Microfacies, depositional model and sequence stratigraphy of Dariyan Formation in Northern high Zagros fault

Dariyan Formation deposited in two different sedimentary settings. In some places it consists of shallow Limestone with algae and Orbitolina and in the other places in addition to limestone, it represents black shales and marls associated with planktonic foraminifera and radiolarian. In this research Draiyan Formation was studied in order to microfacies, depositional model and sequences stratigraphy of two sections so called, Kuh-e Gadvan and Kuh-e Banesh in high Zagros belt. Detailed petrographic studies led to the recognition of five main facies belts including: lagoon, bar, shallow open marine, outer ramp and deep marine. According to the vertical and lateral variations of facies, the Dariyan Formation deposited on a carbonate ramp platform and intrashelf basin. Depositional sequences have been presented on the basis of analysis of facies, fauna assemblages, Gama and Neutron logs. Three 3rd orders depositional sequences have been recognized during deposition of sediments. There is Type I sequence boundary in the top of third sequence and the other two sequences was considered as Type II sequence. Sea level fluctuations of the studied area correlated with Arabian platform and these changes follow of regional factors.