Document Type : Original Research Paper

Authors

1 Associate Professor, Department of Mining, Imam Khomeini International University, Qazvin, Iran

2 Assistant Professor, Department of Remote Sensing, Dezful Branch, Islamic Azad University, Dezful, Iran.

10.22071/gsj.2022.302632.1935

Abstract

Pabdeh Formation to Asmari Formation transition deposits were studied in the stratigraphic section of Khaviz located northeast of Behbehan. In the present research, the deposits of the upper part of Pabdeh Formation consisting shale and interbedded of argillaceous gray limestone with a thickness of about 66 m were studied, which followed by deposits of the lower part of Asmari Formation with a thickness of about 21 m, including cream-colored clay limestone located. As a result of this study, 33 species belonging to 15 genera of calcareous nannofossils were identified. Based on the recorded bio-events and associated fossil assemblages, the bio-zones of Sphenolithus pseudoradians Zone, Ericsonia subdisticha Zone, Helicosphaera reticulata Zone, Sphenolithus predistentus Zone, Sphenolithus distentus Zone were determined. The studied zones are consistent with CNE20- CNO4‌/ CNO5 from Agnini et al. (2014) zonation. Based on the introduced bio-zones, the age of the upper part of Pabdeh Formation in the studied section of the Priabonin-early Rupelian and the age of the lower part of the Asmari Formation Rupelian -Chattian are suggested. In this study, the boundary between Pabdeh and Asmari formations is continuous, which indicates sedimentation with decreasing depth in the boundary of these two formations.

Keywords

Main Subjects