Mohsen Allameh
Abstract
The Farrokhi Formation is the youngest sedimentary unit in Upper Cretaceous of Khur and Biabanak area. Its lithology is mainly consists of limestone, marl, marly limestone with intercalations of fossiliferous limestone. For environmental interpretation of this formation, 23 specimens of marly beds are ...
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The Farrokhi Formation is the youngest sedimentary unit in Upper Cretaceous of Khur and Biabanak area. Its lithology is mainly consists of limestone, marl, marly limestone with intercalations of fossiliferous limestone. For environmental interpretation of this formation, 23 specimens of marly beds are sampled and washed.. The study led to identification of 23 genera and 29 specious of ostracods. More than 87% of determined Ostracods have straight shell, without any ornamentation and connected to each other. It is concluded that the high rate in sedimentation led to well preservation of this fauna. According to the determined Ostracods, four ecofacies "i.e. littoral, inner neritic, outer neritic and outer neritic with low to high salinity and warm" are identified for the marly beds under study.
R. Haftlang; M. Afghah; S. A. Aghanabati; M. Parvaneh Nezhad Shirazi
Abstract
Lithological and biological Sequences of Cretaceous in Bahar section, Located in South Esfahan (147 m. true thickness) include grayish olive green pencil- like shales containing Budantysras Ammonites (Albian) interbedded with limy shales. which are covered by glauconitic Sandy Limestone (Early Turonian) ...
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Lithological and biological Sequences of Cretaceous in Bahar section, Located in South Esfahan (147 m. true thickness) include grayish olive green pencil- like shales containing Budantysras Ammonites (Albian) interbedded with limy shales. which are covered by glauconitic Sandy Limestone (Early Turonian) (with erosional discontinuity). These sandy limestones are wackestone and rarely greenstone, according to Dunham classification. Based on Biozone divisions, this unit is related to Biozone No. 27 presented by Wynd (1965) and it is equivalent to Sarvak Formation in Zagros. Marly limestone and limestone containing Inoceramus bivalve interbedded with marl dating back to Late, Middle Touronian- Late Touronian- Coniacian to Early Santonian are younger equivalents of this section which can be equaled to Surgah Formation. According to Biozone divisions, this unit is equivalent to Biozone No. 28 presented by Wynd (1965) and also based on Dunham classification, the unit is packestone and partly boundstone. The lower Contact of the unit is Concordant and Continuous with glauconitic sandy limestone and its upper Contact is Continuous and Concordant with marl and interbeddings of Limestones dating back to Santonian- Campanian. By comparing Bahar Section with South eastern Lorestan section (Poshte jangal anticline), (Azadbakht, 2015), the following results were obtained: From Litho/bio stratigraphical view, thick to thin-bedded Limestones (Light to dark gray) interbedded with marl in Poshte jangal anticline are Correlated with Inoceramus limestone and marly Limestone interbedded with marl in Bahar Section. They are dated back to EarlyTuronian to Early Campanian.Due to Strong similarity of Lithostratigraphy and biostratigraphy between Bahar section located in Southern Esfahan (Central Iran) and section of Poshte jangal anticline located in Southeast of Lorestan, it can be deducted that a branch of Lorestan Sea has advanced in Turonian- Coniacian times and some parts of Southern Esfahan has been covered by the sea.
F Mesbahi; M Mohajjel; M Moazzen; L Namaki
Abstract
In the east of Tabriz city, south of Eskandar village, Upper Cretaceous rock units are exposed. The structures in these rock units include meso-scale folds inclined towards NNE, and a thrust system which has transported Upper Cretaceous units in three thrust sheets towards NW. This thrust system has ...
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In the east of Tabriz city, south of Eskandar village, Upper Cretaceous rock units are exposed. The structures in these rock units include meso-scale folds inclined towards NNE, and a thrust system which has transported Upper Cretaceous units in three thrust sheets towards NW. This thrust system has cut the NNE-verging folds in Upper Cretaceous units. These deformed rock units are unconformably overlain by the Miocene beds. The vergence of folds in the Miocene units is toward SSW. There are SW-verging thrust faults and right-lateral strike-slip faults parallel to the North Tabriz fault in the study area. We conclude that the N-verging structures in Upper Cretaceous rock units has been formed in the time interval between Upper Cretaceous and Miocene and were cut by the North Tabriz fault. The structural characteristics of the Upper Cretaceous rocks as the remnants of the Upper Cretaceous oceanic crust in the Neotethyan marginal basin indicate that the probable subduction direction of this basin was towards south.
M. R. Esmaeilbeig
Abstract
The study of planktonic foraminifera of the Gurpi Formation at Kuh-e Khane Kat (east of Shiraz) led me to find standard biozones from Early Santonian to Middle Campaninan. Four biozones were determined: biozones I (Dicarinella asymetrica zone) and II (Rosita fornicata zone) belong to Early and Late Santonian. ...
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The study of planktonic foraminifera of the Gurpi Formation at Kuh-e Khane Kat (east of Shiraz) led me to find standard biozones from Early Santonian to Middle Campaninan. Four biozones were determined: biozones I (Dicarinella asymetrica zone) and II (Rosita fornicata zone) belong to Early and Late Santonian. Biozones III (Globotruncanita stuartiformis zone) and IV (Globotruncana ventricosa zone) represent the Early and Middle Campaninan. Due to a decrease in water depth in Kuh-e Khane Kat, Globotruncanita calcarata zone and other Maastrichtian plagic biozones were not recognized. In this section, Gurpi Formation is 220.5 meters thick and contains shale and argillaceous limestone. Its underlying and overlying formations are Sarvak and Tarbur.
M. Azizi; S. Senemari
Abstract
Using calcareous nannofossils is a powerful way for biozonation in sub-stage level, especially in the Late Cretaceous and Cenozoic, because they are planktonic, cosmopolitan, abundant and have very short age. Considering lack of any precise paleontological studies about the Gurpi Formation in the NW ...
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Using calcareous nannofossils is a powerful way for biozonation in sub-stage level, especially in the Late Cretaceous and Cenozoic, because they are planktonic, cosmopolitan, abundant and have very short age. Considering lack of any precise paleontological studies about the Gurpi Formation in the NW of shiraz (Bavan), nannofossils chose to investigate. This Formation consists of shale, marl and limestone. In this study, 23 genera and 46 species of nannofossils were identified. According to the identified marker species, 14 biozones were diagnosed that classified as CC14-CC26 and NP1(Base of the Pabdeh Formation). According to these biozones, it has been suggested that this section is aged of the Gurpi Formation from Early Santonian to Danian. The existence of CC26-NP1 zonal marker species of the K/T boundary has been considered which indicates continuous sedimentation from the Late Cretaceous to Early Paleocene.
