Stratigraphy and Palaeontology
Arash shabanpour Haghighie; Lida Bakhshandeh; Tayebeh Mohtat; Masood Zamanipedram; Seyed hamid Vaziri
Abstract
In this research the Gurpi Formation in the Zagros Basin outcropping in the Dasht-e Arjan section, Shiraz province ,for the purpose of biozonational and Paleobathymetric studies were investigated. The thickness of these sediments is about 130 m and consists of Limestones and Shales.To determine the palaeobathymetry ...
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In this research the Gurpi Formation in the Zagros Basin outcropping in the Dasht-e Arjan section, Shiraz province ,for the purpose of biozonational and Paleobathymetric studies were investigated. The thickness of these sediments is about 130 m and consists of Limestones and Shales.To determine the palaeobathymetry of the Gurpi Formation, Planktonic and benthic foraminifera were investigated . A depth of about 270m to 510m was determined for these sediments based on the ratio of planktonic foraminifera to the total assemblages of foraminifera after omitting infaunal benthic foraminifera (%P*) by using the equation D = e (3.58718+(0.03534 × %P* )).In this study sixty-two species of planktonic foraminifera belonging to eighteen genera were recognised .According to the studied planktonic foraminifera the Upper Cretaceous deposits in this area were divided into nine biozones as following :biozone1- Dicarinella concavata Interval Zone. Biozone2- Dicarinella asymetrica Total Range Zone. Biozone3- Globotruncanita elevata Partial range zone .Biozone4- Globotruncana ventricosa Interval Zone. Biozone5- Radotruncana calcarata Interval zone. Biozone 6- Globotruncanella havanensis Partial Range Zone. Biozone7- Globotruncana aegyptiaca Interval Zone. Biozone 8- Gansserina gansseri Interval Zone. Biozone 9- Contusotruncana contusa Interval ZoneBased on the studied planktonic foraminifera the Early Santonian to Maastrichtian ages were determined for the sediments .
Stratigraphy and Palaeontology
A. Shaabanpour Haghighi; , L. Bakhshandeh; T. Mohtat; , M. Zamani Pedram; S. H. Vaziri
Abstract
In this study the Upper Cretaceous sediments in the Zagrous Basins Fars province,the Pyrgheib Section,for the purpose of Biostratighraphy and sea level change studies were investigated. These sediments with about 206 m thickness consist of Limestone, Shale, Marl and limy marl. The investigated ...
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In this study the Upper Cretaceous sediments in the Zagrous Basins Fars province,the Pyrgheib Section,for the purpose of Biostratighraphy and sea level change studies were investigated. These sediments with about 206 m thickness consist of Limestone, Shale, Marl and limy marl. The investigated foraminifera led to identification of 70 species of planktonic foraminifera that belong to 16genera. Based on planktonic foraminifera the Upper Cretaceous deposits were divided into 6 biozone which are cosmopolitan and respectively are:biozone1 - Dicarinella concavata Interval Zone,Biozone2- Dicarinella asymetrica Total Range Zone,Biozone3- Globotruncanita elevata Partial range zone Biozone4- Globotruncana ventricosa Interval Zone,Biozone5- Radotruncana calcarata Interval zone. Biozone6- Globotruncanella havanensis Partial range zone ,Biozone7- Globotruncana aegyptiaca Interval zone. Biozone8- Gansserina gansseri Interval zone, Biozone9- Contusotruncana contusa Interval Zone. The Upper Cretaceous sediments in the study area on the basis of Planktonic Foraminifera are of the Late middle Coniacian to theLate Maastrichtian ages. According to the Morphotype groups of planktonic foraminifera deeping the basin from the Coniacian to the Middle Santonian is seen .However, in the late Santonian shallowing the basin and again in the Early Campanian deeping the basin, in the Late Campanian and close to the Campanian-Maastrichtian boundary shallowing the basin and a sea regression is observed.
Stratigraphy and Palaeontology
Fateme Mahdikhani; Mahmoud Reza Majidifard; T. Mohtat; L. Bakhshande; M. Zamanipedram
Abstract
In order to study the biostratigraphy and lithostratigraphy of the K/Pg boundary two sections was considered. They are the Kuh-e Zaluband and Kuh-e Hunu sections in east of Khur (Esfehan Province). At the Kuh-e Zaluband section has a maximum thickness of 100 m, consisting of marl, limestone, sandy limestone, ...
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In order to study the biostratigraphy and lithostratigraphy of the K/Pg boundary two sections was considered. They are the Kuh-e Zaluband and Kuh-e Hunu sections in east of Khur (Esfehan Province). At the Kuh-e Zaluband section has a maximum thickness of 100 m, consisting of marl, limestone, sandy limestone, sandstone and conglomerate and in the Kuh-e Hunu consisting of marl, limestone and sandy limestone. The lower part of the sections belonging to Farrokhi formation and upper part to Chupanan formation. Based of biostratigraphy at the study sections, summing up 88 thin sections were collected, among which the foraminifera with 17 specimens clearly predominate and belonging to 31 genera. Based on the foraminifera the age of the upper part of Farrokhi formation in the investigated area ranges Late Maastrichtian and Late Paleocene for lower part of Chupanan formation. Based on the paleontology, lithology and facies, there is disconformity in Cretaceous-Paleogene boundary in Kuh-e Zaluband and paraconformity in Kuh-e Hunu.
H. Hoseini; N. Kohansal Ghadimvad; M. Zamani Pedram; M. R. Majidifard; A. R. Shahidi
Abstract
Accumulation of Shemshak group lithofacies have been started during Early-Cimmerian orogeny from middle of Late-Triassic and ended with Middle- Cimmerian discontinuity dating Millde-Jurrasic. So the mostly Siliciclastic and occasionally Marin lithostratigraphic unite has evidences of two major tectonic ...
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Accumulation of Shemshak group lithofacies have been started during Early-Cimmerian orogeny from middle of Late-Triassic and ended with Middle- Cimmerian discontinuity dating Millde-Jurrasic. So the mostly Siliciclastic and occasionally Marin lithostratigraphic unite has evidences of two major tectonic events as orogenic activity at lower and upper border of sequence. Therefor the lower contact of Shemshak group is composed of Middle-Triassic platform carbonates known as Elika formation which distinguished with Plaeokarsts including bauxit and laterit horizons and the upper contact with parallel unconformity with Delichay formation fossiliferous marls and carbonates of Bajocian stage (Middle Jurrasic). Results of deposition environment and facies studies have shown that the mentioned siliciclastic group (Shemshak) composed of three major facies, 22 subfacies and have been deposited in three different environments including Fluvial (Terrestrial), mid-tidal and shallow marine environments. The vertical changes of facies have declared that the sequence has formed due to erosion of Early-Cimmerian uplands and have experienced progess of shallow marine. The existing shallow marine sediments in the end of Shemshak group states that, in comparison with surrounding area , clastic sediments of end of Shemshak cycle, because of erosional cycles of Middle-Cimmerian orogeny, befor deposition of Delichay marine formation, have been eroded.