scholarly journals Biostratigraphy and Sequence Stratigraphy of Paleogene Deposits in Central Kopet-Dagh Basin (NE of Iran)

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Batool Rivandi ◽  
Mohammad Vahidinia ◽  
Mehdi Nadjafi ◽  
Asadollah Mahboubi ◽  
Abbas Sadeghi
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Planktonic Foraminifera ◽  
Larger Benthic Foraminifera ◽  
Sequence Stratigraphic ◽  
Kopet Dagh ◽  
Sudden Decrease ◽  
Shallow Carbonate Platform

In this paper, the biostratigraphy and sequence stratigraphy of marine Paleogene deposits from the Kopet-Dagh basin (NE of Iran) are described. Particularly the absence of Morozovella genus is discussed. In addition, the Paleocene/Eocene boundary has been studied in detail using the record of planktonic and larger benthic foraminifera. This boundary is located probably within a thin red horizon (~10–15 cm) representing a paleosoil. Close to this boundary is located the base of the calcareous test dissolution interval, with the dominance of agglutinated benthic foraminifera and with a sudden decrease in the richness of benthic foraminiferal species. Biostratigraphic studies led to the identification of 33 genera of larger benthic foraminifera and 5 genera of planktonic foraminifera. Petrographical studies indicate that these sediments, consisting of four carbonate lithofacies (15 subfacies), may have been deposited on a shallow carbonate platform (ramp type). These lithofacies have been deposited in open marine, shoal, lagoon, and tidal flat environmental conditions. Sequence stratigraphic analysis led to the identification of four third-order depositional sequences. The interpreted sea-level curve in the Kopet-Dagh basin can be correlated with Paleocene-Eocene global curves, with a sea-level fall in the latest Paleocene, followed by a sea-level rise in the earliest Eocene.

scholarly journals Bio-Sequence Stratigraphy of Asmari Formation in the Southeast of Norabad (Zagros Basin, SW Iran)

2021 ◽  
Author(s):  
Mohammadsadegh Dehghanian
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Carbonate Platform ◽  
Reservoir Rock ◽  
Dispersion Pattern ◽  
Asmari Formation ◽  
Level Curve ◽  
Zagros Basin ◽  
Lithostratigraphic Units ◽  
Global Sea Level

Abstract Asmari Formation is the thick sequence of carbonate sediment in the range of Oligocene-Miocene which is deposited in the foreland basins of the Zagros and is considered as the original and most famous reservoir rock of Zagros basin. To study of lithostratigraphic units and sequence stratigraphy of this Formation, the section in the southeast of Norabad was selected. Field study indicated that Asmari Formation possessed the thickness of 401.5m and included 9 lithostratigraphic units. According to the study of microfacies, Stacking pattern and identification of main sequence level, three depositional sequences including two-second order and one-third order sequence were recognized. The sea-level curve in the studied section indicated that it was correspondence to the global sea level curve. These facies deposited in five environmental sedimentations as follow Open Sea Shelf (Fore Barrier), Bar, Lagoon, Back bar shelf, and Shoal. The environment is part of a carbonate platform that has been formed on an open shelf. In addition, according to the Study of foraminifer dispersion pattern the range of Asmari Formation in Norabad was suggested to be Oligocene (Rupelian- Chattian) to lower Miocene (Aquitanian- Burdigalian).

scholarly journals Stratigraphy and Sedimentology of Upper Cretaceous to Upper Palaeocene Succession in Zimam Formation Along Wadi Tar al Kabir, NW Libya

2020 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Esam O. Abdulsamad ◽  
Saleh A. Emhanna ◽  
Muayid B. Asmaeil ◽  
Ahmed A. Alwddani ◽  
Fuad M. Rasheed ◽  
...  
Keyword(s):  
Benthic Foraminifera ◽  
Upper Cretaceous ◽  
Planktonic Foraminifera ◽  
Sedimentary Facies ◽  
Larger Benthic Foraminifera ◽  
Sedimentary Cycles ◽  
Total Range ◽  
Field Investigations ◽  
Sedimentary Cycle ◽  
Nw Libya

The Upper Cretaceous to Upper Palaeocene rocks of the Zimam Formation along the southwestern escarpment of the Hun Graben of NW Libya have been stratigraphically investigated from two stratigraphical sections in wadi Tar al Kabir. The field investigations led to the recognition of three members, from the oldest to the youngest, the Lower Tar Member, the Upper Tar Member and the Had Member. Eight sedimentary facies were distinguished at outcrop-scale and several microfacies were recognized and the outcome indicates that the depositions of the Zimam Formation are corresponding to two transgressive-regressive sedimentary cycles. The first cycle is attributed to the Lower Tar Member in which small planktonic foraminifera is quite common in the Campanian whereas the larger benthic foraminifera, namely, Omphalocyclus macroporus and Siderolites calcitrapoides are abundant in the Maastrichtian. The last occurrence of the latter two taxa, however, was used to delineate the contact between the Maastrichtian and Danian stages in the studied sequence. Up-sequence the sediments of the Upper Tar Member along with the overlying Had Member correspond to the second transgressive-regressive sedimentary cycle. Herein, the Upper Tar Member is enriched by small benthic foraminifera; Neoeponides duwi and Cibicides cf. libycus, and has been ascribed to the Danian (Lower Palaeocene). The reaming sediments of Zimam Formation, however, are belonging to the overlying Had Member and is tentatively ascribed to the Selandian (Upper Palaeocene) based on the last occurrence of the Danian fauna and the total range of the codiacean algae Ovulites morelleti.

scholarly journals FIRST RECORD OF CALCAREOUS GREEN ALGAE (DASYCLADALES, HALIMEDACEAE) FROM THE PALEOCENE CHEHEL KAMAN FORMATION OF NORTH-EASTERN IRAN (KOPET-DAGH BASIN)

2021 ◽  
pp. 51-64
Author(s):  
FELIX SCHLAGINTWEIT ◽  
KOOROSH RASHIDI ◽  
ABDOLMAJID MOSAVINIA
Keyword(s):  
Shallow Water ◽  
Green Algae ◽  
Benthic Foraminifera ◽  
First Record ◽  
Larger Benthic Foraminifera ◽  
Eastern Iran ◽  
North Eastern ◽  
Kopet Dagh ◽  
First Time ◽  
Upper Paleocene

The micropalaeontological inventory of the shallow-water carbonates of the Paleocene Chehel-Kaman Formation cropping out in the Kopet-Dagh Basin of north-eastern Iran is poorly known. New sampling has evidenced for the first time the occurrence of layers with abundant calcareous green algae including Dasycladales and Halimedaceae. The following dasycladalean taxa have been observed: Jodotella veslensis Morellet & Morellet, Cymopolia cf. mayaense Johnson & Kaska, Neomeris plagnensis Deloffre, Thyrsoporella-Trinocladus, Uteria aff. merienda (Elliott) and Acicularia div. sp. The studied section is devoid of larger benthic foraminifera and can be referred to the middle-upper Paleocene (SBZ 2-4) due to the presence of Rahaghia khorassanica (Rahaghi). Some of the dasycladalean taxa are herein reported for the first time not only from Iran but also the Central Neotethyan realm.

The incidence of unusual test morphologies of Eocene Larger benthic foraminifera: An example of Paleogene Adriatic Carbonate Platform

2021 ◽  
Author(s):  
Vlasta Ćosović ◽  
Jelena Španiček ◽  
Katica Drobne ◽  
Ervin Mrinjek
Keyword(s):  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Middle Eocene ◽  
Morphological Diversity ◽  
Late Eocene ◽  
Early Eocene ◽  
Coralline Red Algae ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Scientific Project

<p>The Paleogene Adriatic carbonate platform(s) existed within the Central NeoTethys (around 32 N paleolatitude) from the Danian to the late Eocene (Bartonian/Priabonian) and produced a succession of limestones up to 500 m thick, rich in larger benthic foraminifera (LBF). The Eocene sediments are widely distributed along the eastern Adriatic coast and have been studied for many years. Taking into account the climatic changes that took place within the Eocene (Early Eocene and Middle Eocene climatic optima, known as EECO, MECO), special attention was paid to the composition of shallow-marine foraminiferal assemblages. The studies reveal the following trends: (1) the alveolinid-dominated assemblages were replaced by nummulitid-dominated assemblages around the MECO; (2) the greater species and morphological diversity (spherical, ellipsoid, extremely elongated fusiform) of the alveolinid fauna was evident at the EECO; (3) the nummulitid-dominated fauna was characterized by less diversified assemblages compared to the alveolinid ones and by the co-occurrence of scleractinian corals, coralline red algae and aborescent foraminifera. The occurrence of twin embryos has been assigned to the early Eocene in the alveolinid populations, especially in Alveolina levantina and A. axiampla (in some sections, the frequency is greater than 5%), and these coalesced embryos have the same size as the single form (usually they are smaller). The LBF assemblages of Middle Eocene showed a greater frequency of doubled adult tests (Orbitolites sp., Nummulites sp.). The origin of these unusual morphologies is poorly known, usually described as the results of stressful conditions. Considering the timing of the appearance of such morphologies, temperature and associated changes in the shallow-marine environment could be the cause.</p><p>This study is carried out as part of the scientific project IP-2019-04-5775 BREEMECO, funded by Croatian Scientific Foundation.</p>

Cenozoic Benthic Foraminifera Case Histories of Paleoceanographic and Sea-Level Changes

1982 ◽  
Vol 6 ◽  
pp. 107-126 ◽  
Author(s):  
Kenneth G. Miller
Keyword(s):  
Sea Level ◽  
Benthic Foraminifera ◽  
Deep Sea ◽  
Planktonic Foraminifera ◽  
Environmental Studies ◽  
Sea Level Changes ◽  
Case Histories ◽  
Reasonable Degree ◽  
Near Future ◽  
And Sea Level

Since the inception of their use in commercial micropaleontology, benthic foraminifera have proven to be eminently useful in the solution of geological problems. The utilitarian credentials of benthic foraminifera in estimating paleodepths from marsh through neritic environments with a reasonable degree of accuracy and to indicate approximate ages (viz. subdivision of series/epochs) have been established in both commercial and academic applications. Benthic foraminifera are generally more resistant to dissolution than planktonic foraminifera, and have wide distributions; many taxa have restricted stratlgraphic ranges, making them suitable for correlation and paleo-environmental studies. Yet, three problems have tended to limit the utility of benthic foraminifera: 1) there is a lack of uniformity in taxonomy (Boltovskoy, 1980; Douglas & Woodruff, 1982); 2) attempts to erect zonal schemes using benthic foraminifera have resulted in boundaries which are later proven to be diachronous relative to planktonic zonatlons (e.g. the California provincial stages, Poore, 1976); and 3) attempts to interpret paleodepths from deep-sea benthic foraminifera have produced widely-varying results. One could perhaps conclude, as Boltovskoy (1965a) did over a decade ago, that these problems indicate “…the near future of this science is rather bleak.”

Benthic foraminifera from the Albian shallow-marine limestones in the Geyik Dağı area (Central Taurides), southern Turkey

2021 ◽  
pp. 1-21
Author(s):  
Cemile Solak ◽  
Kemal Taslı ◽  
Hayati Koç
Keyword(s):  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Southern Turkey ◽  
Lowermost Part ◽  
First Time ◽  
High Diversity ◽  
Open Shelf

Abstract Cretaceous carbonates in the Geyik Dağı area (Central Taurides, southern Turkey) are represented by two successions with different paleoenvironmental settings: open shelf to slope succession of Cenomanian to Danian age and inner platform succession of Albian to Maastrichtian age, which is interrupted by a post-Cenomanian disconformity. Outcropped lowermost part of the platform-type one is composed of rudistid limestones corresponding to the Urgonian-type carbonates and belongs to the Geyik Dağı Unit (=Anamas-Akseki Carbonate Platform). It contains a rich assemblage of larger benthic foraminifera including orbitolinid, chrysalidinid, cuneolinid, nezzazatid, and miliolid taxa, which has been illustrated and documented here for the first time from the upper Albian of the Tauride Carbonate Platform. The occurrence of such a diversified foraminiferal fauna indicates a prominent high diversity that took place in the Tauride Carbonate Platform during the late Albian time, which corresponds to a major emersion period in some parts of the platform.

Sign in / Sign up

Export Citation Format

Share Document