Paleoecology of Albian – Santonian succession of Surdash to Shaqlawa area, NE Iraq (original) (raw)
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Biostratigraphy of Albian Santonian Succession Along Surdash to Shaqlawa Areas NE Iraq
Iraqi Bulletin of Geology and Mining, 2015
Three formations were studied along Surdash, Qallat, Khalakan, Hezob, Sektan, Degala and Shaqlawa areas in the Sulaimaniyah and Erbil governorates, NE Iraq. These are: Dokan, Gulneri and Kometan formations. The age of these formations are determined depending on the biozones of planktonic foraminifera, and the contact between each two formations was discriminated in the field and by microfossils content. Eleven biozones were distinguished from Albian - Santonian age and at least two biozones up to seven biozones can be discriminated in each section along the study area. Forty-nine species belong to twenty-four genera were used as species of biozones and coeval fossils support each zone .
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 facies analysis of the Cenomanian –Turonian succession of Surdash –Shaqlawa area, NE. Iraq
Iraqi Journal of Science, 2015
Three formations were studied from seven outcrops extend from Surdash to Shaqlawa (Cenomanian – Santonian), they comprise Dokan, Gulneri and Kometan Formations. Four microfacies and eight submicrfacies are identified depending on this microfacies, we determine the depositional environments. Dokan Formation is deposited in open-marine deep shelf environment; it could be deposited at deeper shelf to slope and basinal settings. While Gulneri Formation deposited in open sea shelf, as well as at outer shelf settings, the sediments consist of organic–carbon rich black shale and consider a record of the ocean anoxic event 2, Kometan Formation represent pelagic sediments characterize the deep-marine basins in open marine.
Iraqi Journal of Science
Age and paleoenvironment of part of the Damlouk Member, Ratga Formation from a surface section in the Iraqi Western Desert are investigated. Twenty-nine species of Larger Benthic Foraminifera (LBF) belonging to 13 genera are recognized from the studied section. The LBF assemblage is dominated by the following groups, Nummulites, Alveolina, Rotalia, and Lockhartia. Two species of corals with fragments of bryozoan, red algae and mollusca had also been identified. The palaeontological investigation aimed at identification of LBF assemblages to evaluate their abundance and distribution with respect to sedimentary environment and to determine its age. Based on the recognized Larger Benthic Foraminifera of the studied part of the Damlouk Member, it is subdivided into two biozones: Nummulites gizhensis -Nummulites moculatus Assemblage Zone and Assilina spira- Lokharatia hunti Concurrent Range Zone. Both biozones suggest a Middle - Late Lutetian to Early Bartonian age. The LBF ...
Journal of Oil and Gas Research Reviews, 2023
A moderately diverse larger foraminiferal is described from the NE Iraq, Baba Formation with important stratigraphy, paleontology, microfacies, and palaeoenvironment implications. The fauna is dominated by hyaline perforated and porcellaneous forms including Nummulites, Austrotrillina, Amphistegina, Archaias, Lepidocyclina, Spiroclypeus, Operculina, and Neorotalia. The presence of those fossils allows the age of the formation to be determined as Late Rupelian [Shallow Benthic Zone SBZ 22A]-Early Chattian [Shallow Benthic Zone SBZ 22B], based on the two recognized biozones from older to younger:-Nummulites fichteli-Nummulites intermedius biozone and Lepidocyclina [Eulephidina] dilatata-Nummulites intermedius-Nummulites fichteli biozone. The identified benthic foraminifera were used to recognize three microfacies types: Nummulitic wackestone facies of inner-shelf environment, Nummulitic wackestone-packstone facies of middle-shelf environment, and Epicyclical packstone facies of outer-shelf environment. The palaeoenvironmental setting of the Baba Formation is interpreted as a shallow ramp lagoon environment rich in nutrients, slightly hyper-saline with the shallowest part of the photic zone characterized by the genera Archaias and Austrotrillina, the deeper part of the inner ramp with Nummulites, to the shallow part of the middle ramp with Spiroclypeus and Operculina, to deeper middle ramp setting dominated by coralline rhodoliths along with Lepidocylinids. Microfossils from Baranan and Kurdamir sections have been used for the regional correlations from Eocene-Early Miocene.
Iraqi Bulletin of Geology and Mining, 2011
The studied area is located within the High Folded Zone in Dokan area, northeastern Iraq. The Cretaceous/ Paleogene boundary consists of flysch clastic beds of Tanjero and Kolosh formations, interbedded with marl. The study is achieved on the outcrops of the uppermost part of the Late Cretaceous successions (upper part of Tanjero Formation) and the Early Paleogene (lowermost part of Kolosh Formation). Based on identified planktonic foraminiferal assemblages, five biozones were recorded from the upper part of the Tanjero Formation, these zones are from bottom to top: Pseudotextularia intermedia Interval Zone (CF5), Racemiguembelina fructicosa Interval Zone (CF4), Pseudoguembelina hariaensis Interval Zone (CF3), Pseudoguembelina palpebra Interval Zone (CF2), Plummerita hantkeninoides Total Range Zone (CF1) and two biozones were recorded from the lower part of Kolosh Formation, which are: (P1a) Parvularugoglobigerina eugubina-Subbotina triloculinoides Interval Zone and (P1b) Subbotina triloculinoides-Globanomalina compressa/ Praemurica inconstans Interval Zone. The result of the present study (in contrast to previous studies) shows that the Early Danian is found for the first time in the sediments of the Kolosh Formation. It is possible that the other two zones: P 0 (Guembelitria cretacea Zone), and Pα (Parvularugoglobigerina eugubina Zone) were not recorded completely or continuously in the studied area. The biostratigraphic correlations; based on planktonic foraminiferal zonations showed a comparison between the biostratigraphic zones, which were established in this study with other equivalents of the commonly used planktonic zonal scheme around the Cretaceous/ Paleogene boundary, in and outside Iraq.
Biostratigraphy of the Upper Cretaceous for selected sections in northern Iraq
2019
The Aqra - Bekhme, Shiranish, Tanjero and Kolosh formations outcrop in the High Folded Zone, Northern Iraq in Erbil and Sulaymaniyah governorates. The formations have been studied at two selected geological sections (Bekhme Gorge and Zarda Bee). In this study, these formations are investigated based on both benthic and planktonic foraminifera. Depending on foraminifer’s investigation, three biozones have been recognized; two biozones are identified in the benthic foraminifera and the third one is identified in the planktonic foraminifera as follow: Siderolites calcitropodes - Orbitoides apiculatus - Omphalocyclus macroporus Assemblage zone. Loftusia morgani range zone. Abathomphalus mayaroensis rangezone.
Iraqi National Journal of Earth Sciences, 2021
The basinal part of the Damlouk Member upper sedimentary cycle of the Ratga Formation exposed in the Qaim area of the Iraqi western desert is examined. The studied section consists of marlstone, marly and phosphatic limestone, and planktic foraminiferarich limestone beds. Detailed study of the planktic foraminiferal assemblages of these rocks revealed the occurrences of (30) species belonging to (11) genera. The stratigraphic distribution of these species permits the recognition of three biozones. These are from the lower to upper part of the section:-Acarinina bullbrooki Zone, (Middle Lutetian), Morozovelloides lehneri Zone, (Late Lutetian), Globigerinatheca semiinvoluta-Hantkenina alabamensis Zone, (Early Bartonian). These zones indicate that the studied section of the Ratga Formation (Damlouk Member) is of Middle-Late Lutetian to Early Bartonian age. These biozones are correlated with different local and regional studies.
Iraqi geological journal, 2022
The Late Cretaceous-Early Paleocene Shiranish and Aliji formations have been studied in three selected wells in Jambur Oil Field (Ja-50, Ja-53, and Ja-67) in Kirkuk, Northeastern Iraq. This study included lithostratigraphy and biostratigraphy. The Late Campanian-Maastrichtian Shiranish Formation consist mainly of thin marly and chalky limestone beds overlain by thin marl beds, with some beds of marly limestone representing an outer shelf basinal environment, the unconformable contact with the above Middle Paleocene-Early Eocene Aliji Formation contain layers of limestone with marly limestone and chalky limestone which represents an outer shelf basinal environment. Five Biozones in the Shiranish Formation were determined which are: 1.Globotruncanita calcarata Range Zone (part). 2.Globotruncanella havanensis Partial Range Zone. 3.Globotruncana aegyptiaca Interval Zone. 4.Gansserina gansseri Interval Zone (Part). 5.Abathomphalus mayaroensis Range Zone. While in Aliji Formation there were two biozones determined which are: 1.Guembelitria Cretacea Partial-Range Zone. 2.Parvularugoglobigerina eugubina Total-Range Zone.
Iraqi Geological Journal, 2024
Biostratigraphy of the Sinjar Formation is investigated in two sections (Dokan and Sinjar) from northeastern and northwestern Iraq, respectively. Two hundred samples from all the limestones and marl that form the main lithological components of the studied sections were collected. The studied limestones and marl are rich in microfossils. Through thin sections, we were able to identify thirty species of benthic foraminifera and fifteen species of other microfossils (coral, algae, mollusca, bryozoa, and echinoids) at Dokan section, and fifty-one species of benthic foraminifera and thirty species of other microfossils at Sinjar section. 3 biozones were distinguished from both sections 1-Biozone A: Kathina sp.-Lockhartia hunti Assemblage zone (SBZ 5) (Dokan section); (Kathina pemavuti-Lockhartia hunti Assemblage zone (Sinjar section), 2-Biozone B: Idalina sinjarica Total Range zone (SBZ 6-7) and 3-Biozone C: Alveolina globosa-Alveolina pasitisilata Concurrent Range Zone (SBZ8-10). These zones indicate the Late Paleocene-Early Eocene age of the Sinjar formation. The biostratigraphic correlations in the studied sections are based on benthic foraminiferal zonations. Showed the correlation comparison between the biostratigraphic zones of the commonly used benthic zonal scheme around the Late Paleocene-Early Eocene in and outside of Iraq. paleoecological studies suggest that the carbonate sedimentation of the Sinjar Formation thrived in 18-25oC, with mesophotic to oligophobic light, under an oligotrophic to mesotrophic middle ramp environment with normal marine to slightly saline and at water depths from 40-80 m. Stable isotopic carbon (δ 13 C) and oxygen (δ 18 O) data revealed generally hot conditions with high productivity during the deposition of the Sinjar Formation accompanied by an abrupt change in paleoenvironmental conditions across the Paleocene-Eocene contact.