Upper Cretaceous Planktonic Foraminiferal Biostratigraphy of East Dorfak Area (Guilan – North of Iran)
1*Islamic Azad University – Science and Reserch Branch,Geology. department, Tehran, Iran. 2Islamic Azad University – Science and Reserch Branch,Geology.department, Tehran, Iran. 3Shahid Beheshti University– Geology department,Tehran, Iran.4Tehran Payamenour University–Geology department, Tehran, Iran. Email: Modaresiraza@Yahoo.Com
Abstract: East Dorfak(studied area) are located in Nothern Iran(within Gorgan-Rasht region). The Upper Cretaceous sequence in this region comprises three lithostratigraphic unites (K2SLm, K21, K2mL ). Two stratigraphic sections have been investigated in this area and outcrope samples collected in the measured sections. Previous studies have been very sparse and general.Consider of prepared thin sections and analysis the Late Cretaceous planktonic foraminifera content have presented detailed data. Identification of fifty-two index species belonging to the genera Dicarinella, Whtienella, Gansserina, Globotruncana, Globotruncanita, Globotruncanella, Contusotruncana, Macroglobigerinelloides, Marginotruncana, Radotruncana, Rugoglobigerina, Racemiguembelina, Heterohelix, Abathamphalus and Kuglerina has led to the recognition of nine (eight in Gurag section) biostratigraphic zones in this study. The biozones ranged in age from Coniacian to Late Maastrichtian.The Campanian and Early Maastrichtain demonstrated the largest diversity faunal. Sedimentary characteristics and planktonic foraminiferal content illustrated that deposition is done in deep marine environment. Moreover the study showed a little difference in the two sections under study.
[Mohammad Modaresnia, Khosro Khosrotehrani, Iraj Momeni, Seyed Ahmad Babazadeh. Upper Cretaceous Planktonic Foraminiferal Biostratigraphy of East Dorfak Area (Guilan – North of Iran). Life Sci J 2012;9(1):242-253] (ISSN: 1097-8135). http://www.lifesciencesite.com. 34
Keywords: Planktonic foraminifera; Biozone; Coniacian; Campanian; Maastrichtian; Cretaceous; Biostratigraphy; Iran.