Stratigraphic and Microfacies Study of Kometan Formation (Upper Turonian-Lower Campanian), in the Dokan area, Northern Iraq

The Kometan Formation is widely distributed in the northern (Kurdistan region) and central Iraq. The studied area is located near the Dokan Dam, about 58 km., to the Northwest of the Sulaymaniyah city, Northeastern Iraq. The Kometan Formation is exposed on the southwest flank of the Sarah anticline. The formation consists of limestone and dolomitic limestone, which have cherts nodules throughout the formation. The Gulneri Formation is recorded below the Kometan Formation with unconformable contact, while at the top is bounded by the Shiranish Formation unconformably too. Three microfacies are identified, these are lime mudstone, planktic foraminiferal lime wackestone-packstone, keeld planktonic foraminiferal lime wackestone-packstone microfacies. All the sedimentary and fossil evidence refer that the sedimentary environment of the formation is the outer shelf to upper bathyal at the lower and upper parts of formation and its extension to the middle bathyal in the middle part of the formation. Based on the stratigraphic ranges of the recorded Calcareous nannofossils biozones, the age of the Kometan Formation at Dokan area is Late Turonian-Early Campanian.

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Lithostratigraphy and microfacies analysis of Avanah Formation (Middle Eocene) in Gomaspan section northeast Erbil City, Kurdistan region, Iraq

Kuwait Journal of Science ◽

10.48129/kjs.11833 ◽

2021 ◽

Author(s):

Irfan Sh. Asaad ◽

Keyword(s):

Middle Eocene ◽

Planktonic Foraminifera ◽

Middle Part ◽

Petrographic Analysis ◽

Microfacies Analysis ◽

Dolomitic Limestone ◽

Kurdistan Region ◽

Thin Sections ◽

Lithostratigraphic Units ◽

Lagoon Environment

Lithostratigraphy and microfacies analysis of the Avanah Formation (Middle Eocene) were studied in the Gomaspan section in the Bina Bawi anticline, northeast of Erbil city, Kurdistan Region, Iraq. The field observations refer that the formation attains 56 m of medium to thick bedded yellow limestone, grey dolomitic limestone and blue marly dolomitic limestone interbedded with thin beds of blue marl and dark grey shale with an interval of sandy limestone in the middle part and thin to medium bedded limestone interbedded with red mudstone. The petrographic study of 29 thin sections of Avanah carbonates revealed that the majority of the matrix is carbonate mud (micrite) with few microspar. The skeletal grains include benthic foraminifera, dasycladacean green algae, ostracods, calcispheres, pelecypods, rare planktonic foraminifera and bryozoa in addition to bioclasts. Non-skeletal grains encompass peloids, oncoids, intraclasts and extraclasts with common monocrystalline quartz. Based on the field observation and petrographic analysis, three different lithostratigraphic units were identified. They are in ascending order: A-Thick bedded dolomitic marly limestone interbedded with shale. B- Bedded dolomitic limestone interbedded with shale and marl. C- Thin to medium bedded limestone interbedded with red mudstone. Depending on detailed microfacies analysis of carbonate rocks, three main microfacies and 12 submicrofacies are recognized. From the sum of all petrographic, facies, textural analyses, it is concluded that Avanah Formation in Gomaspan section, was deposited in shallow marine environment, semi restricted lagoon, in lower and upper parts and open lagoon environment in the middle part interval.

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Cretaceous (Aptian-Maastrichtian) stratigraphy of the Shiranish Islam area, northern Iraq

Stratigraphy ◽

10.29041/strat.18.1.02 ◽

2021 ◽

pp. 29-70

Author(s):

Stephen R. Packer ◽

Kathryn L. Canner ◽

Ali Chalabi

Keyword(s):

Analytical Data ◽

Middle Part ◽

Kurdistan Region ◽

Clastic Material ◽

Larger Benthic Foraminifera ◽

Shallow Marine ◽

Northern Iraq ◽

Faunal Succession ◽

World Class ◽

Early Late

ABSTRACT: The Kurdistan region of northern Iraq contains world-class outcrops that make it possible to examine the Cretaceous deep and shallow marine Tethyan faunal succession. Six separate sections covering the Shiranish, Bekhme, Mergi and Qamchuqa formations have been investigated in this study from the Shiranish Islam area. A number of papers have been published on this area, but no comprehensive biostratigraphic record has been published that fully documents the Cretaceous stratigraphy and the chronostratigraphic interpretation of the succession. As a result, this has led to significant lithostratigraphic and chronostratigraphic uncertainties. The upper part of the Qamchuqa is pervasively dolomitized. Rare occurrences of foraminifera are found in less dolomitized intervals in thin-section indicating an early - middle Albian age for the top of the formation. A thin interval comprising the Gir Bir Formation is Cenomanian in age and is present between the top of the Qamchuqa Formation and the overlying conglomerate. Historical studies indicate that the Turonian Mergi Formation occurs between the Qamchuqa and Bekhme formations, but our field and analytical data does not support it as a discrete lithostratigraphic entity, as Turonian aged faunas were not recognized. The conglomerate separating the top of the Gir Bir and base of the Bekhme is subdivided into three units (A, B & C). Units A and B are late Cenomanian to early Turonian age, whilst Unit C is of Campanian age. A significant hiatus separates the Gir Bir and the Bekhme, which encompasses the intra Turonian to Santonian. The limestone facies of the lower part of the Bekhme Formation contains rich benthic foraminiferal faunas (miliolids, Pseudedomia, Cuneolina) of early - early middle Campanian age. This lower - lower middle Campanian section at Shiranish Islam is considered to be equivalent of the upper part of the Sa'di Formation in central Iraq and is therefore re-assigned on the basis of chronostratigraphic attribution to the Sa'di (equivalent) herein. The top of the early - early middle Campanian biofacies is abruptly truncated by an omission surface, marked by an erosive base, an influx of clastic material and a major up-section biofacies change characterized by an influx of Pseudosiderolites and Orbitoides representing an intra-Campanian hiatus. The bioevent sequence suggests that this hiatus at Shiranish Islam comprises at least the middle Campanian (upper part of the G. elevata Zone) into the late Campanian (intra R. calcarata Zone), from approximately 80.64 Ma to 76.09 Ma with 4.55 my missing. The middle part of the Bekhme Formation comprising the Pseudosiderolites - Orbitoides facies is thin (c. three meters) and is re-assigned to the Lower Bekhme Member. The boundary between the Lower Bekhme Member and the Upper Bekhme Member is conformable and marked by a gradual up-section reduction in the size and presence of larger benthic foraminifera (Orbitoides, Pseudosiderolites) and an increase in the planktic component (small planktics and calcispheres). This trend of gradually increasing water depth continues into the Shiranish Formation, with no apparent major breaks in deposition. The Campanian - Maastrichtian boundary falls within Unit A of the Shiranish Formation. Deposition of the Shiranish continued into the earliest late Maastrichtian and is unconformably overlain by the Danian Kolosh Formation. The hiatus between the top of the Cretaceous and the Paleocene extends from the early late Maastrichtian (c. 68.86 Ma) to the upper part of the Danian (62.2 Ma) with an estimated duration of 6.66 my.

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Stratigraphic And Microfacies Study Of Upper Campanian - Lower Maastrichtian Succession (Shiranish Formation) In Bade Village, Bekhere Anticline, Kurdistan Region, Northern Iraq

Bulletin of the Geological Society of Malaysia ◽

10.7186/bgsm71202104 ◽

2021 ◽

Vol 71 ◽

pp. 47-55

Author(s):

Zaid A. Malak ◽

◽

Omar A. Al-Badrani ◽

Ezzat I. Al-Fandi

Keyword(s):

Planktonic Foraminifera ◽

Calcareous Nannofossils ◽

Kurdistan Region ◽

Planktic Foraminifera ◽

Thin Sections ◽

Northern Iraq ◽

Lower Maastrichtian ◽

Marly Limestone ◽

Quartz Grains ◽

Upper Campanian

The Upper Cretaceous Shiranish Formation outcropped close to Bade village and Bekhere anticline, Kurdistan region at northern Iraq and consists of alternating mixed tough grey limestone, marly limestone, marl beds interpreted as a middle - outer shelf – upper bathyal environments (basinal) depositional environment. Fifteen thin sections were studied under a polarized microscope to find out the petrographic component, fauna content, and for microfacies analysis. The major petrographic constituents are fossils, bioclastic grains, micrite matrix, and extraclast (quartz grains). Planktic foraminifera and nannofossils are the major particles within wackestone and packstone microfacies types. The planktonic foraminifera biozones from previous study (such as Globotruncana aegyptiaca, Gansserina gansseri, Racemiguembelina fructicosa, Plummerita hantkeninoides) and the recorded calcareous nannofossils biozones of Broinsonia parca, Reinhardtites levis, Arkhangelskiella cymbiformis, suggest a late Campanian to late Maastrichtian age.

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Calcareous Nannofossil Biostratigraphy and Ostracoda Paleoecology of Hartha Formation from Balad (1) well, Central Iraq

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.11.17 ◽

2021 ◽

pp. 3962-3972

Author(s):

Omar Ahmed Al-Badrani ◽

Faris Nejris Hassan ◽

Mahfoudh Abdulla Al-Hadeedy

Keyword(s):

Continental Shelf ◽

Outer Shelf ◽

Calcareous Nannofossils ◽

Calcareous Nannofossil ◽

Inner Shelf ◽

Calcareous Nannofossil Biostratigraphy ◽

Stratigraphic Ranges

Seventeen samples of Hartha Formation in Balad (1) well, central Iraq, are studied on the basis of stratigraphic ranges of the recorded calcareous nannofossils for twenty species belonging to twelve genera. The studied section reveals three biozones arranged from oldest to youngest as follows; (1) Calculites ovalis Interval Biozone (CC19), (2) Ceratolithoides aculeus Interval Biozone (CC20), (3) Quadrum sissinghii Interval Biozone (CC21). These Biozones are correlated with other calcareous nannofossils biozones from both local and regional sections, leading to conclude the age of the Middle Campanian. Rerecorded eighteen ostracode species that belong to eleven genera are identified, all of which were previously recorded from Iraq and adjacent regions. The occurrence of these species leads to conclude a continental shelf environment, while they are typical of inner shelf-outer shelf depth.

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Lithostratigraphy and microfacies analysis of Avanah Formation (Middle Eocene) in Gomaspan section northeast Erbil City, Kurdistan region, Iraq

Kuwait Journal of Science ◽

10.48129/kjs.11183 ◽

2021 ◽

Author(s):

Irfan Sh. Asaad ◽

Keyword(s):

Middle Eocene ◽

Planktonic Foraminifera ◽

Middle Part ◽

Petrographic Analysis ◽

Microfacies Analysis ◽

Dolomitic Limestone ◽

Kurdistan Region ◽

Thin Sections ◽

Lithostratigraphic Units ◽

Lagoon Environment

Lithostratigraphy and microfacies analysis of the Avanah Formation (Middle Eocene) were studied in the Gomaspan section in the Bina Bawi anticline, northeast of Erbil city, Kurdistan Region, Iraq. The field observations refer that the formation attains 56 m of medium to thick bedded yellow limestone, grey dolomitic limestone and blue marly dolomitic limestone interbedded with thin beds of blue marl and dark grey shale with an interval of sandy limestone in the middle part and thin to medium bedded limestone interbedded with red mudstone. The petrographic study of 29 thin sections of Avanah carbonates revealed that the majority of the matrix is carbonate mud (micrite) with few microspar. The skeletal grains include benthic foraminifera, dasycladacean green algae, ostracods, calcispheres, pelecypods, rare planktonic foraminifera and bryozoa in addition to bioclasts. Non-skeletal grains encompass peloids, oncoids, intraclasts and extraclasts with common monocrystalline quartz. Based on the field observation and petrographic analysis, three different lithostratigraphic units were identified. They are in ascending order: A-Thick bedded dolomitic marly limestone interbedded with shale. B- Bedded interbedded with red mudstone. Depending on detailed microfacies analysis of carbonate rocks, three main microfacies and 12 submicrofacies are recognized. From the sum of all petrographic, facies, textural analyses, it is concluded that Avanah Formation in Gomaspan section, was deposited in shallow marine environment, semi restricted lagoon, in lower and upper parts and open lagoon environment in the middle part interval.

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THE LATER PREHISTORY OF THE SHAHRIZOR PLAIN, KURDISTAN REGION OF IRAQ: FURTHER INVESTIGATIONS AT GURGA CHIYA AND TEPE MARANI

Iraq ◽

10.1017/irq.2020.3 ◽

2020 ◽

Vol 82 ◽

pp. 41-71

Author(s):

Robert Carter ◽

David Wengrow ◽

Saber Ahmed Saber ◽

Sami Jamil Hamarashi ◽

Mary Shepperson ◽

...

Keyword(s):

Material Culture ◽

Environmental Data ◽

Kurdistan Region ◽

Ceramic Assemblage ◽

Radiocarbon Dates ◽

Northern Iraq ◽

Halaf Period ◽

Adjacent Site ◽

Related Series ◽

Southern Iraq

The Shahrizor Prehistory Project has targeted prehistoric levels of the Late Ubaid and Late Chalcolithic 4 (LC4; Late Middle Uruk) periods at Gurga Chiya (Shahrizor, Kurdistan region of northern Iraq), along with the Halaf period at the adjacent site of Tepe Marani. Excavations at the latter have produced new dietary and environmental data for the sixth millennium B.C. in the region, while at Gurga Chiya part of a burned Late Ubaid tripartite house was excavated. This has yielded a promising archaeobotanical assemblage and established a benchmark ceramic assemblage for the Shahrizor Plain, which is closely comparable to material known from Tell Madhhur in the Hamrin valley. The related series of radiocarbon dates gives significant new insights into the divergent timing of the Late Ubaid and early LC in northern and southern Mesopotamia. In the following occupation horizon, a ceramic assemblage closely aligned to the southern Middle Uruk indicates convergence of material culture with central and southern Iraq as early as the LC4 period. Combined with data for the appearance of Early Uruk elements at sites in the adjacent Qara Dagh region, this hints at long-term co-development of material culture during the fourth millennium B.C. in southeastern Iraqi Kurdistan and central and southern Iraq, potentially questioning the model of expansion or colonialism from the south.

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