Microfacies, depositional environments and sequence stratigraphy of the Asmari Formation in Kuh-e Siah anticline north of Dehdasht, Zagros

The Asmari Formation deposited in the Zagros basin during the Oligocene-Miocene. In this study, microfacies, depositional environment and sequence stratigraphy of the Asmari Formation in Kooh-Siah anticline (north of Dehdasht) 127 sampels was studied. The thickness of the Asmari Formation in this section is 214m and consists of thick, medium and thin bedded limestones interbeded with marly limestone, dolomitic limestone and marl. Based on petrography and analysis of microfacies features,11 different microfacies types have been recognized,which can be grouped into 4 depositional environments:tidal flat, lagoon, shoal and open marine. The Asmari Formation represents sedimentation on a carbonate ramp. A HST in Chattian, three third-order depositional sequence in Aquitanian, and one third-order sequence in Burdigalian are recognized,on the basis of deepening and shallowing patterns in the microfacies.