Biostratigraphic correlation of Santonian-Maastrichtian calcareous nanofossil biozones with planktonic foraminifera zonation, Interior Fars region of the Zagros, southwest Iran

Received data considered the stratigraphic distribution of nanofossils and compared with planktonic foraminifera in the Sepidan section. The Gurpi Formation is well exposed in the Sepidan section, Interior Fars, southwest Iran. It consists of 358 m of shale and argillaceous limestone with lime shale. Thirty-nine calcareous nannofossils species from 19 genera were identified in the Sepidan section. According to the distribution of calcareous nannofossil assemblages, the Upper Cretaceous succession was subdivided into 12 biostratigraphic zones, suggesting the late early Santonian to latest Maastrichtian age. Also, the examination of the studied samples resulted in the identification of 20 planktonic foraminifer taxa, assigned to seven genera. Based on the stratigraphic distribution of the planktonic foraminifera, nine foraminiferal biozones were determined. Foraminiferal investigations show that the age of the Gurpi Formation is assigned to the Santonian to late Maastrichtian. Both established nanofossil and planktonic foraminifera biozones were correlated.