Ali Al-Juboury

The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These successions are represented by Gir Bir (Cenomanian-early Turonian), Wajna (late Santonian) and Mushorah (early Campanian) Formations. The succession has affected by early burial near-surface, unconformity-related and deep burial diagenesis represented by cementation, neomorphism, dolomitization, dedolomitization, silicification, authigenesis of glauconite and pyrite, compaction, micritization, solution and porosity formation. The common porosity types are intergranular, fenestral, intercrystalline, moldic, vuggy, channel and fracture. Three porosity zones (I, II, and III) are identified depending on variation in gamma ray which reflects their shale content. The upper part of zone (II) is highly porous and regarded on the main reservoir unit in the middle and upper parts of the Gir Bir Formation. Fracture and moldic and vuggy dissolution ...

The Middle Miocene Fatha Formation (previously Lower Fars Formation) in northern Iraq was deposited in a broad and shallow foreland basin adjacent to the Zagros and Taurus Mountains. It forms a transgressive-regressive sequence comprising numerous shallowing-upward cycles of alternating mudrocks, limestones, gypsum and/or anhydrite and halite. These cycles reflect rapid changes in accommodation space in settings that ranged from open and restricted hypersaline marine to continental (sabkha and fluvio-deltaic). In the marginal parts of the basin, continental siliciclastics (red and variegated marls, silts and fine sandstones) represent either aeolian deposition or a combined lagoonal- and/or fluvial-dominated delta system. Eustasy, rather than tectonics, caused the high-frequency cyclicity seen in the Fatha Formation. We present twelve sections dominated by evaporites from the Sinjar and Fatha sub-basins to represent the main lithologic constituents of the formation. Our detailed ana...

Abstract The petrography and geochemistry of clastic rocks collected from two sections from the Baluti Formation northern Iraq, have been investigated to infer the depositional environment of the Late Triassic Baluti Formation. Petrographic study of the carbonate unit shows that they consist mainly of heterogeneous poorly sorted grainstones and packstones, ooids, intraclasts, peloids, bioclasts and green algae (Halimeda). The abundant and heterogeneous size of these constituents suggests a subtidal lagoon/oolitic shoal depositional environment with an open marine water circulation. Trace element concentrations of the shales and marlstones reveal a wide difference in the depositional environment. The paleoclimate proxies (C-value, Sr/Cu, Rb/Sr, Ga/Rb, and Sr/Ba ratios) and presence of illite suggest a hot and arid to semiarid climates during the deposition of the Buluti sediments, which coincide with the Late Triassic global warming. The combined use of the Cd/Mo and Co*Mn proxies indicate the deposition mainly in open marine settings on the continental margin associated with upwelling and subordinate restricted marine settings. Trace element redox proxies (V/(V + Ni), Th/U, V/Cr, Ni/Co, and V/Ni ratios indicates anoxic to dysoxic to marginally oxic marine conditions. This difference in paleoredox conditions is likely to arise from the variation in the hydrographic conditions of the depositional basin including water depth, upwelling oxidation degree in the water column and salinity.

The Ubaid cultural phenomena (6500–4200 BC) of southern Mesopotamia has been used to characterise other archaeological sites in the Arabian Gulf region. The aim of this inquiry is to explore the nature of the interaction between the homeland of the Ubaid and the wider Gulf region. Through the use of a non‐destructive portable Xray fluorescence (pXRF) spectrometer, this study seeks to characterise and identify the chemical and mineralogical compositions of the ceramic assemblage from the Bahra 1 site of the As‐Sabbiya region, Kuwait. The chemical results demonstrated that a combination of six trace elements [rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb) and barium (Ba)] occur significantly enough to delineate clay‐based artifact groups—local red coarse from Ubaid, while the mineralogical analysis confirms the pXRF result and identifies the source of the raw materials and temper as well. Also, the comparison between the Ubaid and Bronze Age assemblage results suggests that potters used different clay resources within their own regions and/or production techniques. Contact the author for more inquires

The samples of the mineralization of Pb-, Zn-, and Fe-sulfides were collected from three localities (Dure, Lefan, in the northern Thrust zone; and Sinjar, in the Foothill zone) in Northern Iraq. The geochemical recognition using X-ray diffraction (XRD) affirms the presence of the ore deposit sulfides (pyrite, sphalerite, galena, smithsonite, and cerus-site). The characterization of mineral chemistry using electron microprobe analysis (EMPA) gives a clear and exact percentage of each element in each mineral. Fluid inclusions are mostly liquid H 2 O and/or water vapor, which may also contain lesser soluble salts and slightly ore elements. Some fluid inclusions contain CO 2 vapor. This occurrence suggests the presence of two immiscible phases due to boiling at the time of their trapping. They are of epithermal system. The homogenization temperatures and salinities obtained for fluid inclusions can be comparable to those reported for the Mississippi Valley Type (MVT) lead-zinc deposits. It is concluded from the petrographic evidence, fluid inclusions and stable isotope data that lead-zinc mineralization was formed due to deeply circulating high-temperature fluids (brines) within the source basin, or later on by tectonic processes, which possibly contribute in leaching metals from either the diagenesis of host rocks or dewatering of deeper buried siliciclastic beds.

Clay minerals investigation is conducted using X-ray diffraction and scanning electron microscopy from the upper Cretaceous Shiranish Formation and lower Tertiary Kolosh Formation at two sections in Dohuk and Shaqlawa, northern Iraq. The study revealed the presence of smectite, palygorskite, illite, smectite-chlorite mixed layers, chlorite, and kaolinite. Smectite and palygorskite found to be formed authigenically in the marl of the Shiranish Formation, whereas, other minerals are detrital in origin especially in the Kolosh Formation. The mineral variation reflects the environmental changes from Cretaceous to Tertiary times. Variation in source rocks and change in drainage conditions may lead to increase in the effectiveness of leaching processes and hence transformation of smectite to palygorskite. These changes also effects on the prevalence of inherited or detrital types of clay minerals in the Kolosh sediments.

The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These successions are represented by Gir Bir (Cenomanian-early Turonian), Wajna (late Santonian) and Mushorah (early Campanian) Formations. The succession has affected by early burial near-surface, unconformity-related and deep burial diagenesis represented by cementation, neomorphism, dolomitization, dedolomitization, silicification, authigenesis of glauconite and pyrite, compaction, micritization, solution and porosity formation. The common porosity types are intergranular, fenestral, intercrystalline, moldic, vuggy, channel and fracture. Three porosity zones (I, II, and III) are identified depending on variation in gamma ray which reflects their shale content. The upper part of zone (II) is highly porous and regarded on the main reservoir unit in the middle and upper parts of the Gir Bir Formation. Fracture and moldic and vuggy dissolution features in addition to karstic and fissure features are responsible for the porosity increase in the fractured reservoir unit.

The source rock potential of "hot shales" in the Silurian Akkas Formation in Iraq has been investigated by numerous studies, but the reservoir potential of sandstone intervals in the formation has received less attention. This study investigates the sedimentology and geochemistry of sandstones from the Akkas Formation in the Akkas-1, Akkas-3 and KH5/6 wells in western Iraq. The composition of sandstone samples from the Akkas wells is similar; in general they are classified as sub-litharenites, quartz-arenites and sub-arkoses. Scanning electron microscopic analysis identified extensive microporosity and good pore connectivity, suggesting that these sandstones have the potential to form hydrocarbon reservoirs. The sandstones from the KH5/6 well are more lithic-rich than those from the Akkas wells and are classified as sub-litharenites. They have larger, more connected pores and better reservoir potential. Low permeability shale intervals within the Akkas Formation and the conformably-underlying Ordovician Khabour Formation form barriers to hydrocarbon migration into the Akkas and Khabour sandstones. Hydrocarbon migration from the Akkas "hot shales" in the Akkas field is therefore controlled by faulting and fracturing. Petrographic and whole rock geochemical analyses showed that the composition of sandstones in the Akkas Formation is different from that of sandstones in the Khabour Formation. The chemical alteration index ranges from 77.39 to 87.06%, indicating intense weathering of the provenance area before sandstone deposition. The studied samples are texturally mature which indicates good potential for fluid storage capacity. A decrease in feldspar content in the Akkas Formation is attributed to possible recycling of sediments from the Khabour Formation into the Akkas Formation following the Hirnantian glaciation, or to longer distance transportation from the source area.

Rock magnetic properties have been investigated across the Paleocene/Eocene boundary in two distally separate sections of Paleogene marine sedimentary rocks from Iraq, namely the Sinjar and the Shaqlawa sections. The sediments at the studied sections belong to the Aaliji and the Kolosh formations respectively, which were previously examined for their biostratigraphy by the authors using planktonic and benthonic foraminifera to delineate the Paleocene/Eocene (P/E) transition. Measured magnetic properties include; bulk magnetic susceptibility, hysteresis cycles, isothermal remnant magnetization (IRM) acquisition, and thermomagnetic curves analysis. Rock-magnetic results (i.e. low magnetic coercivity component) indicate greigite as the main magnetic phase at Aaliji rocks, while a mixture of magnetite and greigite with high magnetic coercivity has been observed at Kolosh clastics. Magnetic susceptibility is induced by related to both biogenic minerals (mainly at Aaliji Formation) and transported terrigenous material sources. Multi varied magnitude phases of high bulk rock magnetic susceptibility observed in both formations along PETM lithosomes are attributed to two sources: greigite or biogenic iron oxides source and increase in terrigenous discharge source as inferred by anoxic to suboxic iron-sulfate-reducing conditions and lithological change respectively. Both sources referred to some of environmental conditions associated with Paleocene-Eocene thermal maximum events such as methane dissociation, water stratification, enhanced hydrological and weathering cycles.

This paper explores the production characteristics and provenance of Islamic glazed pottery in the Adiabene region of northeastern Mesopotamia. Samples cover the entire time span under study, i.e., from the Early to the Late Islamic periods. Analytical techniques such as ceramic petrography, powder X-ray diffraction, scanning electron microscopy, and X-ray microanalysis were employed to determine compositional (mineralogical and chemical) and technological characteristics. Based on the comparison of ceramic fabrics with up-to-date knowledge of regional geology, local plain pottery, and the published petrography of Mesopotamian ceramics, several provenance groups of glazed pottery (and one group of unglazed pottery) in the sample collection, originating from the Zabs catchment, the middle course of the Tigris (Samarra?) and the middle and lower course of the Tigris (Baghdad and/or Basra?) were defined. Dynamic oscillations in the ratio of regionally produced and imported pottery enable a detailed study of the socioeconomic differences between the Early and Middle Islamic periods.

Chalki basalts as a small body of volcanic rocks have green to grayish green color due to their nearly complete alteration to chlorite. The essential minerals of Chalki basalt to andesitic basalts are plagioclase (labradorite, An 51-61 ; andesine, An 35 to An 42 ; and oligoclase, An 22). Moreover, there is sodic plagioclase (albite, An 0.1 to An 04) whose coexistence with the other more calcic plagioclase means that albitization had occurred. The other essential mineral is pyroxene (endiopside, en 66-68 wo 27-28 fs 05-06 ; and subcalcic augite, en 72 wo 14 fs 14). Olivine (Fo 80-81) is also present. According to the NiO content (0.11-0.12 wt%) in olivine grains, they are interpreted to be originated tectonically. The prevalent chlorite in all the samples is mainly diabantite and penninite, indicating chloritization after the ferromagnesian olivine and pyroxene. Serpentine (type lizardite and chrysotile) is also recorded as lesser alteration product after the forsteritic olivine. Rare secondary hornblende (type magnesiohornblende) is also found. The spinel group as accessory minerals is defined as magnetite, chromian magnetite, and chromian spinel giving the imprints of their metamorphic origin due to low temperature sub-sea metamorphism and also of alpine type.

Evaporites (gypsum and anhydrite) of the middle Miocene age (Fat'ha Formation) form one of the main sulfate cap rocks in the Middle East oilfields. Detailed petrographic and diagenetic investigations accompanied with geochemical analysis of these evaporite rocks in Mosul and Kirkuk areas of northern Iraq have revealed that nodular gypsum is the dominant type, whereas laminated, structure-less, and secondary (selenite and satin spar) also are present. Nodular gypsum was deposited in a very shallow, arid, and semi-restricted lagoonal environment which has undergone influx and reflux processes, while laminated gypsum may represent pulses of freshwater into the lagoonal basin of Fat'ha Formation. Low strontium values of the secondary and laminated gypsum may attribute to their secondary origin by hydration processes from the original anhydrite. Based on petrographic, diagenetic, and petrophysical (porosity and permeability) properties, it appears that the efficiency of the Fat'ha sulfates as petroleum cap rocks increases with increasing nodular growth and compaction degree. The occasional presence of bitumen inclusions with both nodular gypsum and host materials relates to early leakage of the hydrocarbons which were being halt due to the growing and packing of nodules and host materials.

Calcareous nannofossils were documented from the upper part of the Cretaceous Balambo Formation at northern Iraq aiming to determine an evidence for the Oceanic Anoxic Event. Detailed investigation of the calcareous nannofossils led to the identification of twenty-four species. Regarding these data, Discolithus litterarius (Górka, 1957) identified at the studied interval with the age of Early Aptian. Early Aptian assemblages are dominated by nannoconids that drop sharply within the D. litterarius nannofossil zone, which may be related to the nannoconid crisis recorded in the Early Aptianat the other parts of the world. This event is coinciding by decrease in CaCO3 content and higher content of the Total Organic Carbon (TOC).

ABSTRACT: Graptolites from the upper ‘hot’ shale from the Akkas-1 well, western Iraq demonstrate that it is of early Wenlock Monograptus riccartonensis Zone age, somewhat younger than the Llandovery age previously ascribed to it. Chitinozoans from the same sample are poorly preserved and can be identified only tentatively. The riccartonensis Zone was characterized globally by lowered sea-levels during an interval (Sheinwoodian) of otherwise high eustatic sea-level. Increased TOC levels have been recognised at this stratigraphical level also at localities on the palaeocontinents Avalonia and Baltica.

The study determines the shape, area, and discharge properties and other factors of morphometric analysis and drainage pattern to characterize the optimum location for salt harvesting in the salt ponds in Meha area, northwest Sharqat city, Iraq. The morphometric analysis confirms the idea of the upward leakage of salt rich water from the deep ground water along the surface of deep fault. The hydrogeological data of groundwater leakage encourage the method of harvesting salt by evaporation ponds. Also, the relationship between hydrochemical parameters, their variation with the period of evaporation, increasing of Na + and Cl – percentages, and decreasing of other component support the salt production in the area.

Modal analysis, bulk-rock geochemistry and Fe-Ti mineral chemistry of the Late Triassic Carpathian Keuper sandstones indicate that their mineralogy being mainly quartz-dominated, with variable amounts of feldspars and rock fragments and are classified as quartz arenites, sub-litharenites and sub-arkoses, suggesting derivation mainly from acid igneous rocks, gneisses and older sandstones. These are common constituents of the basement rocks in the area studied and the surroundings. Their bulk-rock geochemistry supports the petrographic results and indicates that they are virtually Fe-rich, lithic sandstones/quartz arkosic sandstones. Fe-Ti oxide minerals chemistry suggests a metamorphic rather than igneous sources. Based on the mineralogical and geochemical indicators, the probable provenance of the Keuper sandstones was mainly the metamorphic and igneous rocks of the crystalline cores of the Western Carpathians and the foreland of the Bohemian Massif which were weathered and deposite...

ABSTRACT Triassic–Jurassic sedimentary successions (Baluti and Sarki formations) in northern Iraq record a variety of environmental changes that may be related to global Triassic–Jurassic (Tr/J) boundary events. The diversity of some benthic fauna decreases through the transitional boundary beds. The coastal marine environment of the lower part of the Baluti Formation is followed by shallower tidal flat and supratidal marginal marine environments at the transitional boundary with the Jurassic-age Sarki Formation. The alternating calcareous mudrocks and dolomitic limestones of the transitional succession are overlain by a succession of calcareous mudrocks and dolomicrites that form a dolocrete bed in the latest Triassic. The early Jurassic carbonates (lower part of Sarki Formation) were deposited in a shallow-marine to lagoonal environment. Geochemical evidence supports this interpretation. TOC% increases towards the Tr/J boundary and the lower part of the Sarki Formation. This increase can be interpreted as resulting from the primary precipitation of dolocrete as palaeosol horizons. The variations in the oxygen isotope ratios mainly reflect the facies and diagenetic effects. Th/K ratio is generally constant and shows an increase in the calcareous mudrock beds of the upper part of the Baluti Formation, possibly related to the degradation of K-bearing clay minerals. Low Th/U ratios are due to the depletion in thorium, typical of many marine carbonates rather than to an increase in authigenic uranium. This explanation is also corroborated by the presence of abundant fossils in some of the studied carbonates. Copyright © 2013 John Wiley & Sons, Ltd.

... Pleistocene river terraces Pleistocene Mukdadiyah & Bai Hassan formations (Bakhtiari group) U.Miocene Injana (Upper Fars) Formation M.Miocene Fat , ha(Lower Fars) Formation L.Miocene(Serkagrd,Euphrates, Dhaban & Jenbe) Formations Palecoene(Pilaspi, Avanah & ...

ABSTRACT In the northeast of Zakho City, Northern Iraq, the host rocks of Pb–Zn deposits are composed predominantly of dolomites with subordinate dolomitic limestone intervals. This study is focused on the dolomites of the Bekhme Formation (Upper Campanian) carbonate-hosted Pb–Zn deposits. The amount of dolomites, however, increases toward the mineralized zone. Dolomites are dominated by replacement dolomite with minor dolomite cements. Petrography study allowed identification of six different dolomite textures. These are (1) fine crystalline, planar-s (subhedral) dolomite, RD1; (2) medium to coarse crystalline, planar-e (euhedral) to planar-s (subhedral) dolomites, RD2; (3) medium crystalline, planar-s (subhedral) to nonplanar-a (anhedral) dolomites, RD3; (4) coarse crystalline, planar-s (subhedral) to nonplanar-a (anhedral) dolomites, RD4; (5) planar (subhedral) void-filling dolomite cements, CD1; and (6) nonplanar (saddle) void-filling dolomite, CD2. The RD1, RD2, RD3, and RD4 dolomite textures are replacive in origin and are volumetrically the most important types, whereas CD1 and CD2 dolomites with sparry calcite are commonly cements that fill the open spaces. Although the dolomites of the Bekhme Formation are not macroscopically observed in the field, their different types are easily distinguished by petrographic examination and scanning electron microscopy. It was observed that the dolomites of the Bekhme Formation are formed in two different diagenetic stages: the early diagenetic from mixing zone fluids at the tidal–subtidal (reef) environments and the late diagenetic from basinal brines which partially mixed with hydrothermal fluids at the shallow-deep burial depths. The latter occurs often with sphalerite, galena, and pyrite within mineralized zone. These dolomite types are associated base-metal mineralization (Mississippi Valley type).

ABSTRACT Hydrocarbon generation potential and porosity types of the Middle Triassic Geli Khana Formation in Jabal Kand-1 (JK-1) well and from outcrop section at Ora of northern Iraq are investigated. Total organic carbon, pyrolysis, and maturation assessment such as thermal alteration index (TAI) and vitrinite reflectance (Ro%) for 19 shale samples are conducted. The analyses showed a sufficient amount of organic matter (OM) occurs in JK-1 specifically. According to the obtained samples from the pyrolysis analysis of the studied samples, the existing organic matters in well (JK-1) are composed of a mixed of kerogen type II–III and III; while type IV in outcrop section which found in post mature state, indicating dry gas window. The estimated TAI for the studied section ranged between 3.3 in and 3.7 in JK-1 and 3.3–4 in Ora section. Additionally, the maturity derived information from vitrinite reflectance supported that the Geli Khana Formation is in dry gas window and post mature stage in both sections due to the average ratio of (Ro %) which is between 1.35 and 2 %. The porosity types in the carbonate successions of the formation include; fracture, moldic, intergranular, intramatrix, vuggy, intercrystalline, channel and fenestral birds-eye porosities. These types enhance the reservoir characteristics of the carbonate succession of the formation.