Microfacies analysis and depositional environment of Qom Formation in the Bijegan area (northeast of Delijan)

The Qom Formation deposits in the Bijegan area، northeast of Delijan، are Rupelian-Chattian in age، with a thickness of 162 meters. It consists of sandy limestone، thin to medium and thick bedded and massive limestone. It is disconformably overlain the Lower Red Formation. The upper boundary is covered by alluvium. 8 carbonate microfacies related to semi- restricted lagoon and open marine (slope) environments identified. Based on 120 thin section studied، microfacies analysis and field observation the Qom Formation in the study area deposited on an open shelf setting.