Biostratigraphy of the Cretaceous deposits based on Calcareous nannofossils in the Kuhbanan section (northwest Kerman, Central Iran sedimentary basin)
Subject Areas :
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Keywords: Central Iran Biostratigraphy, Calcareous nannofossils, Cretaceous, Kerman. ,
Abstract :
To study the microbiostratigraphy of Cretaceous deposits in central Iran, the Kuhbanan section in northwest Kerman was selected. Investigated thickness of the Cretaceous deposits in this section is 326 meters and mostly consists of marl and limestone. The studies led to the identification of 17 genera and 38 species of calcareous nannofossils. Based on the index calcareous nannofossils, this section was divided into four standard biozones: Chiastozygus litterarius zone, Prediscosphaera columnata zone, Eiffellithus turriseiffelii zone, and the lower boundary of Microrhabdulus decoratus zone. Based on these biozones, the deposits studied in this section span the Aptian to early Cenomanian. The first occurence of Microrhabdulus decoratus along with Braarudosphaera bigelowii in the Cenomanian and the last occurence of Eiffellithus parvus, Lithraphidites alatus, and Braarudosphaera africana in the Cenomanian indicate the transition from the early Cretaceous to the beginning of the late Cretaceous in this section.