Lithostratigraphy and Biostratigraphy Based on Calcareous Nannofossils at the Late Campanian to Thanetian Transition in the Izeh Zone,Southwestern Iran(Eastern Neo-Tethys)  

作　　者：Senemari Saeedeh 

机构地区：[1]Faculty of Engineering,Imam Khomeini International University,Qazvin,Iran

出　　处：《Journal of Earth Science》2022年第4期1017-1030,共14页地球科学学刊（英文版）

基　　金：Imam Khomeini International University for all its support。

摘　　要：This study investigates the Gurpi Formation in the northeast of Izeh,southwestern Iran.In this study,59 species and 34 genera were determined.Biostratigraphy allows the identification of zones CC21 to CC26,which is equivalent to the UC15c^(TP)-UC20d^(TP) that spans the Late Campanian to Late Maastrichtian.Subsequently,the presence of NP1 to NP6,equivalent to CNP1 to CNP8,indicates that the sequence extends to Selandian.Then the Pabdeh Formation,which dates back to Thanetian,covers the sequence.Several major changes were recorded here in order of importance.The first change is the Campanian-Maastrichtian transition,which was identified based on the last occurrence of the Aspidolithus parcus constrictus.Subsequently,the Early/Late Maastrichtian boundary was determined based on the last occurrence of Reinhardtites levis.In addition,another change in the Late Maastrichtian–Early Danian is associated with an abrupt decrease in the richness of nannofossils,although a significant increase in the abundance of Early Paleocene new species has been observed along with the abundance of Thoracosphaera spp.blooms.Eventually,the final change coincides with an increase in Iridium throughout NP1.These changes may indicate changes in environmental conditions in this part of Iran during the Late Cretaceous–Paleogene transition in the eastern Neo-Tethys domain.

关 键 词：BIOSTRATIGRAPHY calcareous nannofossils Cretaceous Paleocene Zagros Basin TETHYS 

分 类 号：P539[天文地球—古生物学与地层学]