Calcareous nannofossil biostratigraphy of the Cretaceous deposits in Khunik startigraphic section (West Qaen, eastern Iran)

In this research, the biostratigraphy of the Cretaceous deposits was investigated in the eastern margin of Lut Block in Khunik startigraphic section, west of Qaen, based on calcareous nannofossils. The stratigraphic interval mainly consists of marls with sandstone interlayers (196 m thick). According to the systematic studies, 30 nannofossil species belonging to 20 genera were identified. Based on the presence of index calcareous nannofossils such as Calcicalathina oblongata, Speetonia colligata, Eiffellithus striatus and the fossil assemblages Calcicalathina oblongata Zone (CC3), Cretarhabdus loriei Zone (CC4) and Lithraphidites bollii Zone (CC5) these deposits are equivalent to NK3A subzone – middle part of NC5B subzone. According to the determined biozones, early Valanginian to late Hauterivian age was suggested for the studied interval.