Depositional systems and windfield-source-basin system dynamics of the west sag, liaohe depression, bohai bay basin

Abstract

Beach bar deposits are widely distributed in the Eocene West Sag of Liaohe Depression. The formation is co-controlled by windfield, source, and basin. The ideal environment for its deposition includes three elements: (1) a consistent windfield, (2) relatively shallow water depth, and (3) a gentle lake-bottom slope. Five types of beach bar deposits are developed in the depression; they are formed by (1) reforming of delta side edge by waves, (2) reforming of delta front by waves, (3) reforming of bedrock by waves, (4) submerging and reforming of delta by rising water level, and (5) storming events.