In this study, Abderaz Formation at six stratigraphical sections, in east and center of the Kopeh-Dagh sedimentary basin, has been investigated, based on biserial planktonic foraminifera. Totally, 831 samples, with 3 ...In this study, Abderaz Formation at six stratigraphical sections, in east and center of the Kopeh-Dagh sedimentary basin, has been investigated, based on biserial planktonic foraminifera. Totally, 831 samples, with 3 meter distance, were gathered from a sequence with 2800 meter thickness. Also 4 genera and 17 species of biserial planktonic foraminifera have been identified and two biozones and two subzones recognized. Based on obtained data, the age of Early Turonian-Earliest Campanian for the Padeha, Abderaz village and Shorab sections, Midle Turonian-Earliest Campanian for type section, Early Turonian-Late Santonian for Qarehso section and Early Turonian-Earliest Santonian for Hajgelichkhan section were determined. The least amount of plank-tonic foraminifera was identified at Hajgelichkhan, while the maximum amount recognized at Qarehso section.展开更多
In this research, the Turonian-early Campanian sedimentary succession of the Abderaz Formation with 510 mthick (comprising: light grey shale and marls) was studied in the type section in eastern Kopeh-Dagh basin. The ...In this research, the Turonian-early Campanian sedimentary succession of the Abderaz Formation with 510 mthick (comprising: light grey shale and marls) was studied in the type section in eastern Kopeh-Dagh basin. The statistical analysis of the morphotype groups of the identified planktonic foraminifers shows that most of them are shallow water forms (SWF) and deep water forms (DWF). The high planktonic to benthic ratio indicates particular oligotrophic conditions and sedimentation in relatively deeper zones of a marine environment. The salinity of sea water during Coniacian was in the minimum level, whereas it reached maximum in Coniacian-Santonian boundary. Comparing Planktonic assemblages from the study formation with those from the Cretaceous biogeographical provinces reflects a close relationship between the identified species and the planktonic forms of the Tethyan provinces.展开更多
文摘In this study, Abderaz Formation at six stratigraphical sections, in east and center of the Kopeh-Dagh sedimentary basin, has been investigated, based on biserial planktonic foraminifera. Totally, 831 samples, with 3 meter distance, were gathered from a sequence with 2800 meter thickness. Also 4 genera and 17 species of biserial planktonic foraminifera have been identified and two biozones and two subzones recognized. Based on obtained data, the age of Early Turonian-Earliest Campanian for the Padeha, Abderaz village and Shorab sections, Midle Turonian-Earliest Campanian for type section, Early Turonian-Late Santonian for Qarehso section and Early Turonian-Earliest Santonian for Hajgelichkhan section were determined. The least amount of plank-tonic foraminifera was identified at Hajgelichkhan, while the maximum amount recognized at Qarehso section.
文摘In this research, the Turonian-early Campanian sedimentary succession of the Abderaz Formation with 510 mthick (comprising: light grey shale and marls) was studied in the type section in eastern Kopeh-Dagh basin. The statistical analysis of the morphotype groups of the identified planktonic foraminifers shows that most of them are shallow water forms (SWF) and deep water forms (DWF). The high planktonic to benthic ratio indicates particular oligotrophic conditions and sedimentation in relatively deeper zones of a marine environment. The salinity of sea water during Coniacian was in the minimum level, whereas it reached maximum in Coniacian-Santonian boundary. Comparing Planktonic assemblages from the study formation with those from the Cretaceous biogeographical provinces reflects a close relationship between the identified species and the planktonic forms of the Tethyan provinces.
