Biostratigraphy and paleaoecology of the lower boundary of Neyzar Formation based on calcareous nannofossils in Dobaradar, Kalat and Chahchaheh sections

In present study، diversity and relative abundance of calcareous nannofossils of the boundary between Abtalkh and Neyzar Formations in Dobaradar، Kalat and Chahchaheh sections were studied. Taxonomical studies of calcareous nannofossils in the studied areas led to identification of 24 species in Dobaradar، 27 species in Kalat and 32 species in Chahchaheh sections. Based on identified nannofossils and biozones، the age of the studied portions in each of sections is late Late Campanian- Early Maastrichtian. The present of Watznaueria barnesae and absence of Biscutum constans suggest low productivity and the significant increases of Micula decussata show high-stress environmental conditions in this basin.