Biostratigraphy of marine deposits of the Boujan section based on calcareous nannofossils (Southwest Kerman, Central Iran)

In the present study, for biostratigraphic studies based on calcareous nanoplankton, marine deposits attributed to the Oligocene of Boujan section in the Sirjan region (Central Iran) have been sampled. The studied deposits consist of marl, limestone and shaly limestone with 392 meters in thickness. In this study, 27 well- preserved species belonging to 10 nannofossil genera were identified. According to the identified index species and nannofossil assemblages, nannofossil biozones Helicosphaera reticulata Zone (NP22/ CNO2/ CP16c), Sphenolithus predistentus Zone (NP23/ CNO3-CNO4/ CP17-CP18), Sphenolithus distentus Zone (NP24/ upper part of CNO4- lower part of CNO5/ CP19a), and Sphenolithus ciperoensis Zone (NP25/ upper part of CNO5-CNO6/ CP19b- CN1b) were determined for the studied deposits. Based on the stratigraphic position of investigated taxa and determined biozones, early Oligocene to late Oligocene (Rupelian to Chattian) was suggested for the investigated deposits. Based on the stratigraphic position of investigated taxa and determined biozones, early Oligocene to late Oligocene (Rupelian to Chattian) was suggested for the investigated deposits.