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Citation for published item:q rz ntiD iF nd elEtu ouryD eFsF nd oleikh eiD F nd ermees hD F nd totheriD tF nd ekko D fw nd y idD eFuF nd ellenD wFfF nd end¡ oD F nd vimont D F nd do nD wF nd esentiniD eF nd ittnerD wF nd ezzoliD qF @PHITA 9 he iuphr tesE igrisEu run river system X proven n eD re y ling nd dispers l of qu rtzEpoor forel ndE sin sediments in rid lim teF9D i rthEs ien e reviewsFD ITP F ppF IHUEIPVF Further information on publisher's website:httpsXGGdoiForgGIHFIHITGjFe rs irevFPHITFHWFHHW Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract: We present a detailed sediment-provenance study on the modern Euphrates-Tigris-Karun fluvial system and Mesopotamian foreland basin, one of the cradles of humanity. Our rich petrographic and heavy-mineral dataset, integrated by sand geochemistry and U-Pb age spectra of detrital zircons, highlights the several peculiarities of this large source-tosink sediment-routing system and widens the spectrum of compositions generally assumed as paradigmatic for orogenic settings. Comparison of classical static versus upgraded dynamic petrologic models enhance the power of provenance analysis, and allow us to derive a more refined conceptual model of reference and to verify the limitations of the approach. Sand derived from the Anatolia-Zagros orogen contains abundant lithic grains eroded from carbonates, cherts, mudrocks, arc volcanics, obducted ophiolites and ophiolitic mélanges representing the exposed shallow structural level of the orogen, with relative scarcity of quartz, Kfeldspar and mica. This quartz-poor petrographic signature, characterizing the undissected composite tectonic domain of the entire Anatolia-Iranian plateau, is markedly distinct from that of sand shed by more elevated and faster-eroding collision orogens such as the Himalaya. Arid climate in the region allows preservation of chemically unstable grains including carbonate rock fragments and locally even gypsum, and reduces transport capacity of fluvial systems, which dump most of their load in Mesopotamian marshlands upstream of the Arabian/Persian Gulf allochemical carbonate factory. Quartz-poor sediment from the AnatoliaZagros orogen mixes with quartz-rich recycled sands from Arabia along the western side of the foreland basin, and is traced all along the Gulf shores as far as the Rub' al-Khali sand sea up to 4000 km from Euphrates headwaters.Reviewer #1: This is an excellent review of an intriguing complex modern sediment source-to-sink system that has not been studied in a comprehensive manner prior to...

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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 analysis of the sedimentary succession focuses on the three main lithofacies (siliciclastics, carbonates and evaporites). Petrographic, geochemical and scanning electron microscope analysis of these units are presented. We identified a range of carbonate lithotypes: marly, arenaceous (detrital), organic-rich (fossiliferous), dolomitic limestone and dolomite. Dolomitic limestones occur mostly in the lower part of the lower member of the formation, which was deposited in a barred lagoonal environment with high salinity. The presence of peloidal lime-wackestone with bioclasts, particularly in the upper part of the lower member of the formation, may reflect quiet, shallow-water marine conditions with moderate depths and low energy. The bioclastic-peloidal grainstone-packstone microfacies, with a common and diverse fossil assemblage, may reflect high to moderate energy, shallow-water environments. Evaporites comprise the main sediments of the Fatha Formation. Nodular gypsum is the dominant gypsum type, although laminated, thick-bedded, and secondary gypsum (selenite and satin spar) also occur. In the subsurface, anhydrite and halite are the principal minerals.

Petrographic, geochemical, and scanning electron microscope analyses of the sandstone and mudstone units of the Upper Miocene Injana Formation are presented. Furthermore, microprobe analysis for amphiboles, pyroxenes, garnet, and chromian spinels as common heavy mineral species present is done to support other results for better understanding of the provenance history of the Injana Formation. The sandstones of the Injana Formation consist of terrigenous carbonate lithic fragments as common type of sedimentary rock fragments in addition to chert, argillaceous, and rare sandstone fragments. They also include metamorphic and igneous lithic fragments, quartz, feldspars, and mica and generally, the sandstones are lithic arenites and immature. Scanning electron microscopic analysis for the heavy minerals shows that they have been affected by dissolution due to chemical etching and mechanical abrasion through several surface texture generated either in arid and semihumid environment or in diagenetic environment. Clay mineralogy of the mudstone units indicates the presence of illite, chlorite, kaolinite, palygorskite, and illite-smectite mixed layers. Bulk-rock and mineral phase geochemistry in addition to petrographic data suggest the derivation of the Injana Formation from a nearby sources with contribution from igneous, metamorphic, and sedimentary provenance mainly from the high lands in the northeastern parts of Iraq which comprise mainly the Zagros mountains and the older sedimentary formations.

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 conformablyunderlying 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.

Facies associations and depositional environments of the Late Devonian-Early Carboniferous succession in Iraq have been studied in several boreholes from north and northwestern Iraq. The >400 m-thick succession comprises the Kaista, Ora, Harur and Raha formations which are composed generally of mixed siliciclastic-carbonate facies. The Kaista Formation consists of sandstones intercalated with siltstones and calcareous shale that were deposited in a mixed fluvial-marine environment. The Ora Formation is composed dominantly of black shale with subordinate sandstone and dolomite deposited in a shallow-marine, sub-tidal shelf environment. The Harur Formation is composed mainly of dolomite with subordinate shale and was deposited in a deep sub-tidal environment. The Raha Formation consists mainly of marine shales intercalated with sandstones and concluded the Kaskaskia megasequence. The depositional setting is considered as a subsiding basin with a wide geographic distribution. It extended from the Ora region in the extreme north of Iraq to west and southwestern Iraq and reflects an epicontinental or epeiric sea setting on a homoclinal ramp inclined to the southeast.

The study integrates mineralogical and chemical characteristics of the chromian spinels from northern Iraq using standard petrographic and scanning microscope techniques as well as electron microprobe analyses in order to better understand their provenance, and the implications thereof. Detrital chromian spinels are found as one of the predominant accessory heavy minerals within fluviatile Miocene and Holocene sediments. In addition, such spinels are also present in the Palaeogene-Neogene and Cretaceous alluvial, deltaic and turbiditic sandstones. The results indicate that most of the chromian spinels have interrelated ranges of Cr/(Cr+Al) at rather low contents of Fe and Ti suggesting that the sandstones which host the chromian spinels were derived from a source area dominated by ultramafic rocks. Mineralogical and chemical data suggest that Alpine-type peridotites were the main source rocks for the studied chromian spinels. All available evidence supports the idea that the sandstones originated from the ophiolite-radiolarite belt of the Taurus Range in northeastern Turkey, as well as from recycling of the uplifted Cretaceous strata of northern Iraq.