces suggests
an apparently normal coal ball with no conspicuous I tedding or
textural features. However, close examination reveals a few
small gastvopod shells scattered here and there. The pre-
dominantly cordallcau plant contents are very well preserved,
even though pyrite is conspicuous in the matrix. The pyrlte
is partly oxidized, so tliut its dull luster renders it
Inconspicuous.

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218

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Residue.* of this sample are high In pyrtte content, but
abundant organic remains, mainly plant material with many
coalifled wood fragments and well-preserved pieces of cuticle of
several types, were also recovered. The sample also contains
the most diverse large-spore assemblage recovered In this
study. Tills Includes Trilctes cf. T. supcrbus, T. triangulatu*
(pi. 33. figs. 21. 22). T. auritus var. grandis, Spencerisporites
sp.. Monolctes ovatux, and Cgstosporitcs sp. Sample E-13 com-
bines the widespread Spencerisporites type of spore with forms
of Triletes that seem to characterize samples from other dis-
tinct areas but which rarely appear together In the same
sample.

The fauna consists only of a few conodonts (pi. 34. flg. 45),
pyrltlzed ostracodes. and pyritlzed gastropods, which establish
the presence of a marine element In this otherwise normal-
appearing coal ball.

McALESTER, OTTLA.

Several mixed coal balls from McAlester, Okla., were studied.
In a few, the animal remains appeared to be locnlly concentrated
In hazily defined bluish-gray parts of the matrix, which were
lighter In color than the remainder and showed faint swlrlllke
markings on sawn surfaces. Otherwise, these coal balls showed
no distinctive textural features, and in most there was no
obvious segregation of the animal remains.

Animal assemblages from this locality are mostly dominated
by well-preserved pyrltlzed ostracodes. Peleeypods and gas-
tropods are fairly common : conodonts, fish remains, and other
animal groups ore only sparsely represented. The following
samples were dissolved :

B-ll . — Organic contents of the residue are largely of plant
origin. Most of the plant fragments are small, and their
parallel ribbing and stomata arranged In rows parallel to the
ribs Indicates they are coalifled cordaitean leaf fragments.
Fuslnlzed wood fragments and cuticular remnants are also
common, but very few spores were found. Most of the spore
material consists of incomplete but uncompressed fragments
of the Trilctes auritus tyi>e ; one small lagenlculate specimen
of Trilctes (cf. T. rugosus ) was also found.

With the exception of conodonts and fish remains, the animal
fossils are all preserved as pyritlc replacements. Poorly pre-
served Ostracodes are most common, small peleeypods are rela-
tively abundant worm tubes (pi. 34, flg. 46), gastropods, and
fish fragments are rare, and one bryozoan was found.

E-22 . — This coal ball was similar to E-ll, although slightly
less pyrltlzed. Almost the same plant material Is present in the
residue; several specimens of a lagenlculate species of Triletes
(cf. T. rugosus) were recovered (pi. 33, figs. 18, 19).

Among the animal remains, ostracodes are again the dominant
element, with gastropods (pi. 34, flg. 31) and pelecyiskls (pi. 34,
flg. 27) also common. A few bryozoans, conodonts (pi. 34. figs.
42, 43), scolecodonts (pi. 34, flg. 35), inarticulate brachiopods
(pi. 34, figs. 17, 18). and flsh fragments (pi. 34, figs, 52-57) were
found, along with attached and free-living foraminlfers. Some
coprolites also occur (pi. 34, figs, 33, 34), as do worm tubes
(pi. 34. figs. 38,46).

ESO . — This small normal coal ball api>eared to contain mod-
erately well preserved plant material, but the residue yielded
only a few spores, cuticles, and pyrtte-fllled woody fragments.
The spores Include a few siieclmens of Trilctes cf. T. rugosus ,
two questionable fragments of T. auritus, and one specimen of
Monolctes ovatus.

No animal remains are present In the residue.

ESI . — This Is a large Irregularly shaped homogeneous-mixed
coal ball, a foot long and nearly as broad. Several stringers of
coal extend Inward 1 to 2 inches from the periphery of the coal
ball, whose content appears on sawn surfaces, to be poorly pre-
served plant material. Betiding was not detected In the
specimen.

Animal remains are Inconspicuous on sawn surfaces and are
not concentrated at any spot. The fauna in the residue is
primarily moluskan, with several genera of peleeypods and
gastropods, the former being the more abundant (pi. 34. figs.
22, 28). One species of cephatopod also occurs (pi. 34. flg. 29).
The remainder of the fauna consists of a few flsh fragments,
inarticulate brachiopods, foraminlfers (pi. 34, flgs. 3. 8), some
ostracodes, and a relatively large number of worm tubes.

Plant material is represented by many coalifled wood frag-
ments and a few cuticular scraps and sjiores. The latter con-
sist of approximately equal numbers of Triletes cf. T. rugosus
and T. auritus var. grandis. One specimen of Cgstosporiles
rarius was also found.

E-16 . — Associated with the Secor coal, and presumably above
It, Is a fosslllferous limestone. A sample was dissolved to ascer-
tain whether any relation exists between the fauna of the mixed
coal balls and that of the limestone caprock.

Animal remains In this sample are all pyrltlzed and too
poorly preserved for generic or specific Identification. The
fauua shows less diversity than those of the associated mixed
cool balls. It contains a few specimens of three genera of
peleeypods, one genus of gastropods, some Inarticulate brachlo-
pod fragments, foraminlfers. and flsh parts.

Plant material consists only of small fragments of fuslnlzed
wood and a few resin rodlets.

SOUTHEASTERN KANSAS

WEST MINERAL — PITTSBURGH AND MIDWAY COAL CO.

PITS

A large number of homogeneous-mixed coal balls from West
Mineral, Kans., were examined. Some show rather well de-
fined swirled textures, particularly the few that contain larger
brachiopods. A few others show local concentrations of ani-
mals surrounded by fairly pure plant material.

The West Mineral specimens contain more pyrite and other
Insolubles thun those from any other locality, with the exception
of the Apex-Compton mine near Monmouth. (See table 2.)
However, a few of the West Mineral coal balls approach the
latter in degree of pyritlzation.

Biologically, the West Mineral materia) Is the richest ex-
amined thus far, both for variety and size of fossils. It con-
tains Marginlfcro and small s|ieclmen.s of Dcrbyia. Animal
remains ns large as these have not been found In mixed coal
balls from any of the other localities.

Aside from the large bracliio|>ods, most of the faunal con-
tents are small unbroken Individuals, either mature or pre-
served In younger growth stages. A few small (2 mm and less
In diameter) brachiopods and peleeypods were found, with
ornamentation and delicate spines undamaged.

E-9 . — This large coal ball lacks any distinctive textural fea-
tures and contains relatively few nnimals, scattered throughout
the matrix. Although a few larger brachiopods and 2 cepha-
IojmkIs are evident on the sawn and broken surfaces, the acid
residues contain a sparse fauna that consists only of 6 speci-
mens of gastropods, one pelecypod. and several conodonts and
poorly preserved ostracodes.

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

219

Recovery of plant material was poor, but a fairly large
number of uncompressed spores are present In the residues.
These contain Spcnccrisporites sp., Triletes cf. T. superbus, and
T. triangulatus.

B-10 . — This is a small, heavily pyritized coal ball that appears
normal except for a few gastropods evident on cut surfaces.
The faunal content of acid residues consisted only of four
small gastropods. The plant material contains many fuslnlzed
wood silvers, a few resin rodlets, and some cutlcular material.
Numerous spores were recovered, chiefly large specimens that
appear to represent spores of Triletes cf. T. superbus in which
the large equatorial frill has been accidentally separated from
the spore body ; one specimen of Bpencerisporitcs sp. was also
found.

B-12 . — Many animal fragments, including larger brachlopods,
are visible on sawn surfaces of this specimen, and are scattered
throughout the matrix. Although few of these were recovered
in the acid residues, they embrace a variety of zoological
groups. Several larger brachlopods and fragments of inartic-
ulate brachlopods, a few pelecypods and gastropods, fish scales
and teeth, oetracodes and adherent foraminiferal tests make
up the fauna.

A varied spore population dominates the plant material.
Most conspicuous are Triletes cf. T. superbus and Bpcnccris-
porites sp. ; T. triangulatus, Monoletes ovatus, and T. auritus
constitute a slightly less conspicuous fraction of the spore
assemblage.

E-18. — This specimen was selected as a representative nor-
mal coal ball. Careful inspection of its sawn surfaces showed
no animal fossils, and their absence was corroborated by the
acid residue.

Abundant plant cuticles and spores were recovered. Tri-
letes cf. T. superbus, so conspicuous In mixed coal ball speci-
mens, is lacking In tills sample. However, T. triangulatus,
Spcnccrisporites sp.. and Slonolctes ovatus are present, and
establish a common element with the mixed coal balls.

B-23.— This large nnlayered coal ball contained numerous
animals, homogeneously scattered among the plant remains
throughout the matrix. Faunally, It proved to be one of our
richest specimens. Acid residues yielded numerous pelecypods,
gastropods, and larger brachlopods (pi. 34, flgs. 19, 20), two
specimens of cephalopoda, rare oetracodes, llsh remains, cono-
donts, one scoleeodont, abundant worm castings, a spongelike
object, and many adherent forminiferal tests of the Serpulopsis
type. The latter are also attached to associated fossils, both
plant (pi. 33, flgs. 25-30) and animal.

Plant remains in the residue contain abundnnt fuslnlzed
wood fragments, cutlcular material, one eoallfled lycopodiaceous
branch tip with Intact leaves (pi. 33, fig. 32), Intact masses of
small spores, resin rodlets, and numerous large uncompressed
spores. The latter are dominated by Triletes cf. T. superbus.
which, with its ornate equatorial frill and trilete appendages
presents a striking appearance in its fully distended, natural
shape (pi. 33, flgs. 5-7). Some specimens of this species have
pyritic fillings (pi. 33, flg. 9), while the empty Interiors of still
others indicate the calcltic nature of their former fillings.
Many specimens of this species were found with Serpulopsis
tests adherent, both internally on broken fragments (pi. 33,
flg. 28) and externally on intact specimens (pi. 33, flgs 27
29. 30).

Other spores present in this sample are T. triangulatus,
Spcnccrisporites sp., and Monoletes ovatus.

E-2.J. — This small coal ball yielded few animal remains with
the exception of abundant foraminiferal tests of the Serpulopsis
tyjie. The few pelecypods recovered are diversified generlcally.
A few spores of Triletes cf. T. superbus and T. triangulatus
were recovered ; these represent the total of recognizable plant
material.

E-l\. ( Limestone overlying Mineral Coal). — Residues of
this sample contain. In addition to pyrlte. an abundance of
small flakes of silty material, which is not present in significant
amounts in any of the coal ball specimens.

Recovery of fossils was low. The animals consist mostly of
ostracodes and broken undetermined brachiopod spines. Plant
material, also scarce, consists of rare cuticle fragments, slivers
of fuslnlzed wood, compressed and poorly preserved Triletes-
type megaspores, and two uncompressed specimens of
Spcnccrisporites sp. The latter provide the single common
botanical element with the coal ball residues.

MONMOUTH — APBX-COMPTON COAL. CO. PITS

The area of the Bevler coal seam now being mined by the
Apex-Compton Co. is unusual in that its abundant nodular
impurities, which we consider to be coal balls, are extremely
p.vrltlc and composed almost exclusively of animal fragments.
In the many coal ball samples examined, plant remains are
nearly or completely absent, while the closest approaches to
normal coal ball samples yielded only fragments of fuslnlzed
wood.

Some of the mixed coal balls show homogeneous texture and
are heavily pyritized throughout. In others, however, the ma-
trix is differentiated into a fairly distinct central nucleus of
nearly pure pyrlte in which all fossils have been completely
obliterated, surrounded by areas of less complete pyrltlzatlon
in which fossils may be recognized. A few specimens contain
roughly concentric zones of varying concentrations of pyrlte.

Four samples were dissolved, including one that seemed to be
a normal but poor quality coal ball.

B-7. — The specimen is a slightly flattened nodule with adher-
ent coal chips on all surfaces and streaks of coal incorporated
within the matrix. It contains n clearly defined, nearly central
area of almost solid pyrlte thnt is surrounded by a less heavily
pyritized zone In which animal fossils are abundant. A few
calcareous crinoid columnals are apparent on sawn surfaces,
but most of the animal remains are pyritized brachlopods and
gastropods.

The residue is estimated to contain 90 to 95 percent pyrlte,
most of which consists of finely comminuted animal shell frag-
ments thnt apparently originated from productold brachlopods
and lnrge bellerophontid gastropods; the pyrlte Is relatively
lustrous and unoxidized. The residue also produced a number
of complete small generlcally diversified gastropods (pi. 34,
flgs. 25, 2(1), some poorly preserved ostracodes, foraminiferal
tests, conodonts, and fish remains.

Except for very rare and small fuslnlzed wood particles,
plant remains are absent from this sample.

E-B. — This specimen is similar to E-7, but less pyritized.
The residue consists mostly of small fragments of Invertebrate
shells. The determinable faunnl content is similar to that of
E-7, except for the absence of foraminiferal remains.

No plant remains were observed in the residue.

E-20. — This specimen has adherent coal on all surfaces and
coaly inclusions within the matrix. Sawn surfaces contain a
definite, almost centrally located mass containing well-pre-

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220

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

served barltle fossils. This area is surrounded by a zone of
heavy pyritization in which the animal remains are also
pyrltlzed, and there is a clear contact between the two zones.
Local areas of the outer zone are so heavily pyritlzed that the
fossils are practically obliterated.

A part of the Inner zone was dissolved, and it produced a small
amount of residue. The faunal content of the residue contained
abundant barltle gastropods (pi. 34, figs. 23, 30), rure baritic
pelecypod fragments, a few conodonts, and fish remains.

The plant remains consisted only of small fuslnlzed wood
particles and a sparse spore assemblage, which includes ilono-
tetff* ovatua and Triletea cf. T. auritua.

E-21 . — This is a small ellipsoidal, apparently normal coal
ball, with only poorly preserved cordaltean wood fragments
apparent on sawn surfaces. Acid solution produced only
woody splinters, highly impregnated with pyrite. No spores
or animal remains were noted.

FRANKLIN — MACKIE-CLBM ENTS FUEL CO. MINE NO. 98

Normal coal balls from this locality cannot be distinguished
from those of the Pittsburgh and Midway mine on the basis of
plant contents or overall appearances. This fact would seem
to lend weight to local miners’ opinions that the same coal
seam is being mined at the two sites. ( See p. 201. )

The mixed coal ball specimens are variable in pyrite content,
and the pyrite may be more concentrated In one part of the
nodule than another. None, however, are as heavily pyrltlzed
as the Monmouth specimens.

The fauna included in the mixed specimens is fairly varied,
but apparently dominated by the brachiopod Sleaolobua, In-
variably replaced by pyrite. Calcareous crinold columnals
are abundant on sawn surfaces; they occur even in the most
heavily pryitlzed parts of the nodules; these, of course, are
lost in the acid treatment. Ostracodes, ehonetid brachiopod
spines, and worm castings are also common, and there are a
few other faunal elements, as noted below.

Plant material la very rare in residues of mixed specimens
from this locality.

E-l . — The sample does not appear to be heavily pyrltlzed,
nor does It show outstanding textural fentures. The residue
Is approximately 00 percent pyrite. but this includes no large
masses such ns characterize residues of the Monmouth speci-
mens ; the pyrite is relatively lustrous.

The larger animal fragments are apparently of Meaolobua
(pi. 34, flg. 21) and larger productoid origin, while the finer
screen sizes of the residue consist of jierhaps 50 percent brachi-
opod spine fragments. In addition to the brachlopods, several
crinold columnals, foramlnlferal tests, rare ostracodes (pi. 34,
figs. 47. 51), conodonts, and fish fragments were found.

Plant material consists mostly of small fragments of fusl-
ntzed wood; cuticular material is very rare, and spores were
not noted.

B-2 . — This sample has a swirled texture and Is more pyri-
tlzed than E-l ; recovery of fossils was poor. Pyritization is
especially localized in one eccentrically located area. The
pyrite constitutes approximately 05 percent of the residue and
lacks luster. The most abundant animal fossils recovered
were fragments of Sleaolobua. In addition, a few crinold
columnals, several gastropods, poorly preserved ostracodes,
conodonts, and fish remains were noted.

Plant material Is rare: it consists largely of small fragments

of fuslnlzed wood and a few reesin rodleta. No spores or cutic-
ular material were found.

B-l 7 . — This is a normal coal ball, with vague horizontal lay-
ering. Parts of the specimen contain large pieces of cordaltean
wood, but many well-perse rved smaller plant structures are
evident on sawn surfaces (principally Cordaiearpua, Stigmaria,
and Scolecoptcria). However, surprisingly few identifiable
fragments survived acid solution. The residue of this sample,
which contains very little pyrite, yielded only fusinlzed wood
particles, cuticular fragments, and a few spores, which
contain Spenceriaporite a sp., Slonoletea ovatua, and one tetrad
of Triletea triangulatua.

No animal remains were found in this sample.

BERRYVILLE, ILL

Mixed coal balls from this locality are unique in several re-
spects, the most striking of these being the clearly defined
cores of marine sediment incorporated within the otherwise
normal type of coal ball matrix (pL 30, flg. 1-3; pi. 31, flg. 1).
They are further unique in their high proportion of acid-
soluble carbonates. None of the Berryville coal ball samples
contained as much as 6 percent insoluble matter, whereas sam-
ples from other localities contained from 6.1 to 36 percent.

From the zoological standpoint, Berryville material is dis-
tinct in that its fauna is dominated by pyritlzed bryozoans, a
group that is nearly absent from all other samples. Further-
more it contains pyritlzed trilobite fragments, which are
unique in coal balls from this locality. Siliceous foraminiferal
testa and crinold columnals are also much more conspicuous
here than elsewhere. The residues also contain coalifled wood,
cuticles, and many well-preserved spores.

The marine cores of mixed coal balls also seem to be low
in pyrite content, and their sawn surfaces show many calcified
crinold remains. The residues contain 50 to 60 percent pyrite,
but this is either in the form of a fine powder or animal re-
placements; It rarely appears in large amorphous masses like
thoee contained in residues from other localities.

In view of the unusual nature of Berryville coal balls, a
large suite of samples was dissolved. This suite includes: (a)
core material from which all normal matrix had been carefully
trimmed; (b) samples of normal matrix surrounding the core;
(c) samples of a normal coal ball; (d) samples of limestone in-
corporated within the coal seam; and (e) samples of the lime-
stone overburden.

B-3 . — This specimen was taken from a long cylindroidal
core containing several conspicuous calelte-fllled shrinkage*?)
cracks. Its cut surface showed many crinoid columnals and
tubular foraminiferal tests. The residue is smull (2.9 percent
of the total weight), but contains a varied assemblage. Ani-
mals include conodonts, pelecypods, gastropods, rare brachio-
pods, fish fragments, common foraminiferal tests, a few trilo-
bites, and abundnnt bryozoans.

Abundant plant material Is present, including fusinlzed wood
and cuticular fragments, in addition to a varied spore assem-
blage. Spores Include Triletea auritua var. grandia, T. trial v-
gulatua, T. glabratua, Spenccriapori tea sp., Monoletea ovatua
(the most abundant form— see pi. 33, figs. 1, 2), and a few
specimens of Paraaporitea ct. P. maccabci (pi. 33, figs. 23. 24).
Small trilete spores are abundant in the finest residues, but
there were not identified.

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OCCURRENCE AND SIGNIFICANCE OF MARINE ANIMAL REMAINS IN AMERICAN COAL BALLS

221

R-4 . — This sample resembles E-3. but Its Insoluble residue Is
smaller and contains less pyrite.

The fauna Is nearly the same as that of E-3. except that
foramlniferal tests are more conspicuous here. A plant as-
semblage similar to E-3 and differing only In the absence from
E— I of the Paratporitet is also present.

B-19 . — This la a normal coal ball with distinct layering of
Its abundant and well-preserved plant debris evident on sawn
surfaces. It was selected for solution in order to determine
(a) whether animal fossils are actually absent, as suggested
by Inspection of sawn surfaces, and (b) what comparisons could
be made between Its plant content and that of the marine
cores.

I.ittle residue was obtained (4.6 percent), and this contains
almost no pyrtte. The residue, all of plant origin, has the
appearance of a chaffy light- to dark-brown mass of more or
less finely divided fragments of cuticles and wood, complete
spores, and various other reproductive parts. No animal re-
mains were found. Spores are rare : only a few masses of small
trilete spores, two specimen* of Monoletet ovatut, and one
of Bpenceritporitet sp. were found. Surprisingly enough.
Triletet aurltu t was not found in this sample.

This residue is, however, of unusual interest In that it contains
several uncompressed and otherwise undamaged specimens of a
species of small pterldospermous seeds, and numerous
scolecopterid fern fructifications. The seeds are hollow as a
result of solution of their calcitie fillings, and are represented
by a delicate Inflated membrane that probably Is the inner layer
of the testa (endotesta). Cellular outlines may easily be seen
with a dissecting microscope. Although the seeds cannot be
identified without a knowledge of their Inner structural details,
overall size and shapes suggest affinity with the genus
Coronottoma Neeley, which has been described from Berry-
vilte coal ball material ; at any rate, they are unquestionably
cono8tomalean structures (pi. 33, fig. 31).

The fern fructifications consist of uncompressed s.vnangla that
were apparently preserved after maturity and dehiscence (pi.
33, figs. 33-36). The synangla are evidently referable to
Bcolecopterit minor, and contain four or five sporangia each, the
sporangia being 1 mm. or less in length. Many of the synangla
have their pedicels Intact, and a few specimens of fertile
pecopterid pinnules have been found. Furthermore, one very
delicate circlnate pecopterid frond tip with several pinnules
attached was found.

Although these recoveries have little bearing on the basic
problem under consideration, they demonstrate that studies
of coal ball plant fossils based on the peel technique might
well be supplemented to great advantage by acid solution in
order more accurately to understand the three-dimensional
aspects of the plant fossils Investigated.

E-Z5 . — The residue of this core sample contains one of the
most varied faunas found in this study. Animal remains In-
clude trlloblte fragments, poorly preserved brachlopods, abun-
dant and diversified gastropods (pi. 34, fig. 32), worm tubes and
castings, some pelecypods, conodonts (pi. 34. fig. 36), abundant
ostracode8, foramlniferal tests, bryozoaus (pi. 34, figs. 11, 13-
16), a few fish fragments, and several sponge spicules (pi. 34,
figs. 9, 10).

The usual fuslnlzed wood and cuticular fragments also occur,
along with well-preserved uncompressed spores, the most abun-
dant form being Triletet auritut var. grandit. Monoletet
ovatut, Bpenceritporitet sp., and Triletet glabratut complete
the spore assemblage.

E-26 . — This core was physically similar to E-25. Its fauna
differs from the former only In a larger representation of trl-
loblte remains (pi. 34, figs. 39-41), and the spore assemblage
contains a higher percentage of Triletet glabratut (pi. 34, figs.
3, 4), although T. auritut var. grandit still dominates (pi. 34,
figs. 13-17). Tart of this specimen Is Illustrated on plate 30,
figure 2.

E-27 . — This coal ball contains a very sharp contact delimiting
its cylindroid core, and two samples, one consisting of carefully
trimmed core material and the other of the surrounding normal
matrix, were dissolved to compare the differences In content
between the core and normal matrix surrounding It Part of
this specimen is Illustrated on plate 30, figure 8.

The fauna recovered from the residue of the core is typical of
the Berryvllle material, except that neither oetracodes nor con-
odonts are evident, and a few pyrltlzed crinold columnals were
recovered. Plant material is rare in this sample, the most
conspicuous -elements being a few specimens each of Triletet
auritut var. grandit, T. glabratut, and Bpenceritporitet sp.

The residue of the normal matrix surrounding the core con-
tains no animal remains and little pyrite. It consists only of
plant debris, mostly brown and peaty-appearing. The residue
contains a few scolecopterid fern synangla, well-preserved
cuticles, abundant fuslnlzed wood fragments, and only a few
spores. Identified as Triletet triangulatut, Bpenceritporitet sp.,
and Monoletet ovatut.

E-Z8 . — Two samples of this mixed coal ball were treated as
In E-27. The core residue yielded a varied fauna, unusual only
in the apparent absence of conodonts. Plant debris is scarce;
It consists of the usual cuticles, fuslnlzed wood fragments, and
spores, the latter being represented by Triletet auritut var.
grandit (the dominant form), T. glabratut, and Bpenceritpo-
ritet sp. (pi. 33, figs. 11-14).

Residue of the normal matrix surrounding the core contains
no animal remains and almost no pyrite. Cuticles, fuslnlzed
wood fragments, and spores are abundant, but Bpenceritporitet
sp. Is the only spore type recovered from this residue.

E-29 . — This core sample yielded a varied fauna. Including
trlloblte8, foramlniferal tests (pi. 34 figs. 4. 8), hexactlnelUd
sponge spicules, worm tubes and castings, fish fragments, cono-
donts (pi. 34, fig. 44), articulate and inarticulate brachlopods,
bryozoans, ostracodes (pi. 34, figs. 48-50), and diversified
mollusk*.

The usual type of plant debris Is present In the residue, and
It contains one of the most varied and richest spore assem-
blages found. This assemblage Is dominated by Triletet
auritut var. grandit, but it also contains T. glabratut, T. cf. T.
rugotut, T. triangulatua. Cyttotporitet t'oriiu, Bpenceritporitet
sp„ and Monoletet ovatut.

E-6 . — This sample of the limestone overlying the coal seam
(unit 3 of measured section, p. 198) proved to be nearly pure
carbonate, with Its Insoluble fraction constituting only 0.42
percent of the original weight. Sawn surfaces are similar to
those of the cores, being bloclastic crinoidal limestone. How-
ever, this rock has a significantly coarser and less well sorted
texture, with many of the crinold stems two to three times as
large as those In the cores.

The faunal content of the sample consists only of a few
conodonts, fish remains, tubular foramlniferal tests, and one
specimen each of a scolecodont, a gastropod, and pelecypod.
The gastropod steinkern. though not tested, appeared to be phos-
pbatic. No pyrite Is evident In the residue; plant material la
absent.

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222

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

B-S . — A sample of the limestone Oiling of the presumed chan-
nel cot In the coal seam was more fosslllferous than the over-
lying limestone (E-fl) ; Its residue contains a large proportion
of pyrlte. In texture and faunal content this rock Is very
similar to the cores.

Animal remains recovered from the residue include abundant
bryoioans, relatively few pelecypods, and worm castings,
sparse ostracodes, rare gastropods and brachiopods, and some
trilobltes and conodonts; all but the worm castings and cono-
donts are pyritized.

Plant material Is sparse, with some cuticle and woody mate-
rial and a few well-preserved spores. The latter Include

Trilelet auritu » var. grand i* (the dominant form), T. glabratut,
Rpenccritpnrites sp. and an unknown spore that, except for Its
large size, Is similar to Lycotpora in form.

E-IS . — This Is a sample of the Impure limestone below the
channel as discussed on page 198. This material Is illustrated
In plate 31. figures 3, 5, and 6.

The acid residues contain no animal remains. The plant
debris Is mostly small and unrecognizable flakes of incompletely
eoalifled plant material. However, abundant well-preserved
cutlcular material and uncompressed spores were recovered.
The spores include Trilete* auritu » var. grandit ( the dominant
form), 8pmceri*poritet sp., Triletes glabratut, and one speci-
men of Porotporites ct. P. maccabei.

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INDEX

A Psge

Acanthodll ..... .... 209

Acknowledgments 194—195

Actlnopterygll 209 ; pi. 34

Ammoeertclla 20 ft

inc Into 20S

labyrlntha 208

prodigal!* ... 208

sp 208 : pi. 34

AmpMs.lrc cenlronotue 209 ; pi. 34

»p — 209

Analyses 206, 207

Animal-burrow hypothesis 215

Annelida 208

Apex-Compton Coal Co 194.

199.201.202. 218. 219

Apterrlnella sp 208 : pi. 34

Arabellitet sp 208 ; pi. 34

Atlarlrlla sp...... ............. 208

aurilut grand vs, Triletet 209.

212. 218. 221. 222: Dl. 33
Triletet 209.

218. 219. 220, 221: pi. 31
.1 vtculopecten sp 208

Italrdia 209

garritonentl t 209

oklahomentit .... 209

pompllloldet 209

rhomboldalh ... 209

tfj-ano 209

sp - 209 : pi. 34

Bairdiacypri « sp 209 : pi. 34

Ballast, coal balls used for 199

battlrrl, Gnathodu* 209 ; pi. 34

Bnxtcr. Robert W„ quoted 202

Belgian coal balls 193, 202

Bellerophontld ...... 208

Berryvllte. UL. coal balls 197-199.

206. 207. 208. 209. 220-222 :
pis. 26, 27, 30, 21,

cores 204.

205. 200. 207. 211. 212. 213.
214. 215. 220=222 ; pis. 30, 31
geologic section. .............. 198

ltevler coal 201,

202. 206, 207. 214. 213. 219

Boggy formation ..... ... 197

Bohemian coal balls 200

Horrttu t sp .............. 208 : pi. 34

Botryopteri* 198

Bradydontl 209

Breger. I. A., quoted 211

Bulimorpha sp ...... 209

Calcitornella sp.. ...... 208

Calhoun coal 197. 206. 207

Calvert formation 212

Carrlllna sp__ ............. 200

Cavutgnolhut flexa 209

ccntronoty s, AmphlttUct 209: pi. 34

Cherokee shale 200. 201

Cbonetid 208

Chordata 209

Cladoidachil 209 : pi. 34

Pag «

Coal, Bevler 201,

202. 206. 207. 214. 215. 219

Calhoun 197, 206, 207

Fleming seam.. 200, 201, 206, 207, 216

McAlester 187

Mineral seam 200. 201. 215

Secor 194, 106, 197. 206, 207, 213

Coal balls, definition 195-196

description of samples and In-
soluble residues 2 17-222

Interpretation of animal-contain-
ing 211-216

nucetlar 202

occurrences of animal-contain-
ing 199-202

physical, chemical, and biological

features, faunal 206.

207; pis. 26, 28. 32
heterogeneous-mixed 204-206.

207; pis. 27-29. 31
homogeneous-mixed 197.

203-204. 206. 207 : pis. 27-31
normal 202-203. 206. 207 : pis.

27. 23

. _ _ 208

Compton, 1L \V\, Information provided 201

2in

ConodnntM

209

_ 208 ; pi 32

Corriaicarpus

_ 202.

217,220: pis. 28. 29.31

Cores, tnnrlne

204,

205. 206. 207

, 2U, 215, 220.

221.222: nls. 30. 3L

Cornn*pfro 8p

208

221 : pi. 33

208 ; pi. 34

Cy*to*por4tf-$ rarius 209.

218. 221 : pi. 33

Cv*to"porUe8 sp

209, 218

209

dellcatuta, Oxarkodlna

Derbyia sp 208.

211. 219: pi. 34

19K-19A

Ditomopygr up

209, pi. 34

Donald in a *p

... -209 ; pi. 34

Duosporitca ......

_ r _ 208

Economic use of coni bn 11s.

199

elrgantulun, StreptognatbodiiM 200; pi. 34

Elmore. 1*. L. D., analyst 206

Kndotobu t sp.... ................ . 209

Bndothyra .... 208

t.'ndothyranella powers! 208

sp - 208

English coal balls 193, 194, 202, 206

Kucovhlit sp ... 208 : pi. 34

Fabrlooyprl* sp 209

Fenettella sp ... 208 : pi. 34

Page

Fish remains 209

Flttitpongla sp. ...... .......... 208

Fleming coal seam 200.

201. 206. 207. 216

flexa, Cavutgnathiu 209

Flora, In normal coal balls .... 202

Fossils, distribution 208-209

Fossils, preservation 210-21 1

Frank, Mona, analyat ............ 206

Franklin. Kan*., coal balla 201, 220

Fusultnlda 208 ; pi. 34

Garrett Coal Co 202

garriganen*!*, Batrdta . ............ 209

Geologic section. Berryvllle, 111 198

German coal balls 206

Olrtytplra sp .................. 209

glabratut, Triletet 209.

212, 221,222; pi. 33

Glabroeingulum sp 208

Qlobivalvullno sp 208 ; pi. 34

Olomoeptra sp .................. 208

Olyptoplrura sp....... 209; pi. 34

Qnathodut battler! 209: pi. 34

round]/! 209

sp 209

grand it, Triletet a u tif us 209.

212.218. 221. 222:01.33

ftealdla sp 209

Hexactlnnellld spicule 208

Iltndrodrlla sp. ........ 209 ; pi. 34

Holtinella sp 209 ; pi. 34

Hurricane effects 213

tdtognatbodu s magnlfleut — .... 209 ; pi. 34

Inc fusa, Ammoverlella ... 208

Indurated erratic-boulder hypothesis. 215

Intita, Serpulopt Is........ 208

Interpretation of anlmal-contalnlng

coal balls 211-216

Kansas, southeastern, animal-con-
taining coal balls— 197. 199-202. 218-220

Kegetlltc* dallonen/tlt- — 209

Kellettlna sp... 209

Klrkbya sp ... ..... 209

Knighlina sp ...... 209

Knightlte t l Retltplra) sp...... 208: pi. 34

knoxente , Pseudorthocerai ... 209 : pi. 34

Kousnetxk basin. Russia 206

Krebs group, Boggy formation — ... 197

Laboratory methods.. 207-210

labyrintha, Ammoverlella, ... — .... 208

Lelop terta sp.............. 208

Llnguloid - 208

Lilotlroma .......... 194

Lophophyllld coral 208

Lyeotpora ............. ...... 209

223

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224

INDEX

M page

McAlester, Okla., coni ball* 196-187

200. 207. 21B

McAIeater coal _ 187

McAlentcr shale 197

maecabel, Paratporites 201).

221. 222 ; pi. 83

Mackle-Clemene Mines 201. 220

McLeansboro group. Calhoun coal 197

magnl) Tcus, IcUognothodut 209 : pi. 31

Margini/rra sp . 208. 219: pi. 31

Marine core* 201.

200. 200. 207. 210. 220. 221.
222 ; pis. 30. 31.

Meekotplra sp 200

Mctolobut sp 208. 220 ; pi. 31

ilicrodoma sp 20S

Mineral coal seam 200. 201. 210

minor, Scolecopterie 221 ; pi. 33

minutui, Spathognathodut 209 ; pi. 34

Monmouth. Kans.. coal balls 201-202.

209, 207. 219=220

if onorrratina sp 209

Monolctrt oealut ... 209.

212.218.219. 220. 221 : pi. 33

Mooreocerat sp 209

Mud balls, armored, California-. — 213

Mytllld 208

Xaticoptit sp 209

ReiUonla sp .... 208

Xroprioiodut sp... 200

Normal sedimentation hypothesis 218-210

Xuculana sp ... 208

Nnculold - 208

oklahomentlt, Bairdio 209

Orblculold 208

Oskaloosa. Iowa, animal-containing

coal ball* 197, 217-218

ovntu*, Monoid rt ....... 209.

212,218.219,220,221 : pi. 33

Oeorkodino drliratula ........ 209 ; pi. 34

ap 209

Palcottylu* iPtrudorygoplcura) sp 200

ParaUelodon sp ... 208; pi. 34

Paraparchilet sp 209

Paraeporitet 209. 221. 222 ; pi. 33

maecabel 209, 221. 222 ; pi. 33

Patlk mine. Iowa 198, 217

pouprrala, Tetratoxit 208 ; pi. 34

Page

Pectlnold ..... 208

Pcnnlrdrpora sp ...... 208

Permophorut sp 208 ; pi. 34

Pittsburg and Midway Coal Co 194,

199.200. 201.218. 220

Pleurocantholdl! 209

Pleurotomarlan 208

Polypora sp 208

pompUloldet, Bairdio 209

Porlfera ..... — ... 203

poirrrti, Endothyranella 208

Preservation of the fossils 210-211

Previous work 194

prodlgalit, Ammorertelta 208

Productold 208

Ptaro nittl 198, 202

Pteudorthocerat knoxente 209 : pi. 34

(Pteudotygoplcuro ) sp., Paleottylut . 209

Ramiporatia sp 208

rectangularit, rhurammlna.... 208

References cited 216-217

(Retitpira) sp.. Knightltet 208

Rhabdomrton sp 208

RhipidomeUa sp .... ... 208

Rhombocladia sp 208

rhomboidalit, Bairdio ........ 209

Rhombopora sp ... 208 : pi. 34

Road ballast 199

Roundya ................ ..... 209

nubacoda 209

roundpi, Onathodut 209

rugotut, Trilrtc* 209, 218, 221 : pi. 33

Ruhr area, Germany, coal balls 206

Russian coal balls 206

Samples, description 217-222

Son tabella sp 209

Schitodut sp. .................... 208

Schltckgerolle 213

Schopf, J. M„ quoted 21 1

Scolnoptcrit 220. 221 ; pi. 33

minor. .................. 221 : pi. 33

Scott, Paul W., analyst 207

Secor coal 194. 196. 197, 206. 207. 218

ScIoginrUiirt pi. 33

Srptimyalina sp .... 208 : pi. 34

Reptopora sp. ...... .......... — .. 208

Serpuloptit 208, 2M, 219

inuita 208

sp 208: pi. 33

Shantlclla, stetnkern. ......... 208

»p. ...... ........ 208 : pi. 34

Solachll 209

Page

Spothognathodut minutue 209; pi. 34

Spectroscopic analysis 206

Spcnccritporitei sp 209.

218, 219,220,221,222 : pi. 33

Spicule, bexactlnellld... 208

Spirorbit sp 208; pi. 34

Spore, resembling Lyconpora 209

Stelnkern Donaldina sp 209

Shantlclla 208

Stigmaria 22Q ; pi. 27

Stratigraphic relations, coal balls at

West Mineral, Kane 200-201

Strtptognathody elcgantu tut.. 209; pi. 34

tubacodn , Roundya .... 209

Subulltld 209; pi. 34

tuperbut, Trilelet 209.

210, 214, 218. 219 ; pi. 33

Tetrataxt* pauperata 208 ; pi. 34

texana, Bairdio 209

Thurommina 208. 210

rtctangulario 208

sp 208 : pi. 34

Thurammlnoldra sp 203

Trepostomatons bryosoans 208

trlangulatut. Tritely 209,

218. 219. 220. 221 ; pi. 33

Triletet

209.

210, 214. 218. 219. 220. 221,
222 ; pis. 8L 33.

auritut 209. 218. 219. 220. 221 ; pi. 31

grondit 209.

212.218. 221. 222 : pi. 33

glabratut 209. 212. 221. 222 ; pi. 33

rugotut 209. 218, 221 ; pi. 33

tuperbut ... 209.

210.214. 218. 219: Pl. 33
trlangulatut 209.

218.219,220,221 :pl.33
sp 209

rarlus, Cyttotporltet.. 209. 218. 221 : pl. 33

Welsh coat beds ............ 21S

West Mineral. Kans., coal balls 199- 201.

206. 207. 218. 219: pis. 27,
28,29.

Whitehead. W. L., quoted — 211

Yorkshire, Kngland, coal balls 194

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PLATES 26-34

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PLATE 26

Figure 1 . Closeup of channeling in coal bed at Berryville, III. Several coal balls may be seen to the right of and below the hammer.

2. A large coal ball mass overlying 4 inches of coal at Berryville, III. Part of this mass may be seen in the lower left corner

of figure 3.

3. General view of the Berryville, IU., locality. The channel and swelling of the overlying limestone is shown at left center

of photograph, above stream level. Section was measured along trench at right of photograph.

4. A part of one of the piles of coal balls near the tipple of the Pittsburg and Midway Coal Co., West Mineral, Kans.

5. View of Bevier coal in Apex-Compton Coal Co. strip pit near Monmouth, Kans., showing two faunal coal balls in place,

(at arrows), overlain by more than an inch of coal. Irregularly shaped coal ball directly above light meter, with
tabular specimen to left. Flat specimen also shown in figure 6; sawn surfaces of both specimens shown in plate 32.
Photograph by R. W. Baxter, University of Kansas.

6. View of Bevier coal taken a few minutes prior to figure 5, showing the flat faunal coal ball when first exposed. Arrow to

left of light meter points to upper surface of coal seam; tabular coal ball below and to right of arrow. Photograph by
R. W. Baxter, University of Kansas.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 344 PLATE 36

VIEWS AT THE BERRYVILLE, ILLINOIS. WEST MINERAL. KANSAS. AND MONMOUTH,

KANSAS. COAL BALL LOCALITIES

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PLATE 27

[Photographs natural site unless otherwise shown)

Figure 1. Sawn surface of a normal coal ball from Berry ville, III., showing layered appearance of plant debris, primarily fern
roots. Specimen 9190-31 C.

2. Enlargement of part of specimen illustrated in figure 3, showing cross section of high-spired gastropod. X 3.

3. Sawn surface of small homogeneous-mixed coal ball from West Mineral, Kans., containing primarily plant debris, with

gastropods scattered at random through the ball. Enlarged area indicated by arrow. Specimen 9189-123A.

4. Sawn surface of homogeneous-mixed coal ball from West Mineral, Kans., showing well-defined swirled texture and,

locally, alinement of shell fragments parallel to swirls. The fossils are predominantly animal, but a large stigmarian
stele is shown at left center of photograph. Specimen 9189-121C.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 354 PLATE 27

NORMAL AND MIXED COAL BALLS FROM ILLINOIS AND KANSAS

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PLATE 28

iPbotoernptu natural size)

Figure 1. Sawn surface of faunal coal ball from near Monmouth, Kans., showing lenticular shape and abundant pyritized animal
debris. Specimen 9487 -1A.

2. Sawn surface of normal coal ball from West Mineral, Kans., showing lenticular shape. Plant debris consists predomi-

nately of cordaitean leaves, stems, and fructifications. Specimen 9189-801).

3. Sawn surface of homogeneous-mixed coal ball from West Mineral, Kans. Organic content predominately plant debris

that includes well-preserved cordaitean organs. Some marine gastropod shells indicated by arrows. Specimen 9189-
120C.

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GKO LOGICAL SURVEY

PROFESSIONAL PAPER SM PLATE 28

FAUNAL, MIXED. AND NORMAL COAL RALLS FROM WEST MINERAL AND MONMOUTH, KANSAS

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PLATE 29

(Photograph* natural »lra unless otherwhto shown]

Figure 1. Sawn surface of homogeneous-mixed coal ball from West Mineral, Kans.; coal ball composed predominately of plant
material that includes well-preserved cordaitean seeds. Orthoceroid cephalopod and gastropods indicated by arrows.
Specimen 9189-122A.

2. Enlargement of part of specimen illustrated in figure 3, showing associated plant and animal remains. Cross section of

a gastropod shell and a ptcridophyllous pinnule indicated by arrows. X 4.

3. Sawn surface of a homogeneous-mixed coal ball from West Mineral, Kans., showing mixture of plants and animal remains.

Specimen 9189-124C.

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PROFESSIONAL PAPER 354 PLATE 29

HOMOGENEOUS-MIXED COAL BALLS FROM WEST MINERAL, KANSAS

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PLATE 30

[Photographs natural olio)

Flo u be 1 . Sawn surface of a heterogeneous-mixed coal ball from Berry ville, 111., showing stratification of marine fossil fragments
within the large marine core. A small normal coal ball lies to the right of the photograph. The layering of plant debris
in the normal coal ball and the normal part of the mixed coal ball are approximately at right angles to one another.
Specimen 9190-lE.

2. Sawn surface of a hctcrogeneous-inixed coal ball from Berryville, 111. The layering of the normal part is at right angles

to the bottom of the plate. Specimen 9190-13E. Part of this specimen was dissolved as sample E-26.

3. Sawn surface of a heterogeneous-mixed coal ball from Berryville, 111., showing an irregular marine core. The black line

above the core is a coal film. Specimen 9190-17D. Part of this specimen was dissolved as sample E-27.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER 3M PLATE 30

HETEROGENEOUS-MIXED COAL BALLS FROM BERRYVILLE. ILLINOIS

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PLATE 31

( Photographs natural size unless otherwise shown)

Figure 1.
2 .

6 .

Sawn surface of heterogeneous-mixed coal ball from Berr.vville, 111., showing discrete nature of core of marine material
with abundant animal debris, and complete enclosure of core within normal coal ball material. Specimen 9190-2F.

Broken surface of a homogeneous-mixed coal bull from Oskaloosa, Iowa, showing well-preserved plant debris. Corduitean
axis at upper left; gastropod shell indicated by arrow. Specimen 1002B. X 3. Part of this coal ball was dissolved as
sample E-13.

Piece of limestone from Berryville, III., composed of coal-ball-likc particles. The dark bands are streaks of coal.
Specimen 9190-57. Part of this specimen was dissolved ns sample E-15.

Part of sawn surface of homogeneous-mixed coal bull from Oskaloosa, Iowa. Several gas tro) tods indicated by arrows.
Part of this specimen illustrated in figure 2.

Photomicrograph of thin section cut from specimen shown in figure 3. Irregular angular and rounded particles of cal-
careous coal-ball-like material are tightly packed and interpenetrating. Traces of original plant tissue are still visible
within the replacing cnlcitc. Sections of two uncompressed megns|>ores, probably Triletes auritus, are shown at right.
X 10.

Same as figure 5, taken between crossed nicols. Calcite replacement shows up as fibrous, radially arranged crystals
that superficially resemble spheralites.

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PROFESSIONAL PAPER » PLATE 31

MIXED COAL BALLS FROM ILLINOIS ANI) IOWA, AND LIMESTONE FROM ILLINOIS

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PLATE 32

(Photographs natural site]

Figure 1. Part of sawn surface of faunal coal ball from the Bevier coal, near Monmouth, Kans., shown in place in figures 5 and 6 of
plate 20. Animal fossils exposed include sections of brachiopods and of gastropods and of a coral. Note adherent coal
on upper and lower surfaces, and included coaly stringers. Specimen shown in original attitude. Specimen 9487-2E.

2. Remainder of same specimen shown in figure 1, the two pictures overlapping slightly. Black particles in left center are

fusinized wood.

3. Sawn surface of faunal bnll from the Bevier coal, near Monmouth, Kans., shown in place to right in pi. 20, fig. 5. The

specimen is almost completely replaced by pyrite, but scattered shell fragments are visible. Specimen shown in original
attitude. Spccimeu 94S7-3A.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER SW PLATE S*

FAUNAL COAL HALLS FROM MONMOUTH. KANSAS

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PLATE 33

|AU photographs made with reflected light cxoept as Indicated]

Figures 1-24. Spores, mostly uncompressed, and spore contents from mixed coal ball residues.

1, 2. MonoleUs ovalus Schopf.

Proximal and distal surfaces, X 15; from residue E-3 (marine core of heterogeneous-mixed coal ball,
Berryville, III.); USNM 41177 (fig. 1), 41178 (fig. 2).

3, 4. Triletes glubralus Zerndt.

Proximal and distal surfaces, X 10; from residue E-2G (marine core of heterogeneous-mixed coal ball.
Berryville, 111.); USNM 41179 (fig. 3), 41180 (fig. 4).

5-10. TriUtes cf. T. superbus Bartlett.

Ail specimens from residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.).

5. Proximal surface of specimen denuded of equatorial frill, X 15, USNM 41181; 6, proximal surface of
nearly complete specimen, X 15, USNM 41182; 7, distal surface, X 15, USXM 41183; 8, calcareous
filling of spore cavity, proximal surface, X 15, USNM 41184; 9, pyritic filling of spore cavity,
proximal surface, X 15, USNM 41185; 10, fragment of proximal part of cndosporal membrane
dissected from spore, showing numerous round dark bodies, possibly mcgagamctophvtic remains,
transmitted light, X 100; USNM 41186.

1 1-14. SpencerisporiUs sp.

All specimens from residue E-28 (marine core of heterogeneous-mixed coal ball, Berryville, III.) .

11. Proximal surface, X 75, USNM 41187; 12, distal surface, X 75, USNM 41188; 13, specimen photo-
graphed with transmitted light from proximal side, X 70, USN M 41189; 14, specimen photographed
with transmitted light from distal side, X 70, USNM 41190.

15-17. TriUtes aurilus var. grandis Zerndt.

All specimens from residue E-26 (marine core of heterogeneous-mixed coal ball, Berryville, 111.).

15. Proximal surface, X 20, USNM 41191; 16, distal surface, X 20, USNM 41192; 17, lateral view of
specimen broken along two rays of trilete suture, showing hollow nature of uncompressed spore,
thick exospore, and thin endospore, somewhat separated from exospore, X 20, USNM 41193.
18-19. TriUtes cf. T. rugosus (Loose) Schopf.

Both specimens from residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.).

18. Lateral view of partly split but uncompressed specimen, X 30, USNM 41194; 19, lateral view of
compressed specimen with segments of apical vestibule separated from each other, USNM 41195.
20. CyslosporiUs varius (Wieher) Dijkstra, X 20.

Apical view of abortive specimen showing spongy pyramidal structure at apex of spore. From residue
E-31 (homogeneous-mixed coal ball, McAlester, Okla.), USNM 41196.

21-22. Triletes triangulatus Zerndt.

Both specimens from residue E 13 (homogeneous-mixed coal ball, Oskaloosa, Iowa).

21. Lateral-distal view, X 45, USNM 41197; 22, proximal surface, X 45, USNM 41198.

23-24. Parasporilts cf. P. mae-.ubei Schopf.

Both specimens from residue E-3 (marine core of heterogeneous-mixed coal ball, Berryville, 111.).

23. Distal surface, X 45, USNM 41199; 24, proximal surface, X 45, USNM 41200.

25-36. Uncompressed plant parts and foraminifer-enemsted plant material from coal ball residues.

25-26. Fragments of fusinized wood, with adherent tests of Serpulopsis sp., X 25.

From residue JB— 23 (homogeneous-mixed coal ball, West Mineral, Kans.), USNM 41201 (fig. 25), 41202
(fig. 26).

27. Denuded specimen of Triletes cf. T. superbus, with adherent test of Serpulopsis sp., X 10.

From residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 41203.

28. Fragment of specimen of Triletes cf. T. superbus, with test of Serpulopsis sp. adherent to inner surface, X 25.

From residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 41204.

29. Oblique-lateral view of specimen of TriUtes cf. T. superbus, with test of Serpulopsis sp. adherent to median

ray of trilete appendage, X 10.

From residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 41205.

30. Oblique-lateral view of specimen of Triletes cf. T. superbus, with two adherent tests of Serpulopsis sp., X 10.

From residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 41206.

30a. Same spore, enlarged to X 25, showing conformity between Serpulopsis test and sinuosity of right-hand

ray of trilete appendage of spore.

31. Uncompressed conostomalean seed (cf. Coronostoma Neeley), X 15.

From residue E-19 (norma! coal bull, Berryville, III.); USNM 41207.

32. Uncompressed fusinized lycopod brunchlet with ultnehed leaves (cf. Sclaginellitcs), X 15.

From residue E-23 (homogeneous-mixed coal bull, West Mineral, Kans.); USNM 41208.

33. Apical view of uncompressed fusinized scolccopterid fern synangium (cf. Scoleeopteris minor Hoskins.,

X 30.

Tips of sporangia are broken away, showing hollow sporangial cavities. From residue R-19 (normal
con) ball, Berryville, HI.); USNM 41209.

34. Fusinized fragment of uncompressed fern pinnule, bearing scolccopterid synangium at right, X 30.

From residue E-19 (normal coal ball, Berryville, 111.); USNM 41210.

35. Lateral view of uncompressed fusinized scolccopterid fern synangium, X 30.

From residue E-19 (normal coal ball, Berryville, III ); USNM 41211.

36. Apical view of uncompressed fusinized scolccopterid symtngium composed of four sporangia, X 30.

From residue E-19 (normal coal ball, Berryville, 111.); USNM 41212.

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GEOLOGICAL SURVEY PROFESSIONAL PAPER 364 PLATE S3

REPRESENTATIVE SPORES AND OTHER PLANT REMAINS RECOVERED FROM INSOLUBLE RESIDUES

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PLATE 34

(Explanation of figtuts 30-47 follow plate 34)

Figure 1, 2. Telraiaxis paupcralal (Warthin), X 25.

From residue E-7, (faunal coal ball, Monmouth, Kans.); CSX M 02851 8a, b.

3. Olobivalvulma sp., X 25.

From residue E-31 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 028519.

4. Apterrinetta sp., p.vritic cast of undivided, tubular chamber, X 25.

From residue E-29 (heterogeneous-mixed coal ball, Berry ville, 111.); USXM 028520a.

5. Thurammina sp., X 25.

From residue E-27 (heterogeneous-mixed coal ball, Berryville, HI.); USXM 028521.

0. AmmoverUlla sp., X 50.

From residue E-28 (heterogeneous-mixed coal ball, Berryville, 111.); USXM 028522.

7. Fusulinid indel., X 25.

From residue E-31 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 138848.

8. Aplerrinella sp., with adherent sponge spicule near left end of tube, X 25.

From residue E-29 (heterogeneous-mixed coal ball, Berryville, 111.); USXM 028520b.

9, 10. llexactinellid sponge spicules, X 30.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, 111.); USXM 138849a, 138849b.

11. Pennirelepura sp., X 8.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, III.); USXM 138850.

12. Crinoid columnal incrusted by foratninifer, X 10.

From residue E-7 (fauna) coal ball, Monmouth, Kans.); USNM 138851.

13. Rhombopora sp., X 10.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, III.); USNM 138852.

14. Polypora sp., X 4.

From residue E-25 (hcterogcncous-mixcd coal ball, Berryville, 111.); USNM 138853.

15, 16. Penestella sp., X 10.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, III.); USNM 138854a, b.

17. Linguloid brachiopod, X 20.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138855.

18. Orbiculoid brachiopod, X 10.

From residue E 22 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 138856.

19. Derby ia sp., X 2.

From residue El-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 138857.

20. Marginifera sp., X 2.

From residue E-23 (homogeneous-mixed coal ball, West Mineral, Kans.); USNM 138858.

21. Mcsolobus sp., exterior, X 8.

From residue E-l (homogeneous-mixed coal ball, Franklin, Kans.) ; USNM 138859.

22. Septimyalina sp., interior, X 10.

From residue E-31 (homogeneous-mixed coal bail, McAlester, Okla.); USXM 138860.

23. KnighliUs (Relispira) sp. X 5.

From residue E-20 (homogeneous-mixed coal ball, Monmouth, Kans.); USNM 138861.

24. Eucochlie sp., X 20.

From residue E-28 (heterogeneous-mixed coal ball, Berryville, III.); USXM 138862.

25. Pakottylus ( Pseudotygopltura ) sp., X 12.

From residue E-7 (faunal coal ball, Monmouth, Kans.); USXM 138863.

26. Shantiella sp., X 20.

From residue E-7 (faunal coal ball, Monmouth, Kans.); USXM 138864.

27. Parallelodon sp., X 15.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 138865.

28. Permophorus sp., X 10.

From residue E-31 (homogeneous-mixed coal ball, McAlester, Okla.), USXM 138866.

29. Pseudorthoceras knozeme (McChesney), X 4.

From residue E-31 (homogeneous-mixed coal ball, McAlester, Okla.), USXM 138867.

30. Borestus sp., X 3.

From residue E 20 (homogeneous-mixed coal ball, Monmouth, Kans.); USXM 138868.

31. Subulitid indet., slightly oblique, apertural view. X 15.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 138869.

32. Donaldma sp., X 8.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, 111.; USXM 138870.

33, 34. Coprolitic pellets of unknown organism, X 20.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138821a, b.

35. Arabellitex sp., X 20.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USXM 138872.

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GEOLOGICAL SURVEY

PROFESSIONAL PAPER S»l PLATE M

REPRESENTATIVE ANIMAL REMAINS RECOVERED FROM INSOLUBLE RESIDUES

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Figure 36. Spalhognathodm minutut T (Ellison), X 30.

From residue E-25 (heterogeneous-mixed coal ball, Berryville, 111.); USN M 138873.

37. Osarkodina dclicatula (Stauffer and Plummer), X 30.

From residue E-4 (heterogeneous-mixed coal ball, Berryville, 111.); USNM 138874.

38. "Spirorbti" sp., X 20.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138875.

30-41. Free cheek, fragment of pygidium, and cephalon, respectively of ? Dilomopygc sp., X 8.

From residue E-26 (heterogeneous-mixed coal ball, Berryville, 111.); USNM 138876a, b, c.

42. Hindcodtlla sp., X 30.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138877.

43. Idiognathodus magnificus Stauffer and Plummer, X 30.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138878.

44. Slreplogmthodus ctegarilulus Stauffer and Plummer, X 30.

From residue E-29 (heterogeneous-mixed coal ball, Berryville, III.); USNM 138870.

45. Gnalhodus basslcri (Harris and Hollingworth), X 30.

From residue E-13 (homogeneous-mixed coal ball, Oskaloosa, Iowa); USNM 138880.

46. “Spirorbis" sp. incrusted with foraminifers, X 20.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138881.

47. Hollinella sp., X 30.

From residue E-l (homogeneous-mixed coal ball, Franklin, Kans.); USNM 138882.

48. Arnphissiles cenlrnnolut (Ulrich and Bossier), X 30.

From residue E-29 (heterogeneous-mixed coal ball, Berryville, HI.); USNM 138883.

49. Bairdiacypris sp., X 30.

From residue E-29 (heterogeneous-mixed coal ball, Berryville, 111.); USNM 138884.

50. Bairdia sp., X 30.

From residue E-29 (heterogeneous-mixed coal ball, Berryville, III.); USNM 138885.

51. Glyptopleura sp., X 30.

From residue E-l (homogeneous-mixed coal ball, Franklin, Kans.); USNM 13888G.

52. Actinoptcrygii: palaconiscoid fish scale, X 10.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138887.

53, 54. Cladoidachii: cladodont shark scales, X 10.

From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138888a, b.

55-57. Actinoptcrygii: cranial roofing element, vertebra, and lower jaw fragment, respectively, of palaeoniscoid fish, x 10.
From residue E-22 (homogeneous-mixed coal ball, McAlester, Okla.); USNM 138889a, b, c.

L'.S. GOVEHNMKNT MltXTtNG or KK'1) : |M o -5bi66i

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Lituyapecten (New Subgenus of
Patinopecten ) From Alaska and
California

AND

Stratigraphic Occurrence of
Lituyapecten in Alaska

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-J,K

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961

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UNITED STATES DEPARTMENT OF THE INTERIOR
STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY
Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.

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Lituyapecten (New Subgenus of
Patinopecten) From Alaska and
California

By F. STEARNS MacNEIL

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 3S4-J

New Miocene and Pliocene species from Alaska
show the relation of a known unique Miocene species
from Alaska to previously know?t Pliocene species
from California , a7id a new subgenus is proposed
for them

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CONTENTS

p»*t

Abstract 22j

Introduction 225

Systematic paleontology 225

Genus Patinoptcten Dali. 1898 225

Subgenua Lituyapeclen MacNeil, n. subgen 227

Patinoptcten ( Lituyapeclen ) poulcreekenaie

MacNeil. n.8p 228

Patinoptcten ( Lituyapeclen ) poulcreekeneis

MacNeil, subsp.? 229

Patinoptcten ( Lituyapeclen ) yakalageneie (Clark) - 229

Patinoptcten ( Lituyapeclen ) cf. P. (£>.) yakata-

aensis (Clark) 231

Patinoptcten (Lituyapeclen) lituyaeneie MacNeil.
n. ap_ 231

Systematic paleontology — Continued

Subgenua Lituyapeclen MacNeil. n. subgen — Con.
Patinoptcten (.Lituyapeclen) purisimaensis (Ar-
nold)

Patinoptcten ( Lituyapeclen ) faloreneie MacNeil.

n. sp

Patinoptcten ( Lituyapeclen ) cf. P. (L.) dilleri

(L»M)

Patinoptcten (Patinoptcten) caurinue (Gould)

Vertipecten sp. indet—

Page

233

234

235

236
236

ILLUSTRATIONS

Plate 35.
36.

37.

38.

39.

40.

41.

Pcctinida from the Poul Creek formation and
the upper part of the Katalla formation.

Pectinids from the Poul Creek formation, the
upper part of the Katalla formation, and
the uppermost Poul Creek or lpwcrmost
Yakataga formation.

Pectinids from the Yakataga formation.

Pectinids from the Poul Creek formation, the
Yakataga formation, and the Falor forma-
tion of Manning and Ogle, 1950 (Cali-
fornia).

Pectinids from the Yakataga formation and the
upper mudstone unit of the unnamed upper
Tertiary formation in the Lituya district.

Pectinids from the upper mudstone unit of the
unnamed upper Tertiary formation in the
Lituya district.

Pectinids from the Yakataga formation and
tho lower sandstone-siltstone and upper
mudstone units of the unnamed upper
Tertiary formation in the Lituya district.

Pectinids from the Yakataga formation and
the lower sandstone-siltstone and upper
mudstone units of the unnamed upper
Tertiary formation in the Lituya district.

43. Pectinids from the upper mudstone unit of the

unnamed upper Tertiary formation in the
Lituya district.

44. Pectinids from the Purisima formation

(California).

45. Pectinids from the Poul Creek formation, the

upper mudstone unit of the unnamed up-
per Tertiary formation in the Lituya dis -
trict. and from the Purisima formation
(California).

46. Pectinids from the Poul Creek formation, the

Falor formation of Manning and Ogle. 1950
(California), and the Purisima formation
(California).

[Plato follow Index)

Plate 42.

▼

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

LITUYAPECTEN (A NEW SUBGENUS OF PATINOPECTEN) FROM ALASKA AND CALIFORNIA

By F. Stearns MacNeil

ABSTRACT

A new subgeneric name, Liluyapecten, is proposed under the
genus Patinopecten (used as a subgenus of Pecten by some au-
thors) to include a small but characteristic group of large
pectinids having, usually, frill-like lamellae on the ribs of its left
valve.

Of unknown origin, the subgenus appears first in early Miocene
(or possibly very late Oligocene) beds of Alaska. It inhabited
Alaska throughout Miocene and into Pliocene time, spreading
southward into California in the Pliocene; its last survivors in
the California Pliocene may be younger than its last known rep-
resentatives in Alaska.

Three previously described species are included in Lituya-
pecten; yakatagensis Clark, purisimaensis Arnold, and dillr.ri
Dali; coosensis Shumard may be an aberrant member. Three
new species are described ; P. (L.) poulcreekensis MacNeil,
lituyaensis MacNeil, and falorcnsis MacNeil. An unnamed
possible subspecies of poulcreekensis is also recognized.

The subgenus is believed to comprise two stocks, the yakata-
gensis stock (yakatagensis, lituyaensis, falorensi s, and purisi-
maensia; coosenais may be an atypical member), and the dilleri
stock (poulcretkensis and dilleri). The last representatives of
both stocks appear to have penetrated the farthest south; P.
(£..) falortnsis is known as far south as central California where
it occurs in the Purisima formation; P. (L.) dilleri is known in
the Pliocene of northern Lower California, Mexico.

INTRODUCTION

This study was prompted by a collection made by
D. J. Miller in the sununer of 1958 of some exception-
ally well-preserved material from Yakataga Reef in
the Yakataga district, and from Cenotaph Island in
Lituya Bay, Alaska. After preparing this material
it was realized that some large Patinopecten in it were
worthy not only of description in themselves, but they
shed new light on the internal relation of a conspicuous
but poorly known group of Patinopecten occurring in
the late Tertiary of both Alaska and California. Ac-
cordingly, a restudy was made of similar forms in older
Alaskan collections as well as of related forms in
California. With one exception the specimens figured
here from Alaska are from the collections of the U.S.
Geological Survey; they will be deposited in the U.S.
National Museum. One specimen from the collection

of the California Academy of Sciences is figured. The
collections of both the Academy and the University of
California at Berkeley were used in listing the oc-
currences of species. None of the specimens from
Alaska illustrated here has been figured previously.
The bolotype of Pecten ( Patinopecten ) yakatagentds
Clark, the only Alaskan species for which an illustration
was available, is a poor specimen and is not refigured.

Related species in California Pliocene formations were
studied in connection with the Alaskan species. Speci-
mens of these species in the collections of both the
University of California and Stanford University are
illustrated here. These include the holotype of
Patinopecten (Liluyapecten) fulorenxU MacNeil, a speci-
men figured previously as “Pecten oregonensis Howe
var.” by Manning and Ogle (1950, pis. 6, 7), some
specimens of the same species from the Purisima for-
mation, and what is believed to be one of the best
specimens known of Patinopecten puriximaenxi * Arnold.

Most of the material from Alaska occurs as soft
shell in fine-grained hard rock. Complete free speci-
mens are rare and in collecting fructure takes place
most commonly through the shell material, leaving
part of the shell on the internal mold and part on
the external mold, Most of the rock is noncalcareous,
and it was found that molds having good detail could
be obtained by dissolving away the shells in acid.
Casts were made from these molds with liquid latex.
With the exception of one specimen (pi. 42, fig. 4)
that was collected as a mold filled with decaying
vegetable material, presumably dissolved naturally
by humic acids, all the rubber casts were obtained
in this way.

SYSTEMATIC PALEONTOLOGY
Genus PATINOPECTEN Dali. 1898

Type: Pecten caurinus Gould. Recent, northern
California to Alaska.

The genus Patinopecten is known only from northern
Pacific waters; its southernmost record is in Lower

225

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226

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

California. Numerous species, ranging in age from
middle Tertiary to Recent, are known from both the
North American and the Asiatic sides of the Pacific.
Only two species survive; P. eaurinus (Gould) from
the United States and P. yessoensis (Jay) from Japan.
The greatest number of species occurs in the Pliocene
and late Miocene. The present paper describes the
oldest known American species, a species occurring
in beds of early Miocene or possibly late Oligoccnc
age in Alaska. The first American species is a large
form, which, together with its abrupt appearance,
suggests that it is a migrant from elsewhere. Pos-
sibly the ancestral stock of Patinopecten is a still
unknown pectinid in the beds of early Tertiary ago
of east Asia.

One of the earliest known Asiatic species is Patino-
pecten yamasakii ninohensis Masudu (1954, p. 13,
figs. 1-3) from the Shiratori formation (early Miocene)
of Japan. It is variable enough to foreshadow several
subsequent types. Its antecedents, when they are
found, should shed some light on the origin of
Patinopeclen.

Patinopecten is at present the most likely genus in
which to place the species under consideration. How-
ever, it is by no means certain that Liluyapecten,
the subgenus here proposed to include the pectens
of the P. yakatayensis group, really is a subgenus of
Patinopeclen. We still know too little about the
exact lines of descent- within the highly complex
pcctinids to make definite statements.

Grant and Gule (1931, p. 188) say, “Ve riipeclen
appears to be the connecting link between (’hlamys
and Patinopeclen." Elsewhere (p. 192) they remark

This RToup of species [Patinopecten), although obviously
closely related to Chlamys and to Vtrlipeclen, is none the less,
a rather distinct unit. It represents an evolutionary adap-
tation starling in the same ircction as that taken by Amusium;
but the external ribs did not become absolute, and hence
the external lirae did not become sharp. The general shape,
however, is the same. The shape of Placopeclen is also similar.
Patinopeclen developed distinct external ribs, Placopeclen re-
tained but faint radial riblets on the exterior, while all that
is left of the ribs of Amusium are the strengthened internal
lirae. * * * Amtuium is more closely related to Janira,
and it is possible that its apparent relationship to Patinopeclen is
superficial, being a parallel adaptation to a somewhat similar
environment.

There is strong reason for believing Grant and Gale
are correct in asstiming Amusium to be closely related
to Pecten ( Pecten ) (= Janira). In fact, there is
strong reason for believing typical Peclen (Pecten),
Amusium, and Peclen (Amussio pecten) are codcriva-
tives from a prototypical Pecten (Peclen). Peclen
(Amussiopecten) seems to form a continuum between
Pecten (Pecten) and Amusium.

However, the exact relation of Patinopecten to either
Vertipecten or Chlamys is still rather obscure. Verti-
pecten seems to be closely related to some of the types
included in Chlamys, but whether or not Chlamys as
used by most modern authors is a monophyletic group
is another matter. Certainly the left valve of the ear-
liest known North American species of Patinopecten
bears little resemblance to the left valve of coexisting
species of Vertipecten. Vertipecten is unique in having
its left valve more inflated than its right valve. It
would be premature to say Patinopecten is not related
to Vertipecten but it would be safe to say that if the
two are related they must have diverged from each
other at least as far back as early Tertiary time.

The known late Mesozoic and earliest Tertiary pec-
tinids seem to indicate that the prototype of Pecten
(Pecten) was derived from a Cawipfoncc/es-likc ancestor.
An -,-lmtmum-likc stock was also differentiated at an
early date, but it resembles true Amusium only in be-
ing smooth and probably was not the ancestor of Amu-
sium s.s. The ontogeny of Pecten (Pecten), based on
P. (P.) jacobaeus Lamarck, suggests that the proto-
typical stock may have been inequivalved but smooth.
It may have been closely related to the primitive Amu-
st'um-like smooth forms. It developed ribs to produce
Pecten (Pecten), and the ribs became secondarily obso-
lete but reinforced internally, along with flattening of
both valves, to produce Amusium s.s. The more
coarsely ribbed true pectens have well-developed rims
along the sides of the internal projection of the inter-
spaces between the ribs, presumably a stage in the de-
velopment of the pairs of riblets on the inside of both
Pecten (Amussiopecten) and Amusium. These paired
internal ribs are probably a development independent
of the single internal ribs of other externally smooth
pectinids; still others are without internal ribs. Patino-
pecten, although resembling Pecten (Amussiopecten) ex-
ternally, does not have paired internal ribs.

Very young shells of Patinopecten eaurinus are nearly
smooth with irregular radiating white lines in the shell,
resembling some species of Pseudamussium and Propeu-
mussium. They have a faint diagonal Camptonectes-
like niicrosculpturc. This, together with its lack of in-
ternal ribs, suggests a separation of the Patinopecten
branch before the stabilization of Pecten (Pecten) and
Amusium. Possibly Patinopecten came from intermedi-
ates between Camptoneetes and Pecten (Pecten).

Left valves of most specimens of Patinopecten cauri-
nus have delicate, evenly spaced raised concentric
growth lines extending to the ventral margin; on some
specimens there is a slight imbrication. Similar con-
centric growth lines arc the characteristic microsculp-
ture of the left valve of most species of Pecten (Pecten)
and of Pecten (Amussiopecten). Some of the curly true

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LITUYAPECTEN. NEW SUBGENUS, FROM ALASKA AND CALIFORNIA

227

Amusium may have had similar concentric growth lines,
but the later species of Amusium have both valves
smooth and polished. The group of Patinopecten under
consideration has fine concentric growth lines on the
early stages of the left valve, but the typical sculpture
of the left valve of adults is characterized by lamellae
or flanges which may extend entirely across the ribs or
which may be divided into two series, one along each
edge of the flat-topped ribs. The transition from the
the juvenile to the adult sculpture may be abrupt or
gradual. On some individuals the fine concentric
growth lines persist in adults in the interspaces as well
as on top of the ribs between the blunt spines or flanges.

No specimens of Lituyapecten yet observed show any
suggestion of the imbricating microsculpture, resem-
bling the surface of metal lath, that characterizes
left valves of Chlamys, Vertipecten, Fortipecten, and
some species of Patinopecten such as P. yessoensis,
P. propatulvs (Conrad), and P. ibaragiensis Masuda
(1953), pis. 5, 6); imbricating microsculpture occurs
rarely in small patches on specimens of P. caurinus.
On the other hand, P. coosensis (Shumard) (sec Trum-
bull, 1958, pis. 115-117), a species generally referred
to Patinopecten s. s., has a concentric microsculpture,
not an imbricating one.

It may be that P. coosensis is really a flangeless
Lituyapecten, not a member of the P. ( Patinopecten )
caurinus group. In support of this, a flangeless variant
of P. (L.) yakatagensis (pi. 45, fig. 3; pi. 46, fig. 5),
whose left valve ribs are squared like those of P.
coosensis, has only fine concentric growth lines all
the way to the ventral margin. These two species
also have a peculiar strong fold on the anterior ear of
the left valve.

The origin of Fortipecten was discussed by Yabe and
Hatai (1940, p. 153-155). Yabe and Hatui suggested
that some Miocene Patinopecten might be the ancestor
of this subgenus. Since their paper was written, a
Miocene species has been described, Patinopecten
ibaragiensis Masuda (1953, p. 44, pi. 5, figs. 1-5; pi. 6,
figs. 1-5), which definitely seems to be the connecting
link between Patinopecten and Fortipecten. I am
inclined to regard Fortipecten as a subgenus of Pat-
inopecten on the basis of this species. The genus
Patinopecten would then embrace three subgenera:
typical Patinopecten, Fortipecten, and Lituyapecten.

If an imbricating mocrosculpture is a primativc
character that persists in several lines of descent such
as Chlamys (Chlamys), Chlamys ( Swijtopecten ), Chlamys
of the C. berinyianus group, Vertipecten, and Patino-
pecten), it is difficult to see why it is present in some
typical Patinopecten and not in others. The micro-
sculpture is developed in a layer that is readily de-

corticated, and it is only seen on exceptionally well-
preserved specimens; sometimes only a small patch of
it can be found. As far as is known, only concentric
microsculpture is found in Amusium, Pecten (Amussio-
pecten, Pecten (Pecten), and Patinopecten ( Lituyapecten ).

It is entirely possible that Patinopecten inherited an
imbricating microsculpture which, although persisting
in Fortipecten and in some species of typical Patino-
pecten, was eliminated in some typical Patinopecten
and in Lituyapecten. It is also possible that there was
no persistence of this character in the phylogenetic
lines connecting Patinopecten with Vertipecten and
Chlamys, however short or long they might have been,
and that this character was redeveloped in some
branches of Patinopecten. At any rate, our present
imperfect knowledge of pectinid phylogeny makes it
impossible to settle the question.

Subgenus LITUYAPECTEN MacNeil, new subgenus

Type: Patinopecten (Lituyapecten) lituyaensis Mac-
Neil, n. sp.

Diagnosis. — Shell medium large to very large; a
right valve of the type species measures 8 K inches in
diameter; this size makes it one of the largest pectinids
known. Outline ranges from subrounded to elliptical;
long axis in some species is the height; in others, the
length. Ears moderately large; byssal notch moderately
strong to strong; anterior ear of right, valve elongate,
tends to become narrower, and curves ventrally in
full grown adults; left valve ears more symmetrical,
and anterior car tends to develop a marginal fold
(concave on the inside) opposite narrow ear of right
valve. Ribs strong, and those of right valve moderately
broad to broad; they tend to be undercut on sides,
flat to rounded or irregular on top. Interspaces
usually deep and round bottomed. Juvenile sculpture
consisting of thin concentric raised lines.

Interstitial ribs may occur on either valve and they
are usually beset by a single row of rounded frills or
flanges. Right valve of Lituyapecten probably slightly
more inflated than left valve. Crushing of known
specimens makes it difficult to determine the relative
inflation; certainly some known left valves more in-
flated now than right valves. Hinge plate relatively
heavy and with a single nearly marginal groove in each
of the left valve cars. Base of the hinge plate
conspicuously swollen.

Discussion. — The subgenus is founded primarily on
the left-valve sculpture. The ribs are moderately
narrow to wide and rounded to flat topped. The
juvenile sculpture consists of raised concentric growth
lines that are fine and evenly spaced; they are similar to
those normally covering the entire valve of P. caurinus.

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228

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

The adult sculpture of Lituyapeden consists of sharply
raised flanges or lamellae, which may be single or
divided into two or more rows of segments.

I am indebted to Mrs. Ellen Trumbull, of the U.S.
Geological Survey for a photograph of an unusually
well-preserved specimen of Patinopeden propatulus (Con-
rad) from the Astoria formation (Miocene) of Oregon,
a specimen which she will figure in a forthcoming paper.
This specimen has several patches of imbricating
microsculpture preserved. In addition, it has small
frill-like flanges very close to the beak on three or four
of the posterior ribs of the left valve. They are closer to
the beak than I have seen them on other species having
similar flanges, and they appear to have died out at the
stage of growth at which they normally appear in other
species. This specimen contains the only combination
of imbricating microsculpture and frill-like flanges I
have seen. On the basis of the frills alone, P. propatulus
might appear to belong to Lituyapeden , even though
the frills occur at a different growth stage than is
common. I am inclined to believe that the juvenile
frills on P. propatulus indicate that typical Patinopeden
and Lituyapeden are closely related after all, some-
thing that I did not feel I could say positively from
other species. Possibly P. ( Patinopeden ) and P.
(Lituyapeden) diverged from each other in Oligocene
time. P. propatulus certainly seems to be a typical
Patinopeden, whereas I believe coosensis is an aberrent
Lituyapeden.

Clark (1932, p. 808) in his description of Peden
(Patinopeden) yakatagensis said: “ Peden yakatagensis
of all the species referable to the subgenus Patinopeden is
unique. * * * It is very possible that Peden yakata-
gensis should be placed in a new section.” T'ne new
subgeneric name, Lituyapeden, is here proposed to
include the species of Patinopeden having one to several
rows of frill-like flanges on the ribs of the left valve.

Two groups of species are included under Lituy-
apeden, t he Patinopeden dilleri group and t he Patinopec-
ten yakatagensis group. The P. dilleri group usually
has subrounded ribs on the left valve and single flanges
continuous across the ribs; rarely the flanges may be
divided on one or two of the central ribs with the dis-
connected segments of the flanges alternating. In the
P. yakatagensis group the flanges are broken up into
two or more well-defined series located on ribs, which
at least in full grown adults tend to be broad and flat
topped. Two rows of short spinelike flanges, one along
each side of flat-topped ribs, is the most common con-
dition. However, the distinction of the flanges as
single or multiple rows is sharp only in the Pliocene
species, the last-known members of the group. The
earliest known members are irregular in the division or
nondivision of the flanges and in the distance of separa-

tion; the same specimen may have single or divided
flanges on different ribs, or on different parts of the
same rib. Thus, while the end members of these two
groups may seem quite distinct, the earliest representa-
tives indicate that they had a common ancestry and
that the characters which distinguished their last-
known representatives were characters of no more than
individual variation in their earliest known representa-
tives.

Lituyapeden commonly has large barnacles on its
left valve, but none have been observed on right
valves. (See pi. 37, fig. 7; pi. 42, fig. 3; pi. 43, figs.
1, 4.) Presumably it rested on its right valve. If
they were active, specimens with large barnacles
must have had their activity impeded; some barnacles
on Alaskan specimens have bases measuring over 30
millimeters. The Geological Survey collection con-
tains a Recent specimen of Patinopeden (Patino-
peden) caurinus whose right valve is clean but whose
left valve is covered by barnacle bases. Schools of
this species are believed to move from location to
locution periodically.

As far as is known, Lituyapeden is typically North
American. The known species are till from Alaska
and California; apparently it never invaded Asiatic
waters. It ranges from early Miocene, possibly late
Oligocene, to late Miocene, possibly early Pliocene
in Alaska. The California occurrences are Pliocene.

Patinopecten (Lituyapccten) poulcreekensis MacNoil, n. sp.

Plate 35, figures 1-6; plate 36. figures 1, 2(T), 3, 4, 6, 7;
plute 38, figure 2

Shell moderutely large, suborbiculur; valves probably
both moderately inflated, right valve possibly more
so (inflation varies in specimens at hand, probably
owing to crushing); shell of medium to above medium
thickness. Dorsal margins straight to weakly concave;
dorsal margins low and have a poorly defined sub-
marginal slope. No visible denticles along margin
of bvssal sinus. Dorsal margin of ears straight.
Ears moderately large; bvssal sinus moderately deep
and large; ears sculptured by strong rudiul riblets
(about six) which ure made scaly or frilled bv the
strongly upturned edges of closely set growth lines,
the scalincss being strongest on the ribs; posterior
ears of both valves have concave terminal margin
with hinge line shorter than base of ear; anterior ear
of left valve has convex terminal margin. Both
valves with about 22 strong radial ribs and 1 or 2
additional minor ribs at both ends of valve; ribs of
right valve more squared and undercut; ribs of left
valve more rounded; a few ribs partly to completely
bifurcating, a median cleft on 1 or 2 ribs being rather
common. Ribs of right valve broad and range from

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LITUYAPECTEN, NEW SUBGENUS,

smooth and flat to irregular and bear 2 or 3 secondary
radial ridges of moderate strength; central ribs smooth,
but the terminal ribs at both ends may have weak
frills along one or both sides or single frills extending
entirely across them; interspaces have moderate to
strong interstitial ribs which, when not decorticated,
are strongly frilled. Left valve has regular closely
set raised growth lines in early stages; growth lines
change abruptly to a stage having raised frills or
flanges, the earliest being single and continuous across
the ribs or, at most, divided into two series by a
median discontinuity; flanges on opposite sides ure
often staggered or alternating, especially when first
appearing, but are more often at the same position
in later stages. In full-grown adults, frills may
range from a single row to 2 rows with very narrow
separation to 4 rows formed by division of double
rows. Interspaces also have a moderately strong,
highly frilled midrib; a few interspaces have two
such interstitial ribs. F'rills fragile and easily de-
corticated ; best examples obtained as latex impressions
after acid preparation. Right-valve microsculpture
not detected and presumably smooth.

Holotype, a right valve (USNM 563572), measures:
diameter 113 mm, height 113 mm. Largest right
valve on hand has a height of 145 mm, to which must
be added a few more millimeters for wear. Paratype,
USNM 563573.

This species has not been found outside of the Yaka-
taga and Katalla districts, Alaska. It is known to
occur abundantly only in the uppermost part of the
Poul Creek formation at Yakataga Reef, although a
few fragments of it are known from rocks of nearly the
same age at a few other localities. If the supposed
stratigraphic position of the youngest known specimen
in the Katalla district is correct, it ranged into beds
equivalent to the lowermost part of the Yakataga
formation, and was presumably coexistent with the
early members of P. (L.) yakaiagensis. The specimen
in question, an extreme variant, is figured on plate 35,
figure 6. One specimen (pi. 36, fig. 2), while from an
isolated locality in the Suckling Hills (USGS 15843)
whose stratigraphic position is in some doubt (see,
Miller, p. 242), is believed, nevertheless, to be the oldest
specimen collected, and it may be the oldest Patino-
pecten yet collected from North America; a late Oligo-
cene age is possible.

Patinopecten ( Lituyapecten ) poulcreekensis will be
compared with P. (Z,.) yakaiagensis under the discus-
sion of the latter species.

The known relatives of P. {L.) poulcreekensis all
occur in younger beds in Alaska and California. Noth-
ing similar to it is yet known from equivalent beds

FROM ALASKA AND CALIFORNIA 229

elsewhere, and its ancestors and regional provenance
are unknown.

Distribution. — Karly Miocene, northern Gulf of Alaska region:
Katalla formation (upper part), Katalla district; Poul Creek
formation (uppermost part), Yakataga district, Alaska.

Type locality. — Uppermost part of the Poul Creek formation
at Yakataga Reef, USGS loc. M-271.

Other occurrences. — Katalla formation, upper (?) part, USGS
15842 (float), USGS 15852. Poul Creek formation, USGS
17733, CAS 29261, ?292C4.

Patinopecten (Lituyapecten) poulcreekensis MacNeil, subspf
Plate 36, figure 5; plate 38, figure 5.

Two incomplete specimens from near the Poul C'reek-
Yukatagti formation boundary, but whose exact forma-
tional position is not known, are unique in having some
sculptural details like P. ( L .) poulcreekensis, some
sevdpture intermediate between P. ( L .) poulcreekensis
and P. (L.) yakaiagensis, and narrower and more
numerous ribs, agreeing in this respect more with
P. (L.) yakaiagensis. They could well represent linear
intermediates between the two species, but at the same
time they are typical of neither. The earliest growth
stage on one fragment shows it to have concentric
raised growth lines like juveniles of poulcreekensis and
yakaiagensis. Interstitial ribs with moderately strong
flanges are present in some of the interspaces, agreeing
in this respect with poulcreekensis.

The prevalence in this form of single strong flanges
completely crossing the ribs suggests that it may be
ancestral to the P. ( L .) dilleri group, of which group a
fragment obtained high in the section in the Lituya Bay
district is believed to be a member (pi. 45, fig. 4; right
valves on pi. 41, figs. 4, 5).

This form is not being named at present, although
with better preserved material it probably would be.
It seems likely that this form and typical P. (L.) poul-
creekensis had a common ancestry but arc at least sub-
specificallv distinct. If this form and the one from the
Suckling Ilills (pi. 35, fig. 6) were end members of the
same population it would be variable indeed.

The largest fragment figured (CAS 29285) has a
diameter of 118 mm, a fraction of the whole dimension.

Distribution. — Karly Miocene, uppermost part of the Poul
Creek formation or the lowermost part of the Yakataga forma-
tion, Yakataga district, Alaska.

Localities. — CAS 29285; USGS D341 (T).

Patinopecten (Lituyapecten) yakatagensis (Clark)

Plate 37, figures 1-7; plate 38, figures 4, 6; plate 39, figure 2;
plate 41, figures 2(?), 3; plate 42, figure 3

Pcclen ( Patinopecten ) yakaiagensis Clark, 1932, Geol. Soc. Amer-
ica Bull., v. 43, no. 3, p. 807, pi. 15, fig. 8, pi. 16, fig. I.

Shell of medium size, suhorbicular; valves both mod-
erately inflated; left valve possibly less inflated than

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230

SHORTER CONTRIBUTION'S TO GENERAL GEOLOGY

right valve; shell moderately thin. Dorsal margins
weakly concave, low with weak submarginal slope on
left valve; right-valve ears swollen; this condition
makes boundary between earn and disk a sharp, nar-
row groove. No byssal denticles. Dorsal margin of
ears straight to vent rally depressed at the terminal
ends. Ears moderately flat but moderately elongate;
byssal sinus large and deep, wider than terminal pro-
jection of anterior ear of right valve; ears sculptured
by weak to moderate radial riblets (al>out nine when
developed all over the ear), which may be weakly
beaded or nearly smooth; anterior ear of left valve
tends to develop a marginal fold, and terminal edge of
ear indented opposite the fold — the stronger the fold
the deeper the indentation. Both valves normally
have about 30 to 31 radial ribs, but some variants have
no more than 26-28. Ribs of right valve moderately
narrow and straight sided to slightly undercut, and
top flattened, occasionally with a well-defined bifur-
cation of at least one rib; central ribs smooth; terminal
ribs often with weak side denticles, especially on ter-
minal sides. Ribs of left valve subrounded in juveniles
but become flattened or have a median trough on top
in adults, the sides developing well-defined denticles.
Juvenile stage of left valve has raised concentric growth
lines which continue in adults in interspaces and in
concavity on top of ribs. Adult left-valve sculpture
consists of frills or flanges on the ribs, most common
condition being a division of frills into two rows, one
on each side of the ribs; frills vary in size and in dis-
tance from each other; a less common variant has
single frills completely crossing each rib, or the same
specimen may have some ribs with single frills and
some ribs with divided frills; a single specimen from
the Foul Creek formation compared with this species
has no frills, the raised concentric growth lines extend-
ing all the way to ventral margin. Interspaces rarely
have an interstitial riblet, but one specimen, which
has a good development of undivided flanges on main
ribs, has frilled interstitial riblets in some interspaces.
Right valves do not appear to have a raised concen-
tric microsculpture.

Holotype (UC 30381) measures; diameter alxmt 75
mm, height about 79 mm. One of the largest speci-
mens (USNM 563590) with both dimensions complete
measures 123 mm in diameter and 123 mm in height.

The typical form of this species is known only from
the Yakataga formation and in an interval extending
300 to 3,700 feet above the base of the formation, al-
though a possible variant of it was found in the upper-
most part of the Foul Creek formation. The type (a
poor specimen not refigured here) probably came from
about 350 to 400 feet above the base of the formation.
The typical form lias a left valve similar to those fig-

ured on plate 37, figures 4 and 7, and plate 42, figure
3. It was characterized by a juvenile stage having
fine concentric growth lines on the ribs and an adult
stage having well-developed marginal flanges on the
ribs separated by a median trough — the trough is
sculptered by raised growth lines like those on the
juvenile ril». The rihs tend to be less raised and not
as well defined in the advanced growth stages of large
specimens. No specimens seen thus far from well up
in the Yakataga formation have ribs with single flanges
crossing them like the juvenile ribs of P. (/,.) poul-
creekensis, or the possible narrow ribbed subspecies of
it illustrated on plate 38, figure 5.

Palinopecten ( Lituyapecten ) yakatayensi s differs from
P. (/„.) poulcreekensis by having more ribs; about 28 to
31 as opposed to 22 well-defined ribs and 1 or 2
additional fine terminal radial riblets on poulcreekensis.
The ribs of poulcreekensis are larger and broader. The
lateral frills on the ribs of yakaiayensis are separated
from the time of their first appearance, whereas poul-
creekensis has a long post juvenile stage in which the
frills are continuous across the ribs, and on some ribs
they remain single. Furthermore, no specimens of
yakaiayensis have been observed in which the lateral
frills divide again, whereas in poulcreekensis the frills
on some of the ribs may divide secondarily to form four
rows of frills.

The two species differ strikingly in the development
of interstitial ribs; they are strong in poulcreekensis but
very rare in yakaiayensis. (See pi. 42, fig. 3.) There
may be an incipient tendency towards the development
of interstitial ribs on the right valve of yakaiayensis
(see pi. 37, fig. 2), but flanged interstitial ribs are always
present on adults of poulcreekensis, and they are often
as high as the primary ribs (see pi. 35, fig. 5).

In the tentative subspecies of poulcreekensis (pi. 38,
fig. 5) weakly flanged interstitial ribs are present in
some of the interspaces, but more interspaces are with-
out them. In typical poulcreekensis only one or two
interspaces at the terminal ends are apt to lack inter-
stitial ribs.

The ears of yakaiayensis are lower and longer than
on poulcreekensis; the radial markings are finer; the
suprabyssal extension of the anterior ear of the right
valve is narrower ami longer; and the anterior ear of
the left valve tends to develop a submarginal roll or
fold, a condition not apparent on any specimens of
poulcreekensis seen. A fold is well developed in coosen-
sis Shumard. (See Trumbull, 1958, pi. 117, fig. 4.)

Palinopecten ( Lituyapecten ) yakaiayensis was prob-
ably the direct ancestor of P. (/,.) lituyaensis, the species
next described. The latter species occurs in beds be-
lieved to be equivalent to an upper part of the Yaka-
taga formation, but so far no representatives of Litu-

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LITUYAPECTF.N, NEW SUBGENUS, FROM ALASKA AND CALIFORNIA

231

yapecten are known from the highest part of t ho Yaka-
taga formation. The beds containing Lituyapecten in
the Lituya Bay area are believed to be late Miocene or
early Pliocene in age. The subgenus is represented by
still another species in beds of late Pliocene cage in
California. Unless the pattern of distribution known
at present is merely an accident of collecting, the sub-
genus seems to have migrated from the northern Gulf
of Alaska region in the early Miocene to California in
the late Pliocene where it became extinct.

An incomplete right valve from the lower part of
the sandstone-siltstone unit in the Lituya Bay district
(pi. 41, fig. 2) may be P. ( L .) yakatagensis or, at least,
intermediate between P. (L.) yakatagensis and P. (/,).
lituyaensis. It occurs lower in the section than typical
lituyaensis although its position may be stratigraphi-
cally higher than the highest known occurrence of
yakatagensis in the Yakataga formation. The ribs arc
narrower than on lituyaensis. There are 26 ribs; just
under the minimum observed on yakatagensis in the
Yakataga district and just over the maximum observed
for lituyaensis from higher in the section in the Lituya
Bay district.

Distribution . — Early to Middle Miocene, northern Gulf of
Alaska region: Yakataga formation, Yakataga district, Alaska,
possibly in the lower part of the sandstone-siltstone unit in the
Lituya Bay district, Alaska.

Type locality . — Yakataga formation, about 350 feet above the
base of the formation, Yakataga Reef, UC loc. 3859.

Other occurrences . — Yakataga formation, USGS Iocs. 6693,
6695, 15425, 15437(7), 17813, 17840, 17841, 17852, 17853, D256
(T); CAS Iocs. 29230, 29244, 29248, 29251, 29256, 29257, 29270,
29274, 29276, 29277, 29283, 29294; UC loc. 3858.

Doubtful identifications. — Sandstone-siltstone unit, I.ituva Bay
district, USGS D187 (T).

Patinopecten (Lituyapecten) cf. P. (L.) yakatagensis (Clark)

Plate 45, figure 3; plate 46, figure 5

The Miller collection from the upper 50 feet of the
Poul Creek formation at Yakataga Reef (USGS 17733),
Alaska, contains one specimen that is obviously dif-
ferent from other specimens from that interval, all of
which appear to be referable to poulcreekensis. The
unique specimen is more like yakatagensis although it
is not typical. The significance of this specimen was
not recognized in the field and it was not segregated,
but an attempt to determine its stratigraphic position
from the matrix adhering to it and Miller’s very care-
fully described section suggests that it came from a bed
stratigraphically higher than the bed containing abun-
dant individuals of poulcreekensis.

This specimen has only about 24 ribs as opposed to
30 or 31 in the typical form. The ribs on its left valve

have no flanges only a weak sulcus on 1 or 2 ribs.

The raised concentric microsculpture, which normally

characterizes the juvenile stage, extends on this speci-
men all the way to the ventral margin. The specimen
has a maximum height of aliout 90 mm; the transition
from the juvenile to the adult sculpture on both poul-
creekensis and yakatagensis is usually between 30 and
50 mm from the beak.

This form is the probable ancestor of typical yakata-
gensis, and since it occurs at so nearly the same strati-
graphic position as poulcreekensis, and yet differs so
much from it, the suggestion is strong that poulcreeken-
sis is not the direct ancestor of yakatagensis. This
problem is further discussed on page 232-233.

It is also possible that this form from the uppermost
part of the Poul Creek formation may be ancestral to
other late Tertiary pectinids besides P. (L.) yakatagen-
sis; lineages which did not continue to live in the im-
mediate area. One such possible descendent is Pati-
nopecten coosensis (Shumard) from the Empire forma-
tion (Pliocene?) of Oregon which does not seem to he
very closely related to the Miocene to Recent P. pro-
patulus — P. caurinus stock, but which could very well
have come from P. ( L .) cf. yakatagensis from the. Poul
Creek.

Locality . — From the upppr 50 feet of the Pool Creek formation
ut Yakataga Reef, Alaska, presumably from above the zone of
P. (L.) poulcreekensis, USGS 17733.

Patinopecten (Lituyapecten) lituyaensis MacNeil, n. sp.

Plate 39, figures 1, 3; plate 40, figures 1-5; plate 41, figure 1;
plate 42, figures 1, 2, 4; plate 43, figures 1-4

Shell large, asymmetrical; posterior extension greater
than anterior extension, and greatest height posterior of
median line; right valve more inflated than left valve;
shell of medium thickness. Dorsal margins concave in
region of ears, but become nearly straight dis tally;
dorsal margins low; left valve may have a low steplike
marginal slope, particularly along left side; left valve
ears inflated and lie higher than adjacent disk; byssal
fold may be greatly swollen. Dorsal margin of earn
straight centrally but curves vent rally towards distal
end; anterior ear of right valve curves strongly in large
specimens. Earn of moderate size for a large shell; no
denticles along margin; byssal sinus moderately deep;
ears sculptured by scabrous or beaded radial riblets
which tend to die out distallv and which may be very
weak or absent on some specimens; a weak dorsal fold
and a corresponding terminal indentation on anterior
ear of left valves. Both valves with about 23 or 24
broad radial ribs. Ribs of right valve higher centrally
and low to nearly flush terminally; central ribs smooth
and rounded on top; terminal ribs have weak luteral
frills and concave tops; interspaces smooth or have
frilled interstitial ribs in one or more of terminal inter-
spaces. Left valvo has frilled ribs, which may be single

47*101 O -41 -2

232

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

and narrow terminally but broad centrally with a raised
row of strong but narrow beadlike frills on each side,
or more rarely with a middle row of frills ns well; inter-
spaces wider than ribs in adults but narrower than ribs
in juveniles, sometimes with beaded or frilled inter-
stitial riblets in one or two interspaces. Juvenile
sculpture of left valve consists of raised concentric
growth lines which are slightly convex towards beak
and which are not raised on bottoms of interspaces, but
which are raised in median trough on ribs for some dis-
tance beyond first appearance of marginal frills. Mi-
crosculpture of adults consists of growth lines convex
towards margin in interspaces and concave towards
margins on ribs but not raised as in juveniles. Right
valve microsculpture consists of faint radial markings
but otherwise smooth.

Holotype, a right valve (USNM 563598), measures:
diameter 210 mm, height 220 mm. The left valve
paratvpe is numbered USNM 563599.

The holotype of this species is one of the largest
Tertiary pectinids known — if a larger specimen has
ever been reported— and fragments of other speci-
mens indicate that an even larger size was attained;
possibly ns much as 250 mm. It may have the dis-
tinction also of being the first pectinid observed in
the rocks of western North America, the “manteau
royal” mentioned in the narrative of La P6rouse’s
expedition of 1786.

This species is descended probably directly’ from
P. (L.) yakatagensis. It is larger and asymmetrical,
whereas yakatagensis is nearly round. Most of the
known specimens appear to be deformed by rock
flowagc in one way or another; some are shortened,
some lengthened, and others arc flattened. It has
fewer and broader ribs than yakatagensis. The ears
are larger and higher, and the byssal notch and the
byssal fasciole are not as broad. The terminal ribs
on the right valve of yakatagensis usually’ have a row
of weak frills on the outer side, but the terminal ribs
of lituyaensis usually have frills on both sides, and
the ribs tend to be broader with a concave top. How-
ever, there is considerable variation in this respect;
compare figure 1 of plate 40 with the corresponding
area on figure 3.

The terminal ribs of the left valve of both species
tend to be narrow and to have only a single set of beads
or flanges; this feature differs from specimen to speci-
men, and opposite ends of the same specimen may’ be
unlike. The left valve of lituyaensis sometimes has
a strong third beaded riblet on some of the middle
ribs (pi. 43, fig. 1), possibly a function of its wider ribs.
Only one specimen of yakatagensis seen (pi. 42, fig. 3)
has any indication of a third row of beads, and on it

the third row is very weak. It is interesting to note
that this specimen also has a fine beaded interstitial
riblet, a variation which in lityuaensis accompanies
the presence of the third beaded riblet on the ribs.
Patinopecten ( L .) lituyaensis has its flangelike beads
in well-separated rows, the variation being from well
to widely separated ; in yakatagensis t he rows range from
narrowly to well separated, the maximum separation in
yakatagensis being about the minimum separation
in lituyaensis. The minimum separation in yakata-
gensis is about equal to the maximum separation in
poulcreekensis, the latter species ranges to specimens
having no division of the flanges.

The frilled interstitial ribs seen on several right
valves of this species (pi. 39, fig. 3; pi. 40, figs. 2, 5)
seem to be a common occurrence, and they resemble
to a lesser degree the interstitial ribs of P. (L.) poul-
creekensis. Similar ribs have not been observed in
yakatagensis.

The microsculpture on juvenile left valves of lituyaen-
sis (pi. 42, fig. 2) is similar to that of yakatagensis
(pi. 37, figs. 3, 5). On both species the transition to
the adult stage with side frills on the ribs is less abrupt
than on poulcreekensis (pi. 36, fig. 6).

All three species are in contrast to a specimen,
identified as P. (L.) cf. yakategensis, collected by
Miller (pi. 45, fig. 3; pi. 46, fig. 5) from above the
P. (T.) poulcreekensis zone but still below the base of
the Yakataga formation (included in USGS 17733).

This single and only known unfrilled specimen from
the upper part of the Poul Creek formation poses a
problem regarding the ancestry of both yakatagensis
and lituyaensis. There seems to be little doubt that
lituyaensis is descended directly from yakatagensis.
However, in some respects the unfrilled Poul Creek
form appears to be a more likely ancestor of typical
yakatagensis than pottlcreekensis does; poulcreekensis,
although related, may belong to a different lineage
that is more closely related to P. dilleri. The strongest
resemblance between yakatagensis and poulcreekensis
lies in the possession by r both of divided flanges. The
flanges of poulcreekensis arc more exaggerated and
have a greater range of variation than those of yakata-
gensis, its possible successor. On the other hand, the
unfrilled Poul Creek form is what might be expected
for the ancestor of yakatagensis. It. has narrow ribs
although they are fewer than in typical yakatagensis.
The beaks and ears are similar, even to the fold along
the dorsal margin of the anterior ear of the left valve,
a condition also strongly developed in P. coosensis.
(See Arnold, 1906, pi. 6, fig. 2.) The fact that the
Poul Creek form does not have frills on its ribs may be
outweighted by the fact that on some specimens of

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LITUYAPECTEN, NEW SUBGENUS, FROM ALASKA AND CALIFORNIA

233

typical yakatagen&is they are very weak and by the
fact that the adult sculpture of the Poul Creek form is
like the juvenile sculpture of yakatagemis.

It may be unsafe to draw conclusions on the few
specimens known at present. It is possible, however,
that poulcreekensis and the unfrilled form, here indenti-
fied as P. {L.) cf. yakatagemis, represent already
divergent stocks of common ancestry and that poul-
c re e ken sis may be the ancestral stock of dilleri, whereas
the unfrilled form may be the ancestral stock of the,
typical yakatagemis ami lituyaensis, as well as of
coosensis.

The next younger members of this group of pectinids
are from the Pliocene of California; after lituyaensis
none are known from Alaska.

Distribution. — Late Miocenef?) and (or) early Plio-
cene, Lituya Bay district, Alaska: Occurs in both the
lower sandstone-siltstone unit and the upper mud-
stone unit.

Type locality . — Upper mudstone unit of unnamed upper
Tertiary formation, about 300 to 310 feet above the base of the
upper mudstone unit, southwest shore of Cenotaph Island,
I.ituya Bay, Alaska, USGS M270.

Other occurrences . — Lower sandstone(?)-siltstone unit, USGS
D223 (T), D264 (T): upper mudstone unit, USGS 1)174 (T),
M270.

Patinopecten (Lituyapecten) purisimaensis (Arnold)

Plate 44, figures 1, 3

Pectcn ( Patinopecten ) purisimaensis Arnold, 1906, U.S. Geol.

Survey Prof. Paper 47, p. 105, pi. 34, fig. 3, pi. 35, figs. 1, la.

Grant and Gale, 1931 (in part), San Diego Soc. Nat.

History Mem., v. 1, p. 194, pi. 0, fig. 3.

The type of this species, deposited at Stanford L T ni-
versity (SIT 3), is a very poor specimen; and although
a better right valve was figured by Grant and Gale, it
has remained inadequately illustrated. The specimen
figured here, although incomplete and partly riddled by
borings, is by far the best specimen of the species I
have seen and illustrates most, of its characters very
well.

The typical form of the species has rather narrow
ribs on its right valve, and most of the ribs have short
marginal denticles or flares recalling those on the termi-
nal ribs of P. (L.) lituyaensis. (See pi. 41, fig. 1.) The
left valve has narrow ribs with wide, round-l>ottomcd
interspaces. Two or three of the central ribs are
slightly wider with a weak concavity along the crest,
but most of the ribs are narrowly rounded on top and
bear a single row of denticles or narrow flanges along
their crest.. They are broken or worn on most, speci-
mens observed, and even on the fairly well preserved
specimen figured here, only their base is preserved.

Patinopecten turneri Arnold from the Pliocene of the
Tomales Bay region, California, was regarded by Grant
and Gale (1931, p. 194) as a synonym of purisimaensis.
If Grant and Gale were influenced bv an error in
Arnold’s statements almut his figured specimens they
did not say so. Arnold figured three specimens, two
of them as right valves and one as a left valve; however,
all three of Arnold's specimens are left valves. This
gave him an erroneous concept of his supposed new
species and made it appear to lie very different from
purisimaensis. Actually purisimaensis and turneri
are closely related, but some good specimens of turneri
collected by Dr. Joseph H. Peck of the University of
California show a well-defined sulcus on the right valve
ribs that is not found in purisimaensis. These species
should probably be kept separate.

Patinopecten (/,.) purisimaensis is related to P.
(I..) dilleri (Dali), a species common in the Pliocene of
southern California but deeribed from the Pliocene of
Humboldt County, northern California. P. (L.) dilleri
usually has coarse flanges on both valves, those of the
right valve being either single and crossing the ribs
(Arnold, 1906, pi. 5, fig. 2), or divided ami along the
margins of the ribs (Woodring and Bramlette, 1950,
pi. 11, fig. 1). The left valve has strong single flanges
(Woodring and Bramlette, 1950, pi. 11, fig. 9). It is
doubtful if dilleri should be regarded as a variety of
coosensis as was done by Grant and Gale (1931, p. 193).
In view of the Alaskan forms now known, it seems more
likely that dilleri and coosensis stem from different early
Miocene forms; dilleri from poulcreekensis, and
coosensis from an early variant of yakalagensis.

In spite of its apparent close relation to dilleri,
purisimaensis appears to be more closely related to
falorensis, a species here described from the Falor
formation (Manning and Ogle, 1950) of northern
Humboldt County, Calif., n formation equivalent to
a part of the Wildcat series of Lawson (1894). In
fact, it is difficult to say from the known specimens
whether two species are represented in the Purisima
formation, purisimaensis and falorensis, or whether
all the specimens in question should be regarded as
belonging to one greatly variable species. For the
time being they are treated as two species although
it may later be found preferable to treat falorensis as
a subspecies of purisimaensis.

Distribution. — Pliocene, central California: Purisima forma-
tion, San Mateo County, Calif.

Type locality . — North of the mouth of Pescadero Creek,
San Mateo County, Calif., SU 3.

Other occurrences. — l.'C 4417, SU 4922.

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234

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

P&tinopecten (Lituyapecten) falorensis MacNeil, n. sp.

Plate 38, figures 1, 3; plate 44, figures 2, 4; plate 45, figures
2, 4; plate 46, figures 1-4

Pecten oregonensis Howe var. Manning and Ogle, 1950, Calif.

Div. Mines Bull. 148, p. 23-24, pis. 6, 7.

Shell moderately large; suborbicnlar to weakly
extended posteriorly; valves moderately inflated; right
valve slightly more inflated than left valve; shell
moderately thin. Posterior dorsal margin moderately
eonoave, and anterior margin nearly’ straight; left
valve with low hut sharp steplike suhmarginal slopes,
and right valve slopes less sharp because of inflation
of ears. Dorsal margin of ears straight. Kars sculp-
tured by radial riblets with moderately strong beads,
about seven riblets on posterior ear of left valve;
posterior ears longer and with stronger radial riblets
than anterior ears; no denticles along byssal sinus;
dorsal margin of left car of left valve with a weak
swelling or fold. Ribs 21 to 23. Right valve often
having a split rib, one segment having no counterpart
on left- valve; right, valve ribs broad with undercut
sides, interspaces narrow and deep; bottoms flattened;
central ribs flattened or rounded on top; terminal
ribs with a median sulcus which at the margin may
be nearly as deep and wide as the primary interspaces.
Left valve ribs moderately' broad with a row of short
flanges or denticles along each side; central area de-
pressed and troughlike; three terminal ribs on each
side narrow and with a single row of short flanges
on their crest; interspaces round-bottomed and nar-
rower than the ril>s on some specimens, wider on
others; no interstitial riblets on any 7 specimens observed.
Juvenile microsculpture unknown.

Holotvpe, both valves together (right valve, UC
34172, left valve UC 34171) measures; diameter 107
mm, height 99 mm. Figured specimen UC 15977
has a height of 130 mm.

The specimen figured by Manning and Ogle, re-
figured here and made the holotypc of the species,
is the only r specimen of a yakatayensisAiko Lituya-
pecten figured previously other than the type of yaka-
tayensis itself. Its relationship to yakatayensis was
not recognized and instead, it was identified tenta-
tively 7 as a variety 7 of P. oreyonensis Howe, a species
described from the Empire formation of western
Oregon. Possibly 7 the association of this species with
oreyotunsis came about because of the incorrect lo-
cality data given by 7 Howe for a specimen he figured.
This specimen (Howe 1922, pi. 11, fig. 2) was stated
by Howe to be from the Wildcat series of Humboldt
County, C'alif. ; but according to its number (X. P. 82
of the Arnold catalog; not 28 as stated by Howe),
it comes from north of the mouth of the Raft River,

Taholah, Grays Harbor County, Wash., a locality
of indefinite formational assignment. There might
have been some question, had the specimen figured
by Howe actually 7 come from the Wildcat series, as
to whether it was oreyonensis or falorensis , because
it is very difficult to identify right valves, even on
specimens whose left valves are very 7 dissimilar. How-
ever, its correct locality together with the fact that
it compares favorably 7 with other right valves of
oreyonensis makes it safe to assume that it belongs
to that species.

There are two specimens in the Manning and Ogle
collection besides the holotypc. They are smaller than
the type, but they appear to have narrower ril>s than
the corresponding stage on the type. In this respect
they approach some of the typical specimens of P. j>uri-
simaensis. The left valves of these two specimens have
narrow but definitely flat-topped ribs with denticulate,
margins like the specimen from the Purisima formation
illustrated on plate 45, figure 2, here referred to P. (L.)
falorensis. Typical P. (/>.) purisimaensis, on the other
hand, has narrow rounded ribs over most of its disk
with two or three of the central ribs slightly 7 wider and
having a weak concavity along the crest. (See pi. 44,
figs. 1 , 3.) The Purisima formation hIso contains a
form that has wide ribs on the right valve and broad,
flat-topped ribs with marginal denticles on the left
valve (pi. 44, figs 2, 4), and that compares favorably
with the type of falorensis.

Although it is difficult, to say how many species are
involved here and, if they are distinct, just what the
varietal range of each species is, it is fairly certain that
purisimaensis and falorensis are very closely related.
P. ( L .) yakatayensis is a highly variable species if all
the specimens here referred to it are really conspecific.
The same range of variation has not been noted in
lituyaensis, but possibly all variants of that species have
not been found. If approximately the. same range of
variation could be demonstrated for lituyaensis, a strong
cast- for considering Jalorensis as a variety or, at most,
a subspecies of purisimaensis could be made. To state
the problem another way, it is not known whether
purisimaensis and Jalorensis represent divergent stocks
of common but not too distant ancestry or whether the
three species, yakatayensis, lituyaensis, and purisimaen-
sis (including/a/orca.vis) are linear elements of one very
variable stock, no parts of it having been clearly set off
by geographical isolation. If the latter were so, all
the variants existing at any particular instant of time
belonged to one species, whereas the mean of variation
shifted sufficiently through time to make at least three
distinct species recognizable.

The Stanford University collection contains another
specimen from the Purisima formation (pi. 45, fig. 4;

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LITUTAPECTEN, NEW SUBGENUS, FROM ALASKA AND CALIFORNIA

235

pi. 46, fig. 1) that has wide ribs on the left valve like
those of typical falorensix. However, the right valve
has high, comparatively narrow ribs that approach
those of typical purisimaensis. Furthermore, some of
the interspaces on the right valve have strong inter-
stitial ribs, almost as strong as those of P. ( L .) poul-
creekensis. On the basis of its left valve, and because
some individuals of falorensis have narrower ribs than
tile type, I am identifying this specimen as faloremix.
A similar specimen, except that it lacks interstitial ribs,
is in the University of California collection (UC 32659).

Distribution. — Pliocene, northern and central California: Falor
formation of Manning and Ogle, 1950, northern Humboldt
County; Rio Dell formation of Ogle, 1953 (Wildcat aeries of
Lawson, 1894), Humboldt County; Purisima formation, San
Mateo County, Calif.

Type locality. — Falor formation, near bridge crossing Boulder
Creek, adjacent to the Wiggins Rach, about 10 miles southeast
of Blue Lake, Humboldt County, Calif., UC A4233.

Other occurrences. — Falor formation, SU 4837; Rio Dell for-
mation, SU 4932, SU 4937; Purisima formation, UC 1780 (32659),
UC 1788, UC A4343, SU 1095, SU 29788.

Patinopecten (Lituyapecten) cf. P. (I.) dilleri (Dali)

Plate 41, figures 4, 5; plate 45, figure 1

The following is a partial synonymy for typical P.
( L .) dilleri :

Pcclen ( Lyropecten ) dilleri Dali, 1901, Nautilus, v. 16, no. 10,
p. 117.

Pecten ( Patinopecten ) dilleri. Arnold, 1906, U.S. Geol. Survey
Prof. Paper 47, p. 62, pi. 5, fig. 2.

Jordan and Herllcin, 1926, California Acad. Sci. Proc.,
v. 15, no. 14, p. 431, pi. 30, fig. 1.

Pecten ( Patinopecten ) coosensis Shumard variety dilleri Dali.
Grant and Gale, 1931, San Diego Soc. Nat. History, Mem.
1, p. 193.

Patinopecten dilleri. Woodring in Woodring and Bramleltc,
1951, U.S. Geol. Survey Prof. Paper 222, p. 84, pi. 11,
figs. 1, 9 [imprint date 19501.

Fragments of a large Patinopecten which may rep-
resent a new species were collected from a horizon
high in the Lituva Bay section. One large fragment
of a left valve and two small fragments of a l ight valve
are represented. The left valve (pi. 45, fig. 1) has
moderately broad rounded ribs with irregular flanges
crossing them and broader, round-bottomed inter-
spaces; at least one of the interspaces has a weak inter-
stitial riblet bearing fine flanges. The right, valve (pi. 41 ,
figs. 4, 5) has broad, slightly undercut ribs and narrower
deep interspaces. The fragments appenr to be from
the central part of the disk. No denticles or flanges
are present on the right valve fragments although
terminal ribs might have them.

The right- and left-valve fragments figured here
are believed to be the same species, if not the same
individual, but there is no assurance that this is so.

If they are, the Alaskan form has much broader ribs
on its right valve than does typical dilleri from Cali-
fornia; the right valve also lacks the spiny lamellae
commonly present on the southern form. (Sec Wood-
ring, 1950, pi. 11, fig. 1.)

A nearly perfect specimen of dilleri with both valves
together was collected by E. H. Quale in the city of
San Diego. It is in the collection of the University of
California at Ix>s Angeles, (UCLA 8072, plesiotype
No. 309) and is to be figured in a forthcoming paper
on the fauna of the San Diego formation bv L. G. Hert-
lein. The left valve of this specimen has the typical
single-flanged ribs of the species, but the right valve
has nearly smooth, moderately narrow ribs. Probably
this specimen and the specimen figured by Woodring
(1950, pi. 11, fig. 1) with strong lateral lamellae on
the right valve ribs can be taken as nearly opposite
extremes in right-valve ornamentation.

The left valve from Lituya Bay appears to be more
like a specimen of dilleri, figured by Jordan and Hert-
lein (1926), from Pliocene beds near Elephant Mesa
in the Scaminon Lagoon quadrangle, Ixnver Cali-
fornia, than any figured from farther north. The
Lower California specimen has elongate flanges which
are single on most ribs; on some ribs the flanges break
up into two series with the opposite elements alternat-
ing, a condition found on some of the ribs of P. (L.)
poulcreekemi 8 . (See pi. 35, fig. 6, and pi. 36, fig. 4.)
Usually, as on the specimen figured by Woodring (1950,
pi. 11, fig. 9), the flanges on the left-valve ribs are
shorter and more regular.

Of several good specimens, including the holotypc,
from the Wildcat series of Lawson (1894), all but one
show only, or consists of only, the right valve. One
lot from the Tomkins Hill Gas Field, Humboldt
County (CAS 34391), consists of a rubber cast of a
large, nearly perfect right valve (presumably made in
the field) and shells of two incomplete left valves.
The left valves appear to be very similar to the speci-
men figured from Elephant Mesa, Lower California.

There seems to be little doubt that dilleri is a Lituya-
pecten. It is a highly variable species if all the speci-
mens that have been referred to it are really conspecific.
Among pectens of its own age, it appears to be most
closely related to P. (L.) puriximaenxix as numerous
writers have claimed. However, it lias characters
which link it unmistakably with both P. (A.) poul-
creekensi * and poulcreekensus var. (pi. 38, fig. 5), both,
early Miocene forms. Its relation to puriximaenxis
may be, therefore, one of parallcllism rather than of
direct intergradation, purisimaensis merely repre-
senting the varietal extreme of the puriximaensis-
jalorenxis stock that perpetuated more of the characters

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236

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

that boih it and the dilleri stork inherited from a
common early Miocene ancestor.

Woodring (1950, pi. 9, figs. 6-8) figured three left
valves from the Sisquoc formation of the Santa Maria
district, California, ns ,l Patinopecten dilleri variety."
This form has well-developed interstitial riblets, con-
centric frills which completely bridge the interspaces
between the ribs (crossing the interstitial ribs in so
doing), and a well-developed imbricating microsculp-
ture resembling the surface of metal lath. I have not
seen any of these characters on other members of the
dilleri. group. In spite of its excellent preservation,
this is a very puzzling shell. It will be. interesting to
see what its right valve looks like, if and when one is
found. Dr. Ia*o G. Hertlein, of the California Acad-
emy of Sciences, who has had a long and special inter-
est in west-coast pectinids, tells me that he does not
believe it is a Patinopecten and that he knows of no
other west-coast species like it. It could be the left
valve of the species described by Arnold (1906, p. 117,
pi. 45, figs. 3, 4) as Pecten ( Chlamys ) lamoni. Arnold
figured two fragments, one as a left valve and one as a
right valve; both of them may be right valves. Grant
and Gale (1931, p. 166) and Woodring (1950, p. 83)
tentatively put lawsoni in the synonymy of Chlamys
hasiatus (Sowerby). Unfortunately, the typos of la v>-
soni were lost in the San Francisco fire of 1906.

Distribution. — The Alaskan specimens identified as Patino-
pecten ( Lituyapecten ) cf. P. (L.) dilleri are from the upper mud-
stone unit of an unnamed Tertiary formation, Lituva district,
Alaska, USGS 7931.

The following is the known distribution for typical P. (L.)
dilleri: Lower California and California. Pliocene l>eds near
Elephant Mesa, Scatnmon Lagoon quadrangle. Lower Califor-
nia, Mexico; San Diego Calif.; Puente Hills and Newport Beach
Los Angeles basin, California; Hills north of Simi Valley, Ven-
tura County, Calif.; Foxen mudstone, and Cebada fine-grained
member of the Careaga sandstone, Santa Maria district, Cali-
fornia; Rio Dell formation of Ogle, 1953 (Wildcat series of Law-
son, 1891), Eel River basin, Humboldt County, Calif.

Type locality. — Bluffs opposite Rio Dell, Eel River, Hum-
boldt County, Calif., (USNM 164846) USGS locality 3363.

Other occurrences. — Lower California: SU 4936 (CAS 2095);
San Diego, UCLA 8072; Puente Hills, Pomona College collec-
tion; Newport Beach (fide J. G. Vedder); Santa Susans, SU
1828; Simi Valley, UCLA collection; Santa Maria district.,
USNM 5C.0053, USGS 14619, SU 1912; Eel River, SU 4821,
CAS 117; Tomkins Hill Gas Field, CAS 34391.

Patinopecten (Patinopecten) caurinus (Gould)

Pecten caurinus Gould, 1850, Boston Soc. Nat. History Proc.,
v. 3, p. 345.

Pecten (Patinopecten) caurinus. Dali, 1898, Wagner Free Inst.
Sei. Trans., v. 3, p. 710.

Pecten { Chlamys ) caurinus. Oldroyd, 1921, Stanford Univ.
Pub. Gcol., v. 1, p. 57, pi. 0, fig. 1, pi. 4, fig. 1.

Pecten ( Patinopecten ) caurinus. Grant and Gale, 1931 [in part),
San Diego Soc. Nat. History Mem. 1, p. 194. pi. 6, fig. 4.
(See for extended bibliography.)

Grant and Gale discuss this species at length and
cite a long bibliography. Not all of their synonomy
is correct, however; certainly projtahtlus Conrad and
oregonenris Howe, although related, do not belong to
this species.

This species, the type of Patinopecten, is here regarded as
being subgenerically distinct from the other species treated in
this paper. No attempt is made to list all the fossil occur-
rences. It is included for the purpose of recording its occur-
rence at two localities in the upper part of the Yakataga forma-
tion, one in the Yakataga district and one in the Malaspina
district. It occurs well above the highest occurrence of P. (L.)
yakatayensis. If the present inferred correlation is correct, its
earliest occurrence in the Yakataga district falls within the age
range of P. ( L .) lituyoensis in the Lituya district. The speci-
mens are not well preserved and arc not figured.

Localities . — Yakataga formation, CAS 29280, USGS D263
(T), D336 (T).

Vertipecten sp. indet.

Another pectin id, possibly a Vertipecten, which so
far is known only from fragments and internal molds,
occurs in the Yakataga formation at about the same
stratigraphic position as P. (L.) yakatagensis. This
form has a long anterior ear on its right valve, narrower
and more numerous ribs, and moderately high dorsal
slopes. It may be related to V. portereims (Weaver).
It is still too poorly known to be described.

Patinopecten ( Lituyapecten ) poulcreekemis has a
superficial resemblance to some species of Vertipecten,
and it occurs in beds of the same approximate age.
Both have rather smooth ribs on the right valve and
scabrous ribs on the left valve. However, although
the ribs of the left valve of Vertipecten have large frills,
the frills do not show any tendency to become divided
into two well-defined rows, the common condition in
adults of Lituyapecten. The right valve of Vertipecten
has a rather steep umbonal slope. The left valve has
a strong imbricating microsculpture, and there is a
tendency for the ribs to be unequal. In some species
[V. neradanus (Conrad)], there is a tendency for every
fourth rib to be stronger, whereas in others [V. fucamts
(I)all)] one central rib may be stronger than the others.
Left valves of Vertipecten are more inflated than right
valves.

Occurrence . — The stratigraphic occurrence of this supposed
Vertipecten is indicated by an asterisk in figure 46; CAS 29246,
29253, 29287, 29290. Another float specimen, presumably from
the lower part of the Yakataga formation, is numbered USGS
17797.

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LITUTAPECTEN, NEW SUBGENUS, FROM ALASKA AND CALIFORNIA

237

REFERENCES

Arnold, Ralph, 1906, Tertiary and Quaternary Pectens of
California: U.S. Geol. Survey Prof. Paper 47, 2G4 p., 53 pis.

Clark, B. L., 1932, Fauna of the Poul and Yakataga formations
(upper Oligoccne) of southern Alaska: Geol. Soc. America
Bull. 43, p. 797-846, pis. 14-21, 1 fig.

Dali, W. H., 1901, A new Lyropecltn: Nautilus, v. 14, p. 117-118.

Grant, U. S., IV, and Gale, H. R., 1931, Catalogue of the marine
Pliocene and Pleistocene mollusoa of California and adjacent
regions: San Diego Soc. Nat. History Mem., v. 1, 1036 p.,
32 pis.

Ilatai, K. M., 1938, A note on Prclen kngaminnus Yokoyama:
Japan Biogeographical Soc. Bull., v. 8, no. 6, p. 103-110.

Howe, H. V., 1922, Faunal and stratigraphic relationships of the
Empire formation, Coos Bay, Oregon: California Univ.
Pubs, in Geol. Sci., v. 14, no. 3, p. 85-114, pis. 7-12.

Jordon, K. K., and Hertlein, L. G., 1926, Contribution to the
Geology and Paleontology of the Tertian’ of Cedros Island
and adjacent parts of Lower California: California Acad.
Sci. Proc., 4th scr., v. 15, no. 14, p. 409-464, pis. 27-34.

La Pfrouse, J. F. de G., 1797, Voyage de La Ptirouse autour du
monde, public conform£ment an d^cret du 22 avril 1791,
et r<5dig6 par M. L. A. Milet-Mureau: Paris, Imprimerie de
la Rt^publique, v. 2, 398 p.

Lawson, A. C., 1894, The geomorphogeny of the coast of northern
California: California Univ. Pubs., Dept. Geol. Bull., v. 1,
p. 241-271.

Manning, G. A., and Ogle, B. A., 1950, Geology of the Blue
Lake quadrangle, California: California Div. of Mines,
Bull. 148, 36 p., 11 pis., 3 maps.

Masuda, K., 1953, A new species of Pnlinopteten from Ibaragi
Prefecture: TShoku Univ., Inst. Geology and Paleontology,
Short Papers no. 5, p. 41-50, pis. 5, 6.

1954, F'ossil Pectinidae drom Fukuoka-machi, Ninohe-

gun, Iwate Prefecture: Saito Ho-on Kai Research Bull.,
no. 23, p. 11-14, figs. 1-3.

Ogle, B. A., 1953, Geology of Eel River Valley Area, Humboldt
County, California: California Div. Mines Bull. 164, 128 p.,
14 figs., 5 pis., 1 map.

Trumbull, E. J., 1958, Shumard’s type specimens of Tertiary
mollusks from Oregon and other types formerly at Wash-
ington University, St. Louis: Jour. Paleontology, v. 32,
no. 5, p. 893-906, pis. 115-117.

Woodring, W. P., and Bramlette, M. N., 1950, Geology and
Paleontology of the Santa Maria District, California:
U.S. Geol. Survey Prof. Paper 222, 179 p., 22 pis., 9 figs.,
1 map [1951].

Yabe, H., and Hatai, K. M., 1940, A note on Pecten (Fortipecien,
subg. nov.) takahaahii Yokoyama and ita bearing on the
Neogene deposits of Japan: TChoku Univ. Sci. Repts.,
2d ser. (Geology), v. 21, no. 2, p. 147-160, pis. 34-35.

Yokoyama, M., 1929, Pliocene shells from near Nanao, Noto:
Japan Geol. Survey Rept. 104, p. 1-7, pis. 1-6.

INDEX

(Italic number* Indicate descriptions)

Pane

(Amnstiopeden), PeeUn - 220

A murium 220, 227

Astoria formation... 22S

Barnacles 2235

beringianut, Chlamjt - - - 227

Camptonedet. 226

Carcaga sandstone, Cebada member ... 236

caurlnus, Paiinopeden 220. 227, 231

Paiinopeden {Paiinopeden) - 227, 228. 235

PttUn 225,23*

( Paiinopeden) 23t>

Ceboda member, Carcaga sandstone, fine-grained 230

Cklampt 22&22T

betinyionus 227

(Chl&m ft) 227

hotiatus 230

( S'tifiopeden ) 227

(CAfomjw) lowtoni, Peden 230

Clark, B. L., quoted 2235

cooicr. tit, Paiinopeden 227. 229. 23d 231, 232, 233

Peden ( Paiinopeden) 235

diUeri group 230

Paiinopeden 228,232.233.235

(LUuyapeden) W3.mpb.Aia5

Pedtn ( Lyroptden) 235

( Patino peden) 235

vnr.. Poiinopeden 230

Empire formation

234

Falor formation ,

faterensis, Paiinopeden {Liiupaptden) 225. 233, Wl. 235,

Fortlpeden

Foxen mudstone

fuconus, Vert i peden

233,235

227

236

Qrunt. U. and Gale, XL K., quoted. .

226

hatlaiut, Chlamyt 236

ibarogimru. Paiinopeden 227

jaeobaevt, Paiinopeden (Paiinopeden) 226

Janira 226

K a tails formation.

229

louton », Peden (Cklamjs).

liiufaensit, Paiinopeden (LUuyapeden)

Lit Ufa peden

(Ltiuyapeden) diUeri, Paiinopeden

falor ends. Paiinopeden

Itiuyacnsit, Paiinopeden

I*ol inop e den

diUeri

pooler eekenrit. Paiinopeden

subsp.. Paiinopeden

var.. J'ail no peden

purisimaensit, Poilnopedcn

236

22L 230, ML 234, 230, pb. 39-13

220. 227, 2215, 230, 231. 231. 235. 236

235.236

225, 233, ML 235, pis. 38, 44, 45, A6

... 227, 230, ML 231, 230, pb. 39, 40, _4L 42, 43

227. 228. Wf. 233. 236 Dl. 46

M3. pb. 41, 45.

m, 230, 23L. 232, m 235, 236. pb. 35, 36. 38

fM, 230, pb. 36, 38

235

M5. 234. 235. pi. 44

yakaiafentit, Paiinopeden. . 227, tt9, 230, 231. m 233. 234, 236, pb. 37, 36, 39, 4L42

( Lyropeclen ) diUeri, Peden 235

netodanut, Verlipeden 230

ninohentit, Paiinopeden pamatnkii 22fl

oreyonensit, Paiinopeden 2313

Pail nopeeten —Con tlnued

(LUuyapeden).

diUeri

falor ensis

fi/Myarnm

poulcr etkentit....,

SUbsp

var

purltimaensit. ...

yakaiayensis

o ttgonentlt

(Paiinopeden)

continue

jacobaeus

propat ulus.

puritimaensis

f turner!

Page

227.228, Wf. 233. 236. pi. 46

W5.236. pb 4JL45

225. 233. Mi. 235. pi». ». 44.45

227.Wf. mmpb. 39.40.41.42.43

its, 230. 231 . 232. 233. 235. 236. pb 35,36,38

W9.230. pb. 36.38

235

W3. 234.235. pl. 44

227. ttS. 230. 231. 232. 233. 234. 236. pb. 37, 3$. 39. AL 42
236

.... 227.228.236

226

227.228.231,236
.... 225.234.235
233

pa mars ltd nlnohentls

pestoentit

(Paiinopeden) caurlnus, Paiinopeden

catirinus, Peden.. .................

cooitntis, Peden

dlllert, Peden

jaeoboeus. Paiinopeden

Paiinopeden

puritimaentit. Peden

poiategantit, Peden

Peden (A must opr den)

caurlnus...

(Cilamys) lau'tonl

( Lpropeden ; diUeri

(Paiinopeden) caurlnus . . ..............

coosentit

diUeri

pur iri mar am

pakaia^ansis

(Peden) -

orefonentit

Peden

Place peden

porter entis. Verlipeden

Foul Crwk formation

pooler eekenrit. Paiinopeden ( Lilupapeden )

subop., Paiinopeden (LUuyapeden)

var.. Paiinopeden (LUuyapeden)

proDoiulus. Paiinopeden

Propeamustium.....

Pstudamutrlum

Furisima formation —

puritimaentit, Paiinopeden

Paiinopeden (Lttuya peden)

226,228

226. 227

227.228.236

236

235

226

233

225.228

226,227

225.236

236

235

236

235

233

225.228.229

226

225.234

226,227

226

236

229.230.231.232

fM, 233. 233. 235. 236. ub. 35. 36. 38

M9.230, pb. 30.38

235

227,228.231,236

226

225.233.234.235

225. 23 1. 235

M3. 234.254. pi. 44

Peden (Paiinopeden)

233

RtO Dell formation.

235

Sblmtorl formation

Sbquoc formation

(Stei/fopertrn), Chtamps.

226

236

227

turneri, Itelinopeden

233

Unnamed formation, upper Tertiary

233

Verlipeden —
fucanus...
nevadanu*.
potierensit.
SP

226.227.236

236

Wildcat aeries

233.234.235.236

Peden 225.234

Paiinopeden 225. 226. 227. 228. 220. 235. 236

caurinus 220.227,231

ccosentit... 227.228.230.231.232.233

differ! 228.232,233,235

var 236

ibaroyientis 227

Yakotagu formation —

Yakattga Keef -

yakafayenris. Paiinopeden

Pattnopeden (/Mu pa peden). 227.fW.23U.231,

Peden (/*uf!nopre/ri»)

ya.vuMolit nfnMrnib, Paiinopeden

yettoensis, I'aiinoptden

229.230.231.236

225.229.231

226. 228

232. 233. 234. m pb. 37, AL^2

225. 228

22*

220.227

239

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PLATES 35-46

PLATE 35

[Figs. 1-5 slightly reduced; fi, X 1. All specimens from Poul Creek formation, USGS M271, unless otherwise Indicated)

Fiocbe 1-6. Palinopeclen ( Lituyapcden ) poulcreekengi « MacXeil, n. «p. (p. 228).

1. Ilolotype, a right valve, USNM 563572; height 113 mm; diameter 113 mm.

2. Fragment of right valve, USNM 563574, rubber cast, showing frilled interstitial ribs.

3. Left dorsal margin of right, value, USN'M 563575, rubber cast, showing frilled terminal ribs.

4. Fragment of right valve, USNM 563576, rubber cast, showing a variation in the top surface of the ribs.

5. Incomplete anti decorticated right valve, USNM 563577, showing strong development of interstitial ribs; diameter
about 145 mm. Poul Creek formation, USGS 17733.

6. Fragment of left valve, USNM 563578, rubber cast, showing division of frills into 4 or 5 narrow rows; ribs de-
corticated on younger stages. Katalla formation, upper part, USGS 15852.

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PROFESSIONAL PAPER MM PLATE US

5 6

PECTJNIDS FROM THE POUL CREEK FORMATION AND THE UPPER PART OF THE KATALLA FORMATION

*7^101 O • M *1

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PLATE 36

(All flpimi slightly rodticod and from Poul Creek formation, U8GS M771, unless otherwise Indicated)

Figures 1, 3, 4, 6, 7. Patinopeclen (IMuyapecten) poulcreekentis MacNeil, n. sp. (p. 228).

1. Left ear of left valve, U8XM 563579, rubber cast.

3. Right ear of left valve, U8NM 563580, rubber cast.

4. Paratype, incomplete left valve, U8NM 563573, rubber cast; height of fragment 104 mm.

6. Fragment of left valve, X2, USNM 563581, rubber cast, showing juvenile sculpture.

7. Incomplete left valve, USXM 563582, rubber cast, showing variations in sculpture.

2. Palinopcctcn ( Lituyapeclen ) cf. P. ( L .) poulcreekcmis MacXeil (p. 228).

Shell material adhering to a large specimen, USXM 563585; part not shown an internal mold; height of en-
tire specimen 160 mm, nearly complete. Katalla formation, upper part, U8GS 15843.

5. PalinopeeUn ( Lituyapeclen ) poulcreekeruis MacNeil, subsp.? (p. 229).

Fragment of left valve, X 1, USNM 563584. Near base of Yakataga formation or top of Poul Creek
formation, U8GS D341 (T)

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PROFESSIONAL PAPEK 3.M PLATE 36

6 7

PECTINIDS FROM THE POUL CREEK FORMATION. THE UPPER PART OF THE KATALLA FORMATION.
AND THE UPPERMOST POUL CREEK OR LOWERMOST YAKATAGA FORMATION

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PLATE 37

Figures 1-7. Palinopecten ( Lituyapecten ) yakatagensi* (Clark) (p. 229).

1. Right valve, X 1, USNM 503586, rubber cast, incomplete and crushed, showing marginal denticles on the terminal
ribs. Yakataga formation, USGS 15425.

2. Incomplete right valve, slightly reduced, USNM 563587, rubber cast; note the weakly developed interstitial ribs;
height 104 nun. Yakataga formation, USGS 15425.

3, 4, 5. Fragment of left valve, USXM 563588, rubber cast, showing juvenile sculpture and adult ribs with strong
well-divided flanges. 3 and 5 are X2 enlargements of parts of 4 (X l). Yakataga formation, USGS 6693.

6. Incomplete left valve, XI, USXM 563589, rubber cast, a juvenile, showing early appearance of single frills on
terminal ribs. Yakataga formation, U8GS 15425.

7. Mature left valve, slightly reduced, USXM 563590, rubber cast, showing weaker and less divided flanges than
figure 4; note the strong marginal fold of left car; height 123 mm; diameter 123 mm. Yakataga formation,
USGS 17813.

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PECTINIDS FROM THE YAKATAGA FORMATION

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PLATE 38

Figures 1, 3. Patinopeclen (Lituyapeclen) falorensis MacNeil, n. sp. (p. 234).

1. Holotypc, right valve, slightly reduced, UC 34172; height 110 mm; diameter 115 mm. Falor formation of
Manning and Ogle (1950), UC A-4233.

3. Ilolotype, left valve, slightly reduced, UC 34171. Falor formation of Manning and Ogle (1950), UC A-4233.
2. Patinopeclen ( Lituyapeclen ) ponlcreekensis MacNeil, n. sp. (p. 228).

Incomplete hinge of a left valve, X 1, USX M 563583, rubber cast. Poul Creek formation, USGS M271.

4, 6. Patinopeclen (Lituyapeclen) yakatagensis (Clark) (p. 229).

4. Incomplete right valve, slightly reduced, USXM 563591, rubber cast. Yakataga formation, USGS 6695.

6. Hinge part of a decorticated right valve, slightly reduced; same specimen as plate 37, figure 7; destroyed in
acid to obtain mold of left valve. Yakataga formation, USGS 17813.

5. Patinopecten ( Lituyapecten ) poulcreekeneie MacXcil, subsp.? (p. 229).

Incomplete left valve, X 1, rubber cast. Float, upper part of Poul Creek formation or lower part of Yakataga
formation, CAS 29285.

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PROFESSIONAL PAPER 3M PLATE 3*

6 5

I’ECTINIDS FROM THE POfl. CHEEK FORMATION, THE YAKATAGA FORMATION, AND THE FA LOR
FORMATION OF MANNING AND OGLE, 1950 (CALIFORNIA)

«9I0I O -M -*

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PIRATE 39

Fint'RES 1, 3. Patinopecten ( Lituyapectcn ) lituynensh MacXeil, n. sp. (p. 231).

Moth from unnamed upper Tertiary formation, upper mudstone unit, USOS M270.

I. Holotvpe, a right valve, about X j«, USNM 563598, rubber cast; height 220 mm; diameter 210 mm.

3. Kars and left dorsal margin of a right valve, slightly reduced, USNM 563600, rubber cast, showing a variation
in sculpture of ears and ornamentation of marginal ribs.

2. Patinopecten ( Lituyapectcn ) yakatagensi * (Clark) (p. 229).

Incomplete right valve, XI, USNM 563592, rubber cast. Yakataga formation, USGS 17852.

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PROFESSIONAL PAPER 354 PLATE 30

PECTINIDS FROM THE YAKATAGA FORMATION AND THE UPPER MUDSTONE UNIT OF THE UNNAMED

UPPER TERTIARY FORMATION IN THE LITUYA DISTRICT

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w to

PLATE 40

(All from unnamed upper Tertiary formation, upper mudstone unit, USOS Mam)

Figures t -5. Polinoptclen ( IMuyapecten ) lituyaensis MacNcil, n. sp. (p. 231).

1. Left dorsal margin of right valve, X !, USNM 563001 , rubber cast, showing marginal frills on terminal ribs.
Right dorsal part of right valve, X 1, USNM 563602, rubber cast, showing marginal frills on terminal ribs.
Incomplete right valve, slightly reduced, USN'M 563603, rubber cast, a specimen without marginal frills on
terminal ribs.

4. Hinge of left valve, slightly reduced, USNM 563604, rubber cast.

5. Fragment of right valve, slightly reduced, USNM 563605, rubber cast, showing well-developed frilled interstitial
riblets.

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PROFESSIONAL PAPER X*>4 PLATE 4r.

PBCTINIDS FROM THE UPPER MUDSTONE UNIT OF THE UNNAMED UPPER TERTIARY FORMATION

IN THE LITUYA DISTRICT

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PLATE 41

Fig ore 1 . Paiinopecten ( Lituyapecten ) lituyaensis MacXeil, n. sp. (p. 231).

Incomplete right valve, slightly reduced, USXM 563606, rubber cast, showing ears and details of sculpture; note
greater asymmetry in advanced growth stages. Unnamed upper Tertiary formation, upper mudstone unit, USGS
M270.

2. Paiinopecten ( Liluyapectcn ) yaialagcnsis (?) (Clark) (p. 231).

Incomplete right valve, XI, USXM 563595, rubber cast. Unnamed upper Tertiary formation, lower sandstone-
siltstone unit, USGS D187 (T).

3. Paiinopecten ( Lituyapecten ) yakatagensis (Clark) (p. 229).

Incomplete left valve, X 1, USXM 563593, rubber cast. Yakataga formation, USGS 15425.

4, 5. Paiinopecten ( Lituyapecten ) cf. P. (L.) dillcri (Dali) (p. 235).

Right-valve fragments, X 1, USX'M 563612, 563613, in contact with and possibly same individual as left valve on plate
45, figure 1; ribs are undercut and without marginal frills or lamellae. Unnamed upper Tertiary unit, upper mud-
stone unit, USGS 7931.

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PROFESSIONAL PAPER 344 PLATE 41

PECTINIDS FROM THE YAKATAGA FORMATION AND THE LOWER SANDSTONE-SILTSTONE AND UPPER
MUDSTONE UNITS OF THE UNNAMED UPPER TERTIARY FORMATION IN THE LITUYA DISTRICT

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PLATE 42

Fiotrks 1, 2, 4. PalinopteUn ( Lituyapeclen ) lituyaensis MueXcil, n. sp. (p. 231).

1. Incomplete right valve, X 1, USXM 563607; stratigraphically the oldest known occurrence of the species.
Unnamed upper Tertiary formation, lower sandstone-siltstone unit, USGS D264 (T).

2. A X 2 enlargement of a part of the paratype, figure 4.

4. Paratype, a left valve, slightly reduced, USXM 563599, rubber cast; the mold from which this cast was made
was formed naturally by humic acids; specimen probably is laterally compressed. Unnamed upper Tertiary
formation, upper mudstone unit, USGS M270.

3. Palinopecten ( Liluyaptclen ) yakalagentit (Clark) (p. 230).

Fragment of a left valve, X 1, USXM 563594, rubber cast, with barnacles adhering, showing an interstitial riblet
and a weak middle row of denticles on one rib. Yakataga formation, USGS 17853.

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PROFESSION A I. PAPER 3i4 Pl.ATE 42

3 4

l’ECTIX IDS FROM THE YAKATAC.A FORMATION AND THE LOWER S A N DSTON E-SI LTSTON E AND UPPER
MUDSTONE UNITS OF THE UNNAMED UPPER TERTIARY FORMATION IN THE LITUYA DISTRICT

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PLATE 43

(All specimen* from unnamed upper Tertian' formation, upper mudstone unit, CS08 MOT)

Fioi'res 1-4. Palinopeclen (.Liluyaprctcn) liluyaeruis MacNeil, n. sp. (p. 231).

1. Incomplete left valve, slightly reduced, USXM 503603, rubber cast, showing three rows of denticles on some ribs
and several interspaces with weakly frilled interstitial riblets; note large barnacle bases.

2. Ixift ear and marginal sculpture of left valve, X 1, I’SN’M 503009, rubber cast.

3. l.eft-valve fragment, X 1, USNM 503610, rubber cast, showing a well-preserved pair of ears.

4. Lower part of a large left valve, slightly reduced, USNM 503611, rubber cast, possibly stretched laterally; the
mold of this specimen was partly destroyed to expose the right valve illustrated on plate 41, figure 1.

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PROFESSIONAL PAPER Sbi PLATE 48

PECTINIDS FROM THE UPPER MUDSTONE UNIT OK THE UNNAMED UPPER TERTIARY FORMATION

IN THE LITUYA DISTRICT

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Fioires 1,

PLATE 44

3. Palinopeclen ( Liluyapeclen ) purisimaentit (Arnold) (p. 233).

1. Incomplete right valve, slightly reduced, VC 15181, showing marginal denticles or lamellae on ribs; height 123
mm. I’urisima formation, l?C A-44I7.

3. Left valve of same individual, slightly reduced, showing 2 or 3 central ribs with a median sulcus, some juvenile
and adult ribs with worn single flanges on their crest.

4. Palinopeclen ( Lituyapeclcn ) falorensis MocNctl, n. sp. (p. 234).

2. Incomplete right valve, X 1, l”C 15977, showing broad adult ribs; height 130 mm. Purisima formation, VC
1788.

4. Fragment of left valve of same individual, X I, showing broad ribs and marginal denticles; remainder of left
valve an internal mold.

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PROFESSIONAL PAPER SM PLATE 44

3 4

PECTINIDS FROM THE PURISIMA FORMATION (CALIFORNIA)

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PLATE 45

FlOURK 1 . Palinopecten ( Lituyapecten ) cf. P. (L.) dilleri (Dali) (p. ‘235).

Fragment of a left valve, X 1, USN'M 563614, rubber cast, believed to be from the same individual as the right-valve
fragments shown on plate 41, figures 4, 5. Unnamed upper Teriary formation, upper mudstone unit, USGS 7931.

2, 4. Patinopeclen ( Lituyapecten ) falorentis MaeNeil, ti. sp. (p. 234).

2. Left valve of u half-grown specimen, slightly reduced, SU 8690a; height 92 mm; diameter 90 mm; ribs narrower
than normal. Purisima formation, Ano Nuevo Point, SU 29788.

4. Partial left valve of a large specimen, slightly reduced, SU 8691 ; same individual os right valve on plate 46, figure 1.
Puriaima formation one-fourth of a mile south of San Gregorio, SU 1095.

3. Patinopeclen {Lituyapecten) cf. P. (L.) yakatagensi* (Clark) (p. 231).

Left valve of a young specimen, X 1, USNM 563596, showing the juvenile sculpture persisting to a much later stage
than normal (see pi. 37, figs. 4, 6, 7) ; height 90 mm ; possibly a subspecies. Uppermost part of Poul Creek formation,
USGS 17733.

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PECTINIDS FROM THE POUL CREEK FORMATION. THE UPPER MUDSTONE UNIT OF THE
UNNAMED UPPER TERTIARY FORMATION IN THE LITUYA DISTRICT. AND FROM THE
PURISIMA FORMATION (CALIFORNIA)

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 344 PLATE 44

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PLATE 46

Fioi-res 1-4. Patinopecten ( Lituyapecten ) faloremi x MacNeil, n. sp. (p. 234).

1. Right valve, slightly reduced, SU 8691, narrower ribs than normal and with strong interstitial riblets; height
135 mm; diameter 142 mm; more complete than shown; same individual as plate 45, figure 4. Purisima forma-
tion, one-fourth of a mile south of San Gregorio, SU 1095.

2. Part of right valve, X 1, UC 31333, topotype; same individual as figure 3. Falor formation of Manning and
Ogle (1950), UC A- 4233.

3. Part of left valve, X 1 ; height 78 mm; diameter 75 mm; same individual as figure 2.

4. Right valve, slightly reduced, SIJ 8690-b; height 118 mm; diameter 112 mm. Purisima formation, Ano Nuevo
Point, SU 29788.

5. PatinoptcUn (LiluyaptcUn) cf. P. (L.) yakalngetuit (Clark) (p. 231).

Right valve, X I, USNM 563597, of the same individual as plate 45, figure 3. Uppermost part of the Poul Creek
formation, U8GS 17733.

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PROFESSIONAL PAPER PLATE «(i

PECTINIDS FROM THE POUL CREEK FORMATION, THE FALOR FORMATION OF MANNING AND OGLE.
I'JoO (CALIFORNIA). AND THE PURISIMA FORMATION (CALIFORNIA)

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Stratigraphic Occurrence of
Lituyapecten in Alaska

By DON J. MILLER

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 354-K

Detailed discussion of relevant Alaskan formations
containing Lituyapecten and description of collect-
ing localities

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CONTENTS

Abstract

Introduction

The formations

Katalla formation

Foul Creek formation

Pass

211

241

242
242
242

The formations — Continued

Yaketaga formation

Unnamed formation in the I-ituya district

Localities

References

ILLUSTRATIONS

Pace

Figure 4G. Generalized sections and tentative correlation
of middle and upper Tertiary formations in
the Gulf of Alaska Tertiary province, show-
ing approximate stratigruphic position of
collections containing large pectinid pele-
cypods 243

Figure 47. Map of the Gulf of Alaska Tertiary province,
showing localities at which large pectinid
pelecypods have been collected

Pa K*

245

248

Pat*

244

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SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

STRATIGRAPHIC OCCURRENCE OF LITUYAPECTEN IN ALASKA

By Don J. Miller

ABSTRACT

The Tertiary beds in the areas where Lituyapecten occurs
contain three gross units of deposition, the lower, middle, and
upper Tertiary units. Although these units indicate a simi-
larity in the succession of the type of sediments received in
different geographic districts, they are not supposed to be
strictly time divisions. The known occurrence of all types of
poctinids in these deposits is stated.

Formations containing Lituyapecten are discussed in more
detail. These include the Katatla formation in the Katalla
district, the Poul Creek and Yakataga formations in the Yuka-
taga district, and an unnamed upper Tertiary formation in the
Lituya district.

A generalized correlation chart and a map of the Gulf of
Alaska Tertiary province arc included; fossil localities arc
located stratigraphically and geographically on them.

INTRODUCTION

The fossil pectinid pelecypods described in this
paper are from rocks of Miocene and Pliocene age
exposed in the Katalla, Yakataga, Malaspina, and
Lituya districts bordering the northeast shore of the
Gulf of Alaska (fig. 47). In this area there is an
arcuate lowland and foothills belt that is 300 miles
long and 2 to 40 miles wide. The sedimentary rocks
of Tertiary age in this belt are exposed or are inferred
to underlie lowland areas covered by ice or uncon-
solidated deposits (Grj T c, Miller, and Payne, 1951,
p. 159-162). It is of historical interest that the "man-
teau royal” found in the Lituya district in 1786 by a
naturalist in the expedition commanded by the French
explorer La Pfrouse (1797, p. 189) is the earliest known
record of a fossil pecten on the west coast of North
America. In compiling the first geologic map of
Alaska, Grewingk (1850, p. 99-100, map, p 1 . 2) cited
this shell as evidence for the presence of rocks of Ter-
tiary age on the northeast coast of the Gulf of Alaska.

The sequence of Tertiary rocks exposed in the Gulf
of Alaska Tertiary province comprises deposits, mainly
clastic, laid down in the Yakataga geosvncline (Payne,
1955) during each of the epochs from Eocene through
Pliocene. The known thickness of the sequence at

the outcrop exceeds 25,000 feet locally. Significant
changes in the environment of deposition during the
Tertiary period are reflected in the distinctive lithologic
character and organic content in three major divisions
of the Tertiary sequence.

The lower Tertiary unit consists of nonmarine,
brackish, and marine strata, interbedded and inter-
tonguing and consisting largely of siltstone, arkosic
sandstone, and coal. It contains a continental flora
and a marine invertebrate fauna of tropical to sub-
tropical aspect. Only one fragmental specimen of a
pectinid is known to have been collected from beds
assigned to the lower Tertiary unit; it may be a
Patirwpecien.

The lower Tertiary unit includes the Stillwater and
Kushtaka formations, the lower part of the Tokun
formation in the Katalla district, and an unnamed
siltstone and the Kulthieth formation (at the top)
in the Yakataga and Malaspina districts.

The middle Tertiary unit consists mainly of marine
strata deposited in water of shallow to moderate
depth. This unit is characterized by massive poorly
sorted or unsorted concretionary siltstone and mudstone
and by widespread but generally thin beds of glau-
conite sandstone and water-laid volcanic breccia or tuff.
The marine invertebrate fauna suggests warm, temperate
to subtropical waters. Small mud pectens ( Delecto -
pecten have been collected at several localities from
beds in the lower and middle parts of the middle
Tertiary unit. At least one species of large pecten,
Patinopecten (Lituyapecten) poulcreekensis, occurs in
the uppermost part of the middle Tertiary unit, or
in beds transitional between the middle and upper
Tertiary units.

The middle Tertiary unit includes the upper part
of the Tokun formation and lower and middle parts
of the Katalla formation in the Katalla district, and
the Poul Creek formation in the Yakataga district.
Possibly the lowermost part of the unnamed beds
constituting the Tertiary sequence in the Lituya

241

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242

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

district belongs to the same sedimentary regimen as
the middle Tertiary unit.

The upper Tertiary unit is wholly marine and
consists of sandstone, siltstone and conglomerate
deposited in shallow-water, and marine tillite. The
tillite, a massive sandy mudstone containing marine
fossils and randomly distributed coarse, ice-rafted
clastic fragments is interbedded with and grades
laterally into the normal marine sedimentary rocks
(Miller, 1953a, p. 22-35). The lithologic evidence
for supposed glaciation in the Gulf of Alaska region
in late Tertiary time is supported by a marine in-
vertebrate fauna that is generally indicative of cool,
temperate to boreal water and that includes many
species whose closest living relatives are found in
the Gulf of Alaska or farther north. Pcctinids are
a conspicuous and locally abundant element of the
marine invertebrate fauna in the upper Tertiary unit.

The upper Tertiary unit includes the upper part
of the Katalla formation in the Katalla district, the
Yakataga formation in the Yakataga and Malaspina
districts, and at least the upper part of the Tertiary
sequence in the Lituya district.

The pectinids described in this paper are from the
following stratigraphic units: (a) The upper part of
the Katalla formation in the Katalla district; (b) the
uppermost part of the Poul Creek formation in the
Yakataga district; (c) the Yakataga formation in
the Yakataga and Malaspina districts; and (d) an
unnamed formation of late Tertiary age in the Lituya
district. Uncertainties regarding exact correlation of
these formations (fig. 46) within the Gulf of Alaska
Tertiary province and also within the Oregon and
Washington Tertiary section are due mainly to dis-
continuity of outcrops and lack of detailed field infor-
mation, to scarcity or poor preservation of fossils
in some parts of the formations, to ecological differ-
ences between the dominantly cold-water fauna in
the Gulf of Alaska region and the more temperate
faunas of the Tertiary sections on the Pacific coast
farther south, and to the difference of opinion as to
the classification of the Pacific-coast Tertiary sections
with reference to the international time scale.

THE FORMATIONS
KATALLA FORMATION

Martin (1905, p. 13; 1908, p. 27-37) proposed the
name Katalla formation for a section of rocks of Ter-
tiary age exposed in the hills south of Bering Lake in
the Katalla district (formerly culled the Controller Buy
region). Martin was uncertain of the exact age of
the Katalla formation and of its stratigraphic posi-
tion relative to the sequence of Tertiary rocks ex-

posed north of Bering Lake, which he divided, in as-
cending order, into the Stillwater, Kushtaka, and Tokun
formations. More recent detailed field investigation
(Miller, Rossman, and Hickcox, 1945; Miller, 1951)
including a restudy of the fossils by several paleontolo-
gists, indicates that the approximately 8,600 feet of
marine strata designated as the Katalla formation by
Martin in the type area arc Oligoeene and Miocene in
age, and that the basal unit of interbedded siltstone and
sandstone is equivalent to the upper part of the Tokun
formation.

The sequence exposed in the isolated outcrop area of
the Suckling Hills, in the extreme southeast part of the
Katalla district, is equivalent to the middle and upper
part of the Katalla formation of Martin in the type
area, and may also include some younger beds. Ix>t
15852, containing a fragment of a large pecten identi-
fied as Palinopecten ( Lituyapecten ) poulcreekensis , was
collected from sandstone near the contact of a predom-
inantly sandy unit with the underlying predomin-
nantly silty unit. This contact is tentatively corre-
lated with the contact between the predominantly
sandy upper part of the Katalla formation and the pre-
dominantly silty middle part in the type area, and with
the contact between the Yakataga and Poul Creek for-
mations in the Yakataga district. Another specimen
of what may be the same species of pecten (USGS loc.
15843) was found in a loose concretion on the east flank
of theSuekling Hills. The predominantlysiltysequence
exposed at this locality is thought to be equivalent to
the middle or even the lower part of the middle silty
unit of the Katalla formation, but the concretion may
have come from higher in the section.

POUL GREEK FORMATION

The Poul Creek formation of Taliaferro (1932,
p. 754-756), as redefined recently (Miller, 1957), in-
cludes about 6,100 feet of marine interbedded sandstone
and siltstone of Oligoeene and early Miocene age. At
most localities in the Yakataga district, the contact of
the Poul Creek formation with the overlying Yakataga
formation is gradational through a stratigraphic interval
of 50 to 200 feet in which the typical reddish-brown-
weathering silty rocks of the Poul Creek are interbedded
with typical gray-weathering sandstone and siltstone
of the Yakataga. This change in lithology coincides
with a marked change in the marine invertebrate fauna;
the characteristic deeper and wanner water fauna of
the middle Tertiary unit gives way to the character-
istic shallower and colder water fauna of the upper
Tertiary unit. The pcctens from USGS localities
17733, M271, and CAS 29261 collected on Yakataga
Reef, are from a 50-foot-thick transitional unit between

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STRATIGRAPHIC OCCURRENCE OF UTTTYAPECTEN IN ALASKA

243

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Fiourb 46. Generalised sections and tentative correlation of middle and upper Tertiary formations In the Gulf of Alaska Tertiary province, showing approximate stratigraphic po&ition of collections containing large

pi ct i Mid pc key pods.

244

SHORTER CONTRIBUTION'S TO GENERAL GEOLOGT

Digitized by Google

Kiourk 47. — Map of the Gulf of Atoka Tertiary province, showinj; localltlos at which large pcctinld pelecypods have been collected.

STRATIGRAPHIC OCCURRENCE OF LITUYAPECTEN IN ALASKA

245

the Poul Creek and Yakataga formations. The con-
tact here was arbitrarily drawn at a more conspicuous
change in lithologic character above the pectcn-boaring
siltstone and silty sandstone. The fragment of peetcn
in USGS D341 (T) came from similar muddy sandstone
in the transitional zone at another locality.

YAKATAGA FORMATION

Taliaferro (1932, p. 756-762) proposed the name
Yakataga formation for the younger Tertiar} 7 marine
strata above the Poul Creek formation in the Yakataga
district. Miller (1957) redefined the basal contact of
the Yakataga formation in the Yakataga district, and
Plafker and Miller (1957) extended the name to include
strata in the Malaspina district that were originally
named the Pinnacle system by Russel (1891, p. 1 70—
173; 1893, p, 26). As now recognized the Yakataga
formation totals a minimum of 10,000 feet, possibly

15.000 feet or even more, of marine sedimentary rocks,
chiefly sandstone, siltstone, and conglomeratic sandy
mudstone, of Miocene and Pliocene(?) age. In the
Yakataga district, interbedded sandstone and siltstone
predominate in the lower part of the formation through
a section ranging in thickness from 3,500 to at least
5,500 feet; above this section, conglomeratic sandy
mudstone is the predominant rock type. In the cen-
tral and eastern part of the Malaspina district, only the
upper part of the Yakataga formation crops out; this
part rests with angular unconformity on rocks of early
Tertiary age and older.

The most characteristic and abundant pectinid in the
Yakataga formation, PatinopecUn ( Lituyapecten ) yaka-
tapensis (Clark), has been found mainly in sandstone
beds, but also in siltstone and mudstone in the lower

3.000 to 3,700 feet. Another pectinid, probably Pati-
nopecten ( Pnlinopeden ) cavrinus (Gould), has been
found about 7,000 feet above the base of the formation
in the Yakataga district and in the uppermost part of
formation in the Malaspina district.

UNNAMED FORMATION IN THE LITUYA DISTRICT

The sequence of rocks of Tertiary age exposed in the
Lituya district has been provisionally divided (Miller,
1953b) into four lithologic units as follows: (a) Con-
cretionary marine siltstone with thin interbeds of sand-
stone that is 1,200 feet to possibly as much as 4,400 feet
thick ; (b) volcanic rocks, conglomerate, sandstone, and
siltstone that are nonmarine und marine and as much as
1,200 feet thick; (c) interbedded sandstone and
siltstone that are marine, 600 feet to at least 2,400 feet;
(d) marine conglomeratic sandy mudstone interbedded
with sandstone and siltstone that is at least 8,000 feet.

Units a and b are believed to be at least in part equiva-
lent in age and to grade into each other, as both units
at different places rest unconformably on pre-Tertiary
rock? and are overlain with apparent conformity by
unit c. The upper part of unit c grades laterally into
the lower part of unit d. The two units together con-
stitute a formation of late Miocene(?) and Pliocene age.
This unnamed formation is lithologically similar to the
Yakataga formation, but unit c is probably entirely
or at least in large part younger than the interbedded
sandstone-siltstone unit, that constitutes the lower part
of the Yakataga.

One species of an exceptionally large pec ten, Patino -
pecten ( Lituyapecten ) lituya-emis MacNeil, n. sp., has
been collected at two widely separated localities in the
Lituya district from near the base of tho unnamed
Tertiary formation. A specimen doubtfully referred
to P. ( Lituyapecten ) yakatagensi $ was found at another
locality. A fragment of another species of large pecten,
Patinopecten ( Lituyapecten ) cf. P. (L.) dilleri (Dali), was
found higher in the formation at one locality.

LOCALITIES

The available fossils from the Tertiary rocks exposed
in the Gulf of Alaska province were collected over a
period of nearly 70 years, maiuly by geologists engaged
in areal mapping and under conditions that allowed
neither time nor facilities for collecting and transporting
a large number of specimens. As a consequence of
these circumstances, as well as the generally poor preser-
vation of the fossils and the hardness of the Tertiary
rocks, many of the fossils, particularly the large pec-
tinids, are fragmentary. On the other hand the con-
spicuous, large pectinids probably were rarely over-
looked where any fossils were collected.

The following descriptions of Alaskan localities at
which fossil pectinids were collected include the essen-
tial part of the original geographic description, followed,
where possible or necessary, by supplementary infor-
mation in parenthesis locating the collection on the
most detailed published topographic map available
in 1958. The stratigraphic assignments are the writer’s.
The California localities were compiled by MacNeil.

ALASKA LOCALITIES
KaUIU district

USOS Ctnozoic loc.

15843. Creek on southeast flank of Suckling Hills, 3.2 miles N.

26° E. of mouth of Kiklukh River, Bering Glacier
quadrangle. Collector, D. J. Miller, 1945. Float,
Katulla formation.

15852. Creek on northwest flank of Suckling Hills, 3.1 miles N.

48° W. of mouth of Kiklukh River, Bering Glacier
quadrangle. Collector, D. J. Miller, 1945. Katalla
formation, upper part.

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246

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Yakatafa district

Yakataga diatrict— Continued

USOS Cenozoic lot.

6693.

6695.

15425.

15437.

17733.

17813.

17840.

17841.

17852.

17853.

D256 (T).

D341 (T).

Bluff on south bunk of White River one-half a mile
below foot of (White River] glacier (2.43 miles N.
4° E. of mouth of Fulton Creek, Bering Glacier
A-4 quadrangle). Collector, A. G. Maddren,
1913. Yakataga formation, about 1,800 ft above
base.

From sandy shalo at intake tunnel of the White Riv-
er Mining Co.’s flume, North Fork of White River
(about 4.8 miles N. 87° W. of M unday Peak, Ber-
ing Glacier A-3 quadrangle). Collector, A. G.
Maddren, 1913. Yakataga formation, about 3,500
ft above base.

North flank and crest of Yakataga Ridge (5.7 miles
S. 72° W. of Mount Eberly, Bering Glacier A-3
quadrangle). Collector, M. S. Walton, Jr., 1944.
Yakataga formation, about 500 ft above base.

Unnamed creek on north flank of and parallel to
Yakataga Ridge (0.3 mile X. 16° E. of peak 2430
near west end of Yakataga Ridge, Bering Glacier
A-4 quadrangle). Collector, E. M. Spieker, 1944.
Poul Creek formation, near top, and possibly ba-
sal part of Yakataga formation.

Yakataga Reef, about 700 ft N. 30° E. of highest
rock on the reef (1.53 miles S. 56° E. of mouth of
Mink Creek, Bering Glacier A-4 quadrangle; game
locality as M271). Collector, D. J. Miller, 1948.
Poul Creek formation, upper 50 ft.

Small stream entering Kulthieth River from the east,
2.4 miles N. 53° E. of junction of Kultheith and
Kaliakh Rivers, Bering Glacier quadrangle. Col-
lector, D. J. Miller, 1947. Yakataga formation,
probably lower part.

South flank of Kulthieth Mountain, 0.7 mile S. 32° E.
of peak 3437, Bering Glacier quadrangle. Collec-
tor, R. B. Johnson, 1947. Yakataga formation,
at least 2,400 ft above base.

Gulch on south face of ridge at Sunshine Point, 2.0
miles S. 53° E. of junction of Kulthieth and Kaliakh
Rivers, Bering Glacier quadrangle. Collector,
R. B. Johnson, 1947. Yakataga formation, lower
part.

Gulch on south flank of Kulthieth Mountain, 0.85
mile S. 17° E. of peak 3437, Bering Glacier quad-
rangle. Collector, D. J. Miller, 1947. Yakataga
formation, at least 900 ft above base.

Gulch on south flank of Kultheith Mountain, between
points 0.8 mile S. 34° E. and 1 mile S. 6° W. of peak
3437, Bering Glacier quadrangle. Collector, D. J.
Miller, 1947. Float, lower part of Yakataga
formation.

Small outcrop at margin of Yakataga Glacier, at
head and on south side of North Channel of the
Yakataga River, Bering Glacier A-4 quadrangle.
Collector, D. L. Rossman, 1953. Yakataga
formation.

Ridge at head of Cotton Creek; altitude 3,800 ft.,
1.35 miles X. 30° E. of peak 4014 on Duktoth
Mountain, Bering Glacier A-4 quadrangle. Col-
lector, J. E. Heppert, Standard Oil Co. of Cali-
fornia, 1954. Probably Yakataga formation, near
base; may be at top of Poul Creek formation.

USOS Ctnozoit lot .— Continued

M271. Yakataga Reef, along strike of beds that intersect the
shoreline at a point 700 ft N. 30° E. of the highest
rock on the reef (1.53 miles S. 56° E. of mouth of
Mink Creek, Bering Glacier A-4 quadrangle; same
locality as 17733). Collector, D. J. Miller, 1958.
Poul Creek formation, 25 to 50 ft below top.

California Unit. lUtrktlty) toe.

3859. Yakataga Reef, from a sandstone about 800 ft above
lowest reef exposure (about 1.36 miles S. 56° E. of
mouth of Mink Creek, Bering Glacier A-4 quad-
rangle). Collector, N. L. Taliaferro, 1920. Ya-
kataga formation, about 300-350 ft above base.

California Acad. Sti. lot. 1

29244. West [south] base of Kulthieth Mountain, at mouth
of small stream coming from cirquelike hanging
valley, 3 to 4 miles west of Duktoth River (about
1 mile S. 6° W. of peak 3437, Kulthieth Mountain,
Bearing Glacier quadrangle). Float, Yakataga
formation, lower part.

29246. Gray sandy conglomerate exposed on west side of
Miller Creek near mouth of small west tributary,
about 1)4 miles north (upstream) from first
outcrop exposed along west side of creek (about
1.4 miles S. 41° W. of peak 3394 at head of Miller
Creek, Bering Glacier A-4 quadrangle). Yaka-
taga formation, probably about 3,300 ft. above
base.

29248. Yakataga River (Bering Glacier A-4 quadrangle).

Float, from Poul Creek formation and probably
from Yakataga formation.

29251. East side of Porcupine Creek, 1)4 miles upstream
(north) from mouth (about 2 miles S. 31° E. of
peak 3394 at head of Miller Creek, Bering Glacier
A-4 quadrangle). Yakataga formation, lower
part.

29253. Lower 1 mile of Opooch Creek above junction with
Yakataga Glacier (along unnamed creek on the
north flank of and parallel to the west end of
Yakataga Ridge, Bering Glacier A-4 quadrangle).
Float, from upper part of Poul Creek formation
and from the Yakataga formation, probably only
the lower part.

29256. Clear Creek (Bering Glacier A-3 and A-4 quadran-
gles). Float, from Yakataga formation.

29257. Yakataga Reef, from pecten zone just above a
pebble conglomerate which projects farther into the
sea than any other of the reef beds (about 1.36
miles S. 56° E. of mouth of Mink Creek, Bering
Glacier A-4 quadrangle). Yakataga formation,
about 350 ft. above base.

29261. Yakataga Reef, from shaly mudstone zone just
above massive sandstone (along strike of beds
that intersect the shoreline at a point 1.53 miles
S. 56° E. of Mink Creek, Bering Glacier A-4
quadrangle. Poul Creek formation, within 30
ft. of top.

1 All collections liy flcltl jxuty reprcavniine The Standard Oil Co. of California.
The Tidewater Associated Oil Co., and The Onion Oil Co. of California, 193H.

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STRATIGRAPHIC OCCURRENCE OF LITUYAPECTEN IN ALASKA

247

Yak*tag» dlatfkC— Continued
California Acad. Sef. Joe. 1 — Continued

29264. Twomile Creek, below forks (Bering Glacier A-4
quadrangle). Float, from upper part of Poul
Creek formation and possibly also from lower
part of Yakataga formation. The lithologic
character of matrix attached to the large pecten
suggests Poul Creek.

29270. Hamilton Creek (Bering Glacier A-4 quadrangle).

Flout, from upper part of Poul Creek formation
1 and lower part of Yakataga formation.

29274. Outcrop of brown sandstone just above rivers edge
on east side of big bend on White River, 1)4 to
1)4 miles upstream from the mouth (about 1.85
miles N. 14 c E. of mouth of White River, Bering
Glacier A-4 quadrangle). Near base of Yakataga
formation or near top of Poul Creek formation.

29276. South side of White River across from Three Cabins
camp (about 2.55 miles N. 16° W. of mouth of
Fulton Creek, Bering Glacier A-4 quadrangle).
Yakataga formation, about 1,200 ft. above base.

29277. Nearly horizontal beds in canyon on upper part
of White River, about one-quarter of a mile
upstream from end of old flume (about 4.6 miles
N. 84° W. of Mundav Peak, Bering Glacier A-3
quadrangle). Yakataga formation, about 3,700
ft. above base.

29280. Umbrella Reef, from shore outward through an
estimated stratigraphic thickness of 500 feet
(about 0.3 mile west of mouth of I.awrence Creek,
Bering Glacier A-3 quadrangle). Yakataga for-
mation, about 6,000 to 6,500 ft. above base.

29283. I.awrence Creek (Bering Glacier A-3 quadrangle).

Float, from lower part of Yakataga formation
and upper part of Poul Creek formation.

29285. Poul Creek (Bering Glacier A-3 quadrangle).

Float, from upper part of Poul Creek formation
and lower part of Yakataga formation.

29287. Munday Creek (Bering Glacier A-3 quadrangle).

Float, from upper part of Poul Creek formation
and possibly from lower part of Yakataga for-
mation. The lithologic character of matrix at-
tached to the pecten suggests Poul Creek.

29290. Mouth of tributary creek entering Johnston Creek
on the cast side about one-quarter of a mile
upstream from General Petroleum Co. drilling
camp (about 3.9 miles S. 34° E. of Munday
Peak, Bering Glacier A-3 quadrangle). Float,
from all but the lowest part of the Poul Creek
formation and probably from the lower part of
the Yakataga formation. The lithologic char-
acter of matrix attached to the pecten suggests
Poul Ccek formation.

29294. Little River (Bering Glacier A-3 quadrangle).

Float, upper part of Poul Creek formation and
lower part of Yakataga formation.

i All collect kirn by add party reprcwntlng The Stumlaril Oil Co. of California.
The Tidewater Associated Oil Co., and The Union Oil Co. of California. MSS,

MaUrtplnm district

USOS CnotaSt ItK.

1)263 (T). Point Glorious, about 1.68 miles N. 68° W. of peak
5520, Mount St. Elias quadrangle. Collector,
George Plafker, 1953. Yakataga formation, upper
part.

1)336 (T). Point Glorious, probably same locality as D263 (T).
Collector, I. C. Russell, 1890.

Uluya district

7931. Sea cliff cut by stream 6)4 miles southeast of Lituya
Bay, about 500 ft from beach (about 2 miles
southeast of mouth of Steelhead Creek, Mount
Fairwcather quadrangle). Collector, J. B. Mcrtie,
Jr., 1917. Unnamed upper Tertiary formation
about 3,200 ft above base; upper mudstone unit.

D174 (T). Southwest shore of Cenotaph Island, 3,500 ft S. 70°
W. of easternmost cape of Island (Lituya Bay, Mount
Fainveuther quadrangle). Collector, D. J. Miller, 1952.
Unnamed upper Tertiary formation about 1,070
ft above base; upper mudstone unit.

D187 (T). Ocean beach reef, Icy Point measured section, 1.04
miles, S. 22° W. of mouth of Kaknau Creek (Palma
Bay, Mount Fairweather quadrangle). Collector,
J. F. Seitz, 1952. Unnamed upper Tertiary
formation about 800 ft above base; probably
lower sandstone-siltstone unit.

1)223 (T). Cliff at east margin of glacier at Cape Fairweather,
about 3.8 miles N. 80° W. of Mount Escures,
Mount Fairweather quadrangle; same locality as
1)264 (T). Collector, C. E. Kirschner, Standard
Oil Co. of California, 1953. Unnamed upper
Tertiary formation, probably in lower sandstone-
siltstone unit.

1)264 (T). Cliff at east margin of glacier at Cape Fairweather,
about 3.8 miles N. 80° W. of Mount Escures,
Mount Fairweather quadrangle; same locality as
1)223 (T). Collector, D. J. Miller, 1953.

Unnamed upper Tertiary formation, probably in
lower sandstone-siltstone unit.

M270. Southwest shore of Cenotaph Island, along strike of
beds from a point 0.83 mile N. 84° W. of eastern-
most cape in the island to a point 0.65 mile S. 70°
W. of the same cape; Lituya Bay, Mount Fair-
weather quadrangle. Collector, D. J. Miller, 1958.
Unnamed upper Tertiary formation 1,050 to 1,090
ft above base ; upper mudstone unit.

Californi* local l tips

California Unit'. (Ptsk/ltf) let.

1780. In the sea cliffs and small reefs )« to )• mile due west
of the mouth of Ano Neuvo Creek, San Mateo
County, Calif. B. Martin, collector. No date.
Purisima formation, Pliocene.

1788. In the sea cliffs at the mouth of Purisima Creek, San
Mateo County, Calif. B. Martin, collector. No
date. Purisima formation, Pliocene.

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248

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

California locallllea-CoiUlmint
California Unit. (lUrttlro) lot — Continued

A— 1233. Bank of Boulder Creek from 100 yd south to 200
yd north of bridge near ‘‘Beckstine Ranch'’ (Wiggins
Ranch), in about a 20 ft stratigraphic interval,
about 10 miles southeast of Blue Lake, Humboldt
County, Calif. B. A. Ogle, collector, 1946. Falor
formation, Pliocene.

A— 1343. Halfway between San Gregorio and Pescadero Lagoon
on the const, San Mateo County, Calif. M. K.
Gebert, collector. No date. Purisimn formation,
Pliocene.

A-4417. North side of San Gregorio Lagoon, San Mateo

County, Culif. J. W. Durham, collector, 1948.
Purisima formation, Pliocene.

California Volt. ( Lot Ansdtt) lot.

8072 (plesiotypc No. 309). India and Upas Streets, San Diego,

Calif. E. H. Quale, collector,

1931. San Diego formation,

Pliocene.

Stanford Uniccnity catalog No.

1095. San Gregorio beach, one-<iuartcr of a mile south of
mouth of San Gregorio Creek, San Mateo County,
Calif. Enos Preston, collector, 1907. Purisima

formation, Pliocene.

4821. Ford across Eel River halfway between Scotia and
Nanning Creek, Humboldt County, Calif. H. Han-
nibal, collector, 1913. “Wildcat series" of Lawson;
probably from the Rio Dell formation of Ogle,
Pliocene.

4828. Top of ridge between two legs of trail fork in Dry
Canyon, an east branch of Tapo Canyon, 3.8 miles
north of Santa Susaua, north side of Simi Valley,
Santa Susana quadrangle, Ventura County, Calif.
George Boulware, collector, 1920. Pliocene.

4837. In Boulder Creek for one-quarter of a mile up and
one-quarter of a mile down from Maple Creek post
office (Boulder Creek and Maple Creek are in the
Blue Lake quadrangle), Humboldt County, Calif.
H. Hannibal, collector, 1913. Falor formation,
Pliocene.

4922. Ano Nuevo Point, San Mateo County, Calif. R. Ar
nold, collector, 1903. Purisima formation, Pliocene.
4932. East branch of south fork of Eel River from mouth of
Panther Creek up creek for 1 mile, Humboldt
County, Calif. W. G. Cooper and H. Hannibal,
collectors, 1913. “Wildcat series" of Lawson;
probably from the Rio Dell formation of Ogle,
Pliocene.

4936. Mouth of large arroyo northwest of Elephant Mesa,

Scammon Lagoon quadrangle, Lower California.

B. F. Hake, collector, 1921. Pliocene.

4937. Same as 4932.

4942. Yellow sandstone, Casmalia Hills, 2.6 miles N. 50° E.
of “BM 95" (B.\l 95 is located in San Antonio Creek
about 4.2 miles south of Casmalia — can be found on
pi. 1 in U.8. Geol. Survey Bull. 322), Todos Santos
y San Antonio, Santa Barbara County, Calif.

C. F. Tolman, collector, 1924. “Pliocene.”

29788. Ano Nuevo Point, San Mateo County, Calif. R.

Arnold and W. R. Hamilton, collectors, 1903.
Purisima formation. Pliocene.

OlifornU localities— Continued

California Acad. Sci. Soc.

1 17. “Wildcat series,” Humboldt County, Calif. B. Martin,
collector. 1912.

2095. Same as Stanford Univ., 4936.

34391. Tomkins Hill gasfield, secs. 23 to 24, T. 3 N., R. 1 E.,
Humboldt County, Calif. T. W. Cameron, collec-
tor, 1955. “Wildcat Pliocene.”

VSGS Ccnotolc lot.

3363 (USNM 164846). Bluffs opposite Rio Del, Eel River,
Humboldt County, Calif. J. S. Dillcr,
collector, 1906. “Wildcat scries” of
Lawson; lower part of the Rio Dell
formation of Ogle, Pliocene.

14649. Graciosa Ridge, 450 ft south-southwest of Union Oil
Co. Graciosa 3 well, Orcutt field, Santa Barbara
County, Calif. W. P. Woodring, collector, 1939.
Cebada fine-grained member of the Careaga sand
stone, Pliocene.

USNM cotalo; No.

560053. 1.8 miles S. 35° E. of Casmalia, Santa Barbara County,
Calif. L. M. Clark, collector, no date. Foxen
mudstone, Pliocene.

REFERENCES

Clark, B. L., 1932, Fauna of the Poul and Yakataga formations
(upper Oligocene) of southern Alaska: Geol. Soc. America
Bull. 43, p. 797-846, pis. 14-21, 1 fig.

Grewingk, Constantin, 1850, Bcitrag zur Kenntniss der oro-
graphischen und geognostischen Beschaffcnhcit der Nord-
West-Kuste Amerikas mit den anlicgenden Inseln: Russ.
K. min. Gesell. St. Petersburg Verb. 1848-49, p. 76-424,
pis. 1-7. [1-3 are maps, -1-7 fossils. |

Gryc, George, Miller, D. J., and Payne, T. G., 1951, Possible
future petroleum provinces of North America; chapter on
Alaska: Am. Assoc. Petroleum Geologists Bull., v. 35, p.
151-168, figs. 2-5.

La POrouse, J. F. de G., 1797, Voyage de La Pdrouse autour
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Martin, G. C., 1905, The petroleum fields of the Pacific Coast of
Alaska with an nccount of the Bering River coal deposits:
U.S. Geol. Survey Bull. 250, 64 p., 7 pis., 3 figs.

1908, Geology and mineral resources of the Controller

Bay region, Alaska: U.S. Geol. Survey Bull. 335, 141 p., 10
pis., 2 figs.

Mertie, J. B., Jr., 1931, Notes on the geography and geology of
Lituya Bay, Alaska: U.S. Geol. Survey Bull. 836-B, p.
117-135, 1 fig.

Miller, D. J., 1951, Geology and oil possibilities of the Katalla
district, Alaska: U.S. Geol. Survey open-file report, 66 p.,
5 figs.

1953a, Late Ceuozoic marine glacial sediments and marine

terraces of Middleton Island, Alaska: Jour. Geol., v. 61, p.
17 -40, 2 pis., 4 figs., 7 tables.

— 1953b, Preliminary geologic map of Tertiary rooks in the

southeastern part of the Lituya district, Alaska. Cor-
related columnar sections of Tertiary rocks in the Lituya
district, Alaska: U.S. Geol. Survey open-file report.

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STRATIGRAPHIC OCCURRENCE OF LITCT APECTEN IN ALASKA

249

Miller, D. J., 1957, Geology of the southeastern part of the
Robinson Mountains, Yakataga district, Alaska: U.S. Geol.
Survey Oil and Gas Inv. Map OM-187.

Miller, D. J., Uossman, D. L., and Hickcox, C. A., 1945, Pre-
liminary report on petroleum possibilities in the Katalla
area, Alaska. Geologic and topographic map and sections
of the Katalla area, Alaska: U.S. Geol. Survey Prelim.
Rept., 18 p., map.

Payne, T. G., 1955, Mesozoic and Cenozoic tectonic elements of
Alaska: U.S. Geol. Survey Misc. Geol. Inv. Map 1-84.

Plafker, George, and Miller, D. J., 1957, Reconnaissance geology
of the Malaspina district, Alaska: U.S. Geol. Survey Oil
and Gas Inv. Map OM-189.

Russell, I. C., 1891, An expedition to Mount St. Elias, Alaska:
Natl. Geog. Map., v. 3, p. 53-204, pis. 2-20, 8 figs.

1893, Second expedition to Mount St. Elias, in 1891,

U.S. Geol. Survey Ann. Rept. 13, pt. 2, p. 1-91, map.

Taliaferro, N. I-., 1932, Geology of the Yakataga, Katalla, and
Nichawak districts, Alaska: Geol. Soc. America Bull., v.
43, p. 749-782, 14 figs.

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