Estimation of Species Richness of Permian Foraminifera in Non-Parametric Methods and Investigation of Its Change Trend in Central Alborz, Western Tethys (original) (raw)
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The Kabirkuh section in the Ilam Province of southwestern Iran contains one of the most complete Late Maastrichtian to early Danian sequences similar to those known from the eastern Tethys realm. The Cretaceous-Tertiary boundary is marked by a 1-2 cm thick kidney-red shale in the uppermost Gurpi Formation. All Late Maastrichtian planktonic foraminiferal biozones CF1 to CF4 (equivalent to the Abathomphalus mayaroensis zone) and Danian zones P0 (Parvularugoglobigerina extensa), P1a (Parvularugoglobigerina eugubina) and Parasubbotina pseudobulloides are present. Faunal studies show that all but six of the Cretaceous species identified (22 of 29 species) disappeared at or below the K-T boundary in zone CF1 (P. hantkeninoides). Another 6 species (Heterohelix globulosa, H. navarroensis, H. dentata, Hedbergella monmouthensis, H. holmdelensis, Guembelitria cretacea) appear to have survived into the early Danian. Early disappearances appear to be environmentally controlled. Coarse ornamented species with small populations disappeared first, whereas small species with little or no ornamentation and generally large populations tended to survive after the environment changing. This indicates a pattern of gradual and selective faunal turnover in planktonic foraminifera during the latest Maastrichtian and into the earliest Danian that is similar to that observed at the El Kef stratotype of Tunisia, as well as K-T sequences in Egypt, Italy, Spain and Mexico.
International journal of geography and geology, 2014
The objective of the present study is to perform Microbiostratigraphy and Lithostratigraphy of the Upper Permian Dalan Formation at a Well (Well 1) in the Zagros Basin. The Upper Permian Dalan Formation contains vast gas reservoirs in the southwest Iran and is composed of three Members: The Lower Dalan Member corresponds to Wordian to Capitanian; the Nar Member is latest Capitanian and the Upper Dalan Member corresponds to Wuchiapingian to Changhsingian. Lower and Upper Dalan Members include mainly limestone, dolomitic limestone and Nar member mostly consists of anhydrite and thin interlayer of dolomite. The biostratigraphic study allows individualizing Foraminifers from the Wordian to the Changhsingian (Middle to Late Permian). Based on the stratigraphic distributions of the Biostratigraphically significant fauna and flora the following 7 biozones and age determinations are proposed in the Upper Permian Dalan Formation: 7. Paraglobivalvulinoides septulifera zone (Changhsingian) 6. Paradagmarita zone (Changhsingian) 5. Rectostipulina zone (Wuchiapingian) 4. Shanita zone (Capitanian) 3. Paraglobivalvulina zone (Capitanian) 2. Globivalvulina zone (Wordian) 1. Eoverbeekina zone (Wordian)
2017
The Mississippian-Asselian (Early Carboniferous-Early Permian) foraminiferal faunas and biostratigraphy were studied in three sections of the Shahreza-Abadeh regions, in the Sanandaj-Sirjan Zone, in Iran. These sections with a thickness of about 528-1180 m are mainly composed of the siliciclastics and fossiliferous carbonates carbonates, apparently deposited in a shallow-water environment. The studied successions consist of Carboniferous Shishtu and Sardar groups and the uppermost Carboniferous-Lower Permian Anarak Group. The sequence in question contains 217 species belonging to 75 genera within the six foraminiferal zones; namely, (1) the Uralodiscus rotundus-Glomodiscus miloni zone of a Viséan age, (2) the Plectostaffella jakhensis-Eostaffella pseudostruvei zone of a Voznesenian (earliest Bashkirian) age, (3) the Tikhonovichiella tikhonovichi-Profusulinella (Depratina) prisca-Aljutovella spp. zone of a Melekessian-Vereian (latest Bashkirian-earliest Moscovian) age, (4) the Beedeina samarica-Taitzehoella mutabilis zone of a late Kashirian age, (5) the Fusulinella (Fusulinella) pseudobocki zone of an early Podolskian age, and (6) the Praepseudofusulina kljasmica zone of a latest Gzhelian-Asselian age. Among the identified foraminifers, 21 genera and 37 species are reported for the first time in the Sanandaj-Sirjan Zone. The foraminiferal zones and their characteristic index species allow to correlate the Mississippian-Asselian sequence in the Sanandaj-Sirjan Zone with the foraminiferal biozonation acknowledged for the Mississippian-Asselian in the the Russian Platform, Southern and Northern Urals, Istanbul Terrane, Eastern and Central Taurides (Turkey), and Western Europe. These new foraminiferal faunas, U n i v e r s i t y o f M a l a y a iv furthermore, share some common species with the concurrent faunas of the Alborz, East Iran, and Central Iran. In this study, the foraminiferal assemblages of the Voznesenian (earliest Bashkirian) age, the Melekessian-Vereian (latest Bashkirian-earliest Moscovian) age, and also the Biozone MFZ11B (late early Viséan) are reported for the first time in the Sanandaj-Sirjan Zone. The study also presents the occurrence of 19 species of foraminifers for the first time in Iran.
2013
TheMiddle–Upper Permian (Guadalupian–Lopingian) Dalan Basin was part of a verylarge carbonate ramp/platform along the passive margin of the Arabian Plate,located at mid-latitude Neo-Tethys Ocean. As shown in the modern world themid-latitudes are areas where climatic fluctuations and velocity of climatechange are most significant. Consequently, the most significant variations inforaminiferal diversity occur at higher latitudes as already noted for theMiddle Permian (Guadalupian) foraminifers’ record. The fusulinids as a large,warm-water foraminifera were quite sensitive to water temperature. The optimalwater temperature for recent warm-water benthic foraminifera with livingsymbionts, and consequently for fusulinids, is 20–30°C, while the lower limit is 14–16°C. Three climatically-determinedassemblages were distinguished in Zagros and the surrounding areas. The firstassemblage is characteristic of temperate, cool-water environments and containssmaller foraminifera with no symbionts, w...
Revista Brasileira De Paleontologia, 2022
The Paleogene carbonate deposits of Pabdeh and Jahrum formations are widespread in the northwest of the Shahrekord region (Dashte Zari area) in the High Zagros Mountains of Iran and record lateral and upward transition from open marine into shallow water environment within the Zagros foreland basin. The Pabdeh Formation shows a succession of open marine pelagic and hemipelagic limestone, argillaceous limestone, and argillaceous chert. It consists of planktonic wackestone, pellet-planktonic wackestone, mudstone with planktonic foraminifera, and radiolarian siliceous wackestone. The planktonic foraminifera are assigned to the Late Paleocene to Late Eocene, and correspond to subtropical to tropical Zones P4b-E15. Only one planktonic biozone (Zone E12), which corresponds to the high level stand of the Bartonian climate optimum (MECO) was not recognized in likely response to a tectonic event.The Jahrum Formation is represented by bioclast-bearing limestone and calcarenite. It consists of benthic foraminiferal wackestone, benthic foraminiferal-red algal packstone, and bioclast-intraclast packstone deposited in a shallow platform environment. The Jahrum Formation is inter-fingered in the upper part of the Pabdeh Formation and finally overlies it conformably during the Bartonian-Priabonian. Shallowing and offlap relationships record basin shrinking, while repeated interfingering signals moderate tectonic subsidence. Both formations are disconformably covered by the Late Oligocene-Miocene Asmari Formation.
Geoscience Frontiers, 2015
The Asmari Formation is a predominantly carbonate lithostratigraphic unit that outcrops in the Zagros Basin. Micropaleontological studies of the Asmari Formation in the Dehdasht area led to the identification of 51 species of foraminifera taxa. Among the foraminifera, Nummulites cf. vascus, Operculin sp., Operculina complanata, Eulepidina dilatata, Eulepidina elephantine, Ditrupa sp., Miogypsina sp., Elphidium sp. 14, and Borelis melo curdica are the most important. The Lepidocyclina-Operculina-Ditrupa assemblage zone represents the RupelianeChattian age. The Aquitanian age is also defined by co-occurrence of Miogypsina sp. and Elphidium sp. 14, and finally, the first occurrence of Borelis melo curdica represents the Burdigalian. Based on faunal assemblages, the following paleoenvironmental settings are determined for the deposition of the study section: (1) the deep, offshore settings in the aphotic zone dominated by pelagic and small benthic foraminifera; (2) the low energy, turbid and low light parts of the oligophotic zone characterized by large and flat lepidocyclinids (Eulepidina) and Nummulitidae; (3) the low turbidity, deeper part of the inner ramp dominated by Miogypsinoides, Neorotalia, Lepidocyclina, Operculina and Archias; (4) the shallow, marginal marine environment exposed to salinity fluctuations (short-term salinity fluctuations or fully marine conditions) dominated by small benthic Foraminifera (Ammonia and Elphidium); (5) highly translucent, shallowest part of the inner ramp dominated by representatives of Borelis, Meandropsina and Peneroplis. The biotic assemblages represent warm tropical waters with oligotrophic to slightly mesotrophic conditions.
VII International scientific and practical conference ( March 31, 2023), Conference bulletin, 2023
This study is focused on the foram-iniferal biostratigraphy and paleoecology of the Guri Member (Mishan Formation) northwest of Bandar Abbas, south of Iran, and in the Zagros Basin (eastern Tethyan province). The Guri Member mainly consists of medium- to thick-bedded limestone, medium-bedded marly lime-stone, and green marl with intercalated medium, brown limestones. In this study, five benthic foraminiferal biozones were established, includ-ing 21 benthic foraminiferal species from 17 genera. A comparison of the identified benthic foraminiferal biozones of the Guri Member with those in other parts of the world reveals close similarity to the Tethyan realm. Foraminifera confirms the Early to middle Miocene for the Guri Member. Seven marine high calcareous rare Ostracoda species were found in marl sediments only, not in Limestone layers. The biotic associations identified in this study sug-gest that the carbonate sedimentation of the Mishan Formation from the lower part to the upper part thrived in subtropical to tropical envi-ronments, reflected mesotrophic to oligotrophic conditions, deposited soft to hard sediments at water depths that ranged from 20–80 m, and deposited in a normal water salinity environment that ranges from 34 to 50 ‰.
Jsc «Publishing House – South»--Academician of the International and Russian engineering academies, Anatoly Ivanovich Bulatov, 2023
This study is focused on the foram-iniferal biostratigraphy and paleoecology of the Guri Member (Mishan Formation) northwest of Bandar Abbas, south of Iran, and in the Zagros Basin (eastern Tethyan province). The Guri Member mainly consists of medium- to thick-bedded limestone, medium-bedded marly lime-stone, and green marl with intercalated medium, brown limestones. In this study, five benthic foraminiferal biozones were established, includ-ing 21 benthic foraminiferal species from 17 genera. A comparison of the identified benthic foraminiferal biozones of the Guri Member with those in other parts of the world reveals close similarity to the Tethyan realm. Foraminifera confirms the Early to middle Miocene for the Guri Member. Seven marine high calcareous rare Ostracoda species were found in marl sediments only, not in Limestone layers. The biotic associations identified in this study sug-gest that the carbonate sedimentation of the Mishan Formation from the lower part to the upper part thrived in subtropical to tropical envi-ronments, reflected mesotrophic to oligotrophic conditions, deposited soft to hard sediments at water depths that ranged from 20–80 m, and deposited in a normal water salinity environment that ranges from 34 to 50 ‰.
International Journal of Geography and Geology, 2015
Fahliyan and Gadvan Formations belong to Lower Cretaceous formations of Zagros basin. Fahliyan is the third formation of Khami Group which is amongst the most important oil and gas reservoirs in southwestern Iran. This formation in accompany with Gadvan and Dariyan Formations form Upper Khami. In this research, Fahliyan and Gadvan Formations with Lower Cretaceous (Neocomian-Aptian) age in Kuhe-e-Surmeh section were studied in order to evaluate lithostratigraphy and microbiostratigraphy. Microbiostratigraphical studies led to identify 54 genera and 86 species of foraminifers and algas. According to these microfossils, two biozones of Pseudocyclammina lituus-Dukhania Arabica-Algal zone ll with Neocomian age and Orbitolina-Choffattella-Salpingoporella dinarica zone I with Barremian-Aptian age were suggested.