Middle Miocene

... the Periadriatic–Drava fault in the marginal zone of Pohorje Mts., 7 km along the southern marginal fault of the Pannonian basin in the vicinity of Karlovac, and 10 km along the branching fault of the Periadriatic–Drava fault marking the southern border of the Kalnik–Ivan ica Mts. ...

The NNE-SSW striking Giudicarie Fault System (composed of the Northern and Southern Giudicarie Fault and the Meran-Mauls Fault) represents a distinctive bend and offset in the Periadriatic Fault System (PFS). It terminates the E-W striking Tonale Fault Zone to the east, and the ESE-WNW striking Pustertal-Gailtal Fault to the west. Along the Giudicarie Fault System Oligocene tonalitic bodies occur, subsumed under the term 'Oligocene Tonalitic lamellae'. Along the southern part of the Northern Giudicarie Fault only a few < 50 m thick and 200 m long lenses crop out, often strongly affected by brittle deformation. So far no tonalitic bodies have been found between the locality Rumo (Val di Non) and Pawigl (south of Meran), i.e. for some 20 km. From Pawigl to the NE the lenses are more continuous, up to 150 m thick and less affected by brittle deformation. Fission Track analyses was carried out on samples from tonalitic lenses along the Northern Giudicarie Fault and the Meran ...

The Romeral Fault System (RFS) extends 1600 km from Barranquilla-Colombia to Talara city-Peru and before the Pliocene. In the Middle Eocene RFS defi ned the northwestern border of the South America plate, being originated by a triple junction rift- rift- rift occurred from lower to middle Jurassic, when the South American sector separated from Chortis, Oaxaca and Yucatan blocks. From Late Mesozoic until Early Paleocene, the Paleo Pacifi c plate converged on NW South America corner being subducted when an anomalous thick oceanic crust, represented by the Caribbean plate, was accreted extinguishing gradually from the North of Peru to the North of Colombia. The collision generated a transtensive fi eld stress in back arc region, due to the ancestral Central Cordillera rising in continental border. The RFS rocks suffered low grade metamorphism and some rocks of extinct subduction zone suffered metamorphic inversion. During Late Paleogene until Early Miocene, the convergence South Americ...

A thick sequence of volcaniclastic sediments drilled at site 953 during Ocean Drilling Program (ODP) Leg 157 northeast of Gran Canaria (Canary Islands) contains an almost complete magneto-stratigraphy back to the shield stage of the island 14.8 Ma ago. Onshore, a sequence of reversals has been identified and dated in 19 dominantly peralkaline rhyolitic ignimbrites, one rhyolitic, and one basaltic lava flow of the Mogán Group (13.35–13.95 Ma), which overlie basalt flows of the island's shield stage (>14 Ma). The magneto-stratigraphy of the ignimbrites onshore has been correlated with the marine magneto-stratigraphy at site 953, determined in syn-ignimbritic volcaniclastic turbidites, which were deposited practically synchronously immediately following the entry of the parent pyroclastic flows into the sea around the circumference of the island. The four polarity intervals recorded in the sequence of the Mogán Group ignimbrites correspond to C5ACr, C5ACn, C5ADr and C5ADn. Single crystal 40Ar/39Ar-age determinations of the ignimbrites bracketing the polarity changes gave the following ages and uncertainties for the reversals C5AD (t) (13.95±0.07 Ma), C5AC(o) (13.89±0.08 Ma), and C5AC(t) (13.47±0.09 Ma). The newly dated polarity changes fit and refine the Miocene age model proposed in the global polarity time scale.

Cockatoos are the distinctive family Cacatuidae, a major lineage of the order of parrots (Psittaciformes) and distributed throughout the Australasian region of the world. However, the evolutionary history of cockatoos is not well understood. We investigated the phylogeny of cockatoos based on three mitochon- drial and three nuclear DNA genes obtained from 16 of 21 species of Cacatuidae. In addition, five novel mitochondrial genomes were used to estimate time of divergence and our estimates indicate Cacatuidae diverged from Psittacidae approximately 40.7 million years ago (95% CI 51.6–30.3 Ma) during the Eocene. Our data shows Cacatuidae began to diversify approximately 27.9 Ma (95% CI 38.1–18.3 Ma) during the Oligocene. The early to middle Miocene (20–10 Ma) was a significant period in the evolution of modern Australian environments and vegetation, in which a transformation from mainly mesic to xeric habitats (e.g., fire-adapted sclerophyll vegetation and grasslands) occurred. We hypothesize that this environmen- tal transformation was a driving force behind the diversification of cockatoos. A detailed multi-locus molecular phylogeny enabled us to resolve the phylogenetic placements of the Palm Cockatoo (Probosciger aterrimus), Galah (Eolophus roseicapillus), Gang-gang Cockatoo (Callocephalon fimbriatum) and Cockatiel (Nymphicus hollandicus), which have historically been difficult to place within Cacatuidae. When the molecular evidence is analysed in concert with morphology, it is clear that many of the cockatoo species’ diagnostic phenotypic traits such as plumage colour, body size, wing shape and bill morphology have evolved in parallel or convergently across lineages.

Die Lage der Gemeinde Winden zwischen
den Abhängen des Leithagebirges und
dem Westufer des Neusiedler Sees weist
nicht nur in historischer, sondern auch aus geowissenschaftlicher
Sicht überaus interessante Aspekte
auf. Die Positionierung an einer uralten Nord-Süd
Hauptverkehrsader, der Bernsteinstraße1, sowie
die Verfügbarkeit von diversen Rohstoffen und ein
fruchtbarer Boden stellten günstige Bedingungen
für eine prosperierende Gemeinde dar. Neben dem
Weinbau war in der Vergangenheit aber vor allem
die Gewinnung von Baugesteinen von großer
wirtschaftlicher Bedeutung. Vor allem die nahezu
weißen, fein- bis grobkörnigen miozänen Leithakalke
wurden in mehreren, bis in römische Zeiten
zurückgehenden Steinbrüchen in großer Menge
abgebaut. Die morphologischen und bodenkundlichen
Eigenheiten der Gemeinde stehen naturgemäß
in engem Zusammenhang mit dem geologischen
Aufbau dieser Region. Die Beschreibung
der geologischen Verhältnisse des Windener Untergrundes
erfordert ein etwas weiteres Ausholen,
da die vorliegende Situation eng mit der jüngsten
geologischen Geschichte des Ostalpen–Karpaten–
Gebirgssystems im Neogen zusammenhängt. Besonders
hervorzuheben sind hier die Entstehung des
Wiener Beckens, des Eisenstädter Beckens und der
Kleinen Ungarischen Tiefebene.

The study provides a regional seismic interpretation and mapping of the Mesozoic and Cenozoic succession of the Lusitanian Basin and the shelf and slope area off Portugal. The seismic study is compared with previous studies of the Lusitanian Basin. From the Late Triassic to the Cretaceous the study area experienced four rift phases and intermittent periods of tectonic quiescence. The

Eobalaenoptera harrisoni, gen. et sp. nov., is described from a partial skeleton collected from the middle Miocene Calvert Formation of Virginia. Characteristics of this taxon, particularly of the petrosal, indicate that the new whale is a member of the clade that includes the Balaenopteridae (rorquals) and Eschrichtidae (gray whales) to the exclusion of “cetotheres” and the Balaenidae (right whales). Some of the probable synapomorphies of this clade include an elongate pars cochlearis, a tubular internal auditory meatus, the greater petrosal nerve foramen on the tympanic side of the petrosal, the stylomastoid fossa extending onto the posterior process of the petrosal, no medial groove on the pars cochlearis, four digits on each forelimb, depressed supraorbital processes, and ascending processes of maxillae extending onto the vertex. The approximate 14-million-year age of the specimen makes it the oldest known member of the clade by some 3 to 5 million years, and extends the fossil record of this clade closer to the divergence time estimated by some recent molecular studies.

We describe an early middle Miocene (late Langhian) terrestrial mollusc fauna from Nowa Wieś Królewska at Opole in Silesia (Poland). This survey is based on the rich collection stored in the Natural History Museum in Vienna and represents the first revision of this classical fauna. The assemblage is extraordinarily diverse and comprises 82 gastropod species and one bivalve species. About 56% of the taxa are known so far only from Nowa Wieś Królewska, emphasizing the preeminent position of this fauna within the European Neogene. The fauna reveals taxonomic affinities with early and early middle Miocene faunas. Stratigraphic overlap of several species and genera would suggest a correlation with the mammal biozone MN 5; integrating mammal data, however, indicates correlation with the biozone MN 6. This discrepancy is explained best by the lack of other adequately revised European MN 6 mollusc faunas. Consequently, the fauna from Nowa Wieś Królewska is proposed here as type of a MN 6 mollusc fauna in Central Europe. As such, this fauna represents the best-documented terrestrial mollusc fauna from the late Miocene Climate Optimum. Semi-quantitative abundance data of the terrestrial gastropods suggests the presence of ephemeral ponds and fens that formed on Cret-aceous limestones, surrounded by forested environments with leaf litter and dead wood. Occidentina gen. nov., Mennoia gen. nov., Neubertella gen. nov. and Eurocystina gen. nov. are described as new genera. Martinietta kadolskyi sp. nov., Carychium stworzewiczae sp. nov., Gastrocopta (Albinula) polonica sp. nov., Leiostyla piserai sp. nov., Vertigo antipygmaea sp. nov., Mennoia sculpturata sp. nov., Neubertella pulchra sp. nov., Aegopinella depressula sp. nov., Eurocystina nordsiecki sp. nov. and Vitrea angustaeumbilicata sp. nov. are introduced as new species. •

In this paper, we describe a non-marine mollusk fauna deriving from late middle Miocene (late Serravallian; Sarmatian) deposits of western Serbia. The assemblage encompasses a diverse land snail fauna with twenty-four species, along with four species of freshwater pulmonate gastropods and one bivalve species. While the aquatic snails are ubiquitous elements in Europe during the middle Miocene, the terrestrial gastropod fauna, consisting of both common and rare species, offers the first comprehensive insight into land snail diversity on the Balkan Peninsula during that time and permits conclusions on regional biogeography. The fauna shows high affinities to the middle Miocene faunas of central Europe and shares only few elements with western and eastern European and Anatolian assemblages. Ecologically, the freshwater mollusks point to a standing or slowing moving, probably highly vegetated, lacustrine environment. The land snails indicate the presence of humid forests around Lake Vračević, which is in line with current climatic reconstruction for the Sarmatian of southeastern Europe. ?Vertigo vracevicensis Neubauer & Harzhauser sp. nov. and Pisidium mionicense Neubauer, Harzhauser & Mandic sp. nov. are introduced as new species. Discus costatus (Gottschick, 1911) is shown to be a junior objective synonym of Discus solarioides (Sandberger, 1872). •

Bathymetric, 9.5-kHz long-range sidescan sonar (OKEAN), seismic reflection and sediment-core data are used in the analysis of two tectonic troughs south of Crete, Eastern Mediterranean Sea. Here, up to 1.2 s two-way travel time (TWTT) of strata have accumulated since the Middle Miocene in association with extension in the South Aegean region. The study area comprises >100-km- long by >25-km-wide basins filled by sediments subdivided into two seismic units: (1) an upper Unit 1 deposited in sub-basins which follow the present-day configuration of the southern Cretan margin; (2) a basal Unit 2, more than 500 ms (TWTT) thick, accumulated in deeper half-graben/grabens distinct from the present-day depocentres. Both units overlap a locally stratified Unit 3 comprising the pre-Neogene core complex of Crete and Gavdos. In this work, the interpreted seismic units are correlated with the onshore stratigraphy, demonstrating that denudation processes occurring on Crete and Gavdos in response to major tectonic events have been responsible for high sedimentation rates along the proximal southern Cretan margin. Consequently, topographically confined sedimentary units have been deposited south of Crete in the last 12 Ma, including turbidites and other mass-flow deposits fed by evolving transverse and axial channel systems. Surface processes controlling facies distribution include the direct inflow of sediment from alluvial-fan systems and incising mountain rivers onto the Cretan slope, where significant sediment instability processes occur at present. In this setting, seismic profiles reveal eight different types of stratigraphic contacts on basin-margin highs, and basinal areas show evidence of halokinesis and/or fluid escape. The acquired data also show that significant changes to the margin’s configuration occurred in association with the post-Alpine tectonic and eustatic episodes affecting the Eastern Mediterranean.

A quantitative paleobathymetric study of Badenian foraminifera was carried out from Tekeres-1 and Tengelic-2 boreholes, north of the Mecsek Mts., SW Hungary. Paleobathymetric data, based on plankton/benthos ratio provided input for the analysis of the subsidence history. The biostratigraphic framework is mainly provided by calcareous nannoplankton (zones NN5–NN7). Changes in sedimentation rates are also considered, partly calculated from number of benthos per unit sediment, and partly estimated from the changes of lithofacies. Relative sea-level changes are calculated from changes of paleowater depth and coeval sedimentary thickness. The result is examined as the sum of accommodation space created by subsidence and eustasy. In that period of time eustatic changes were about an order of magnitude smaller than changes created by movements of the basin floor. According to our model in early Badenian (up to the half of NN5 nannozone) a very rapid transtension-related subsidence of about 500 m occurred. This was interrupted by a short period of uplift of minor magnitude at about the first third of NN5 zone; thereafter, subsidence continued and the basin floor reached its deepest position. Still within the NN5 nannozone (Early Badenian) a significant uplift occurred, terminating the life of the deep basin. The Late Badenian (NN6) is characterized by a relatively small rate of subsidence and presumably quiet tectonism. During this period bathymetric changes are thought to be controlled primarily by eustatic changes. The first uplift – only interrupting subsidence – is regarded as the result of the change of the local stress field because of convergence along the curvature of strike slip faults. The second uplift, which stopped the subsidence of the basin floor is thought to be of a regional character and is attributed to the compression generated between Tisza and Alcapa tectonic units.

Messinian evaporites, which resulted from the salinity crisis during the final closure of the Mediterranean Sea, are exposed in SE Turkey. These evaporites formed in two isolated sub-basins, Iskenderun-Arsuz (IA) and Hatay-Samandağ (HS), which belong to different depositional configurations and tectonic structures. The Neogene fill of these sub-basins consists of a thick sedimentary succession that started with Early Miocene terrestrial clastics, followed by reefs (Middle Miocene) and shallow water siliciclastics (Tortonian - Early to Late Miocene) and finally Messinian evaporates. These sub-basins accumulated in a diverse range of depositional environments from very shallow to deeper water. Evaporite facies in the IA sub-basin consist of sabkhas, saline lagoons and ponds. They are mainly represented by chemical deposits such as scattered gypsum nodules and balls, nodular bedded gypsum, laminated gypsum (Type-A) and selenites (Type-S1). Evaporites in the HS sub-basin mainly consist of detrital gypsum composed of gypsum laminae (Type-B, C), gypsum arenite-rudites and deeper water selenites (≤ 20 m), and resedimented selenites (Type-S2), which were deposited on a sulfate platform with a slope-basin transitional zone. Secondary gypsum with alabastrine and porphyroblastic textures as well as satin spar veins is commonly associated with the sabkha-type evaporites of the IA sub-basin. Deeper-water clastic evaporites of the HS sub-basin have generally remained as primary gypsum or have only been slightly affected by diagenetic alterations. The isotope values ( 87/86Sr; δ 18O SMOW; and δ 34S CDT) from the different kinds of gypsum lithofacies of the sub-basin are similar to those of the Messinian evaporites in other peri-Mediterranean basins, indicating an origin from marine water without external or basinal contributions. The Messinian evaporites examined in this paper are overlain by Early Pliocene (Zanclean) deposits composed of shallow- and deep-water siliciclastics and carbonates with local intercalations of Lago-Mare-type strata. Throughout the Messinian evaporitic stage, the IA sub-basin was mainly comprised of shallow water evaporites, while the HS sub-basin underwent deepening related to regional tectonics induced by the Dead Sea Fault during the construction of the Hatay Graben.