Sedimentology and depositional system of a structurally constrained Tertiary basin: Lower and Middle members of the Eocene Musawa Formation in Northeastern Oman

The Middle Eocene sedimentary succession in Abat Basin in the southeastern Oman Mountains contains an exceptionally thick fluvio-deltaic siliciclastic sequence belonging to the lower and middle part of the Musawa Formation. The Abat Basin is tectonically constrained by three bounding faults that controlled subsidence and deposition in the mini-basin. The 350 m thick westward dipping deltaic sediments of the lower member of the Musawa Formation show two main facies successions over ten km distance, grading from a proximal delta plain to a distal delta front succession. About 500 m thick middle member of the formation shows deposition on a carbonate platform without any significant siliciclastic input. In this study we will analyze these rocks in field to identify major lithofacies associations to determine the depositional system of the lower and middle members of the Musawa Formation. This study will help to understand the depositional setting of a mini-basin named as the Abat Basin created during Middle Eocene extensional events in southheastern Oman mountains. The Abat Basin was created during Eocene time due to movement along bounding faults of north Ja?alan and Qalhat faults. The Abat Basin was filled with thick siliciclastic sediments when most of Oman was experiencing carbonate sedimentation during a sea-level high prevailing in the Arabian Peninsula.