Oligosteginid Assemblages of Basinal limestone Succession in Ismael awa Section, kurdistan region, North Iraq (original) (raw)
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IRAQI BULLETIN OF GEOLOGY AND MINING (IBGM)\, 2023
Biostratigraphy and paleoecology of the Anah Formation are investigated for the first time in the Sangaw area, Sulaimania Governorate, Northeastern Iraq. Forty species of larger foraminifera and skeletal fragments of brachiopod, coral, pelycepods (bivalves), gastropods, bryozoan and algae shell, are described in seven samples collected from one section near the Pungala village. Based on the distribution of the larger benthic foraminifera and other skeletal grains, two assemblage biozones of Upper Oligocene (Chattian) age have been recognized. During the Chattian, the carbonate deposits of the Anah Formation in the studied section are mostly composed of coralline red algae and large flat benthic foraminifera. The biotic associations identified in this study suggest that the carbonate sedimentation of the Anah Formation thrived in tropical to subtropical waters under oligotrophic to mesotrophic middle ramp environment with normal seawater salinity to a higher salinity inner ramp setting and at water depths that ranged from 40 to 80 m.
Stratigraphy of the Oligocene-Early Miocene successions, Sangaw area, Kurdistan Region, NE-Iraq
Lithostratigraphy and biostratigraphy of the Darzila section from Low Folded Zone, Ashdagh Mountain, Sangaw area, Kurdistan Region, Northeastern Iraq, is investigated. Forty-three species from twenty-nine genera of large benthic foraminifera (LBF) in addition to non-foraminifera fossils such as echinoid fragments, bryozoan, red algae, green algae, bivalve, and coral are recognized from the studied section. Based on the recognized large benthic foraminifera, it is subdivided into six biozones: Nummulites vascus-Nummulites fichteli Assemblage Zone, Eulepidina dilatata-Nephrolepidina marginata Concurrent-Range Zone, Praerhapydionina delicata-Peneroplis evolutus-Concurrent Range Zone, Meandrospina anahensis-Austrotrillin asmariensis Interval Zone, Ammonia beccarii-Austrotrillina howchini Assemblage Zone, and Dendritina rangi-Rotalia viennoti Assemblage Zone. Both suggest an Oligocene to Early Miocene age. Each of these biozones represents certain lithostratigraphic units, which are Sheikh Alas, Baba, Bajwan, Anah, Jeribe, and Fatha formations. The recognized biozones were correlated with comparatively well-known biozones from other parts of the tethys region which showed a good comparison between the biostratigraphic zones established in this study with other studies.
Springer-Arabian Journal of Geoscience, 2014
Oligocene and Lower Miocene sediments from High Folded Zone of Iraqi Zagros have been studied paleontologically at south of Sulaimaniyah, Kurdistan Region, NE Iraq. The identified fauna are consisted of (25) genera and species of benthonic and (16) species of planktonic foraminifera. The fauna comprises relatively abundant foraminiferal assemblages of moderate diversity. Based on the stratigraphic distribution of these species, two biozones have been recognized which are Nummulites—Rotalia and Globoquadrina dehiscens zones. These biozones indicate that the studied sections of Basara and Khewata are of Late Oligocene–Early Miocene age. Based on the microfossils, it has been found that the age of sediments is equivalent to or represents Anah and Serikagni Formations. Some previous studies described Oligocene rocks (Kirkuk Group) as interior sag basin. In the present study, the occurrence of the group inside High Folded Zone and its rich fauna content are used for the discussion of the sag basin versus normal marine water.
Journal of Applied Material Science & Engineering Research, 2024
Forty-nine samples were collected for a biostratigraphic study of the Naouprdan Formation to determine the age of its strata. The studied section is located within the Zagros High Fold and Thrust Belt, from the Bulfat area, Sulaimaniyah, Kurdistan Region/northeastern Iraq. The lithology of the succession here is composed of grey fine-grain of limestone with Nummulites and Alveoloina, the whole section is highly deformed and fractured. Hence, for the first time, this limestone unit is described in detail; it is a 48 m bed of grey fine-grain, Alveolinidae-Nummulitidae limestone. It bears a frequent number of large benthic foraminifera that are concentrated within the limestone bed. The identified benthic foraminifera are of the groups: Nummulitidae; Alveolinidae; Acervulinidae; Rotaliidae; Linderinidae; Linderinidae; Hauerinidae; Textulariidae; Textulariidae. A detailed study of the microfossil assemblages of the Naouprdan Formation revealed the occurrences of (53) species of benthic foraminifera belonging to (23) genera. The stratigraphic distribution of benthic foraminifera permits the recognition of four biozones. These are from the bottom to the top of the section: Alveolina oblonga-Nummulites djokdjokartae Interval Zone, Nummulites djokdjokartae Total Range Zone, Nummulites fabiani Total Range Zone, and Alveolina leupoldi-Alveolina elliptica Interval Zone. This section is described for the first time.
IRAQI BULLETIN OF GEOLOGY AND MINING (IBGM)\, 2023
Upper Albian and Lower Cenomanian biostratigraphy and microfacies types of the Mauddud Formation from Musaiyib well No.1, Central Iraq are described and examined, which consists of thick to medium bedded limestone, marly limestone rich in argillaceous material, green shale, and dolomitic limestone beds. Thirty-six species from twenty-two genera of benthic foraminifera in addition to calcareous algae, coral, bivalves, gastropods, rudist fragments, brachiopods, bryozoan, and echinoid fragments are recognized from the Mauddud Formation of the studied well. On the basis of the recognized benthic foraminifera three biozones were determined: Mesorbitolina texana-Orbitolina qatarica Concurrent Range zone-Orbitolina sefini-Total R. Zone and Orbtolina concava Total R. Zone. Both suggest the Late Albian-Early Cenomanian age. The results of this study are compared with the work of others inside and outside Iraq. Based on the petrographical analyses, four major microfacies (Mudstone, wackestone, wackestone to packstone, and packstone), and nine sub-microfacies were identified. The Mauddud Formation was formed in a marine environment that was composed of the following three sub-environments: the inner ramp and the middle to the outer ramp.
The age and evolution of paleoenvironmental conditions in the Oligocene (Baba Formation) from the Bai-Hassan Well-4 section were studied from the distribution of Large Benthic Foraminifera (LBF), microfacies, and paleoecology. We identified 30 species from 21 genera of Large Benthic Foraminifera (LBF) in addition to corals and algae with remains of mollusca and echinoid spines, belonging to two assemblage zones which are Nummulites vascus, Nummulites fichteli Assemblage Zone and Lepidocyclina (Eulephidina) dilatata-Nummulites vascus, Nummulites fichteli Assemblage Zone. The Baba Formation spans Late Rupelian-to-Early Chattian age in the studied section. Bai-Hassan Well-4 section was subdivided into three carbonate microfacies from the lower to the upper part: fine-to-very coarse bioclastic larger foraminiferal wackestone-packstone (MF1), fine-to-very coarse bioclastic larger foraminiferal packstone (MF2), and fine-to-coarse bioclastic larger foraminiferal packstone-grainstone (MF3). The main depositional environment of the Baba Formation from the lower to the upper art of the studied section is represented by outer ramp starting from open shelf lagoon, and it was deposited from subtropical to a tropical environment from, the lower part to the middle and the upper part of the studied section, with mesotrophic-to-oligotrophic conditions, open marine to shallow and restricted environments with normal to higher water salinity (34-50 ‰), and mesophotic-to-oligophotic conditions of soft-to-hard sediments.
STRATIGRAPHY OF THE OLIGOCENE – EARLY MIOCENE EXPOSED FORMATIONS IN SINJAR AREA, NW IRAQ
Sinjar Mountain is an outstanding structural and geomorphic feature in the northwestern part of Iraq. It forms a long anticline in which the oldest exposed rocks belong to Cretaceous age represented by Shiranish Formation. The exposed succession includes rocks of many formations, which range from Cretaceous to Late Miocene. The presence of Oligocene rocks, however, has been a matter of debate. The main aim of this study is to prove the presence or otherwise of the Oligocene formations in Sinjar anticline. To achieve that, the planktonic foraminifera of an exposed section, starting from the top of Jaddala Formation (Eocene), were utilized to interpret the biostratigraphy, and zonation of the sections.
J App Mat Sci & Engg Res, 2023
Forty-nine samples were collected for a biostratigraphic study of the Naouprdan Formation to determine the age of its strata. The studied section is located within the Zagros High Fold and Thrust Belt, from the Bulfat area, Sulaimaniyah, Kurdistan Region/northeastern Iraq. The lithology of the succession here is composed of grey fine-grain of limestone with Nummulites and Alveoloina, the whole section is highly deformed and fractured. Hence, for the first time, this limestone unit is described in detail; it is a 48 m bed of grey fine-grain, Alveolinidae-Nummulitidae limestone. It bears a frequent number of large benthic foraminifera that are concentrated within the limestone bed. The identified benthic foraminifera are of the groups: Nummulitidae; Alveolinidae; Acervulinidae; Rotaliidae; Linderinidae; Linderinidae; Hauerinidae; Textulariidae; Textulariidae. A detailed study of the microfossil assemblages of the Naouprdan Formation revealed the occurrences of (53) species of benthic foraminifera belonging to (23) genera. The stratigraphic distribution of benthic foraminifera permits the recognition of four biozones. These are from the bottom to the top of the section: Alveolina oblonga-Nummulites djokdjokartae Interval Zone, Nummulites djokdjokartae Total Range Zone, Nummulites fabiani Total Range Zone, and Alveolina leupoldi-Alveolina elliptica Interval Zone. This section is described for the first time.
Iraqi Geological Journal, 2021
Biostratigraphical and sedimentological study of the Sarmord Formation (Upper Valanginian - Upper Hauterivian) at the southern limb of Maten anticline is conducted within a well-exposed section. The formation is composed of marl, marly limestone, limestone, and dolostone, which yielded moderately diversified benthonic foraminiferal fauna, green algae, echinoderms, gastropods and some bioclast. The stratigraphic distribution of the benthonic species permits the recognition of two well-defined biozones. These are Everticyclammina kelleri Assemblage Zone, which represents the Late Valanginian age and Pseudocyclammina lituus Assemblage Zone, indicating Hauterivian age. These larger benthonic foraminiferal biozones are correlated with other zonal schemes inside and outside of Iraq, which indicates that the age of the Sarmord Formation in Maten anticline extends from Late Valanginian to Late Hauterivian age. The Sarmord Formation in the studied section is composed of limestone, dolomite, ...
المجلة العراقية الوطنية لعلوم الارض, 2018
The biostratigraphy of Balambo Formation has been investigated within a well-exposed section at the northeastern limb of Zozik anticline, near Barsarin Village, northeastern Iraq. The studied section consists mainly of marl, marly limestone and limestone. These rocks yielded moderately diversified planktonic foraminiferal fauna and radiolarian skeletons, in addition to some benthonic foraminifera and bioclast. The study is focusing on planktonic foraminiferal taxa, which are classified to ten species belonging to three genera. the stratigraphic distribution of the recorded species permits the recognition of five well defined biozones. These are in descending order:. Globigerinelloides algeriana Taxon range Zone. (part). Globigerinelloides ferreolensis Interval Zone.. Globigerinelloides blowi Interval Zone.. Hedbergella sigali Interval Zone.. Globuligerina hoterivica Interval Zone. The planktonic foraminiferal biozones are correlated with other zonal schemes. They are considered to be extending from Late Valanginian to Late Aptian age.