Calcareous nannofossil biostratigraphy in the upper part of the Garau Formation in the Sheikh Saleh section in Northwest of Kermanshah, Lurestan Province (Zagros Basin)

In this study, the upper part of the Garau Formation with a thickness of 24 m in the section of Sheikh Saleh anticline located in the northwest of Kermanshah was investigated from the calcareous nannofossils. In this section, the Garau Formation is mainly composed of medium bedded argillaceous limestone. In order to introduce the index species and biozones, 17 slides from the Garau Formation were studied, which resulted in the identification of three biozones. As a result of this study, 20 species and 15 genera of calcareous nannofossils were identified. Based on the obtained biozones, the age of the upper part of the Garau Formation in the studied section is suggested the late early Cenomanian to the late late Cenomanian. This age is corresponding to the upper part of Eiffellithus turriseiffelii Zone (CC9), Microrhabdulus decorates Zone (CC10), lower part of Quadrum gartneri Zone (CC11) from the Sissingh (1977) zonation and UC1, UC2, UC3, and lower part of UC7 from the Burnett (1998) zonation.