A Holocene Yalu River-derived fine-grained deposit in the southeast coastal area of the Liaodong Peninsula

摘要

High-resolution seismic profiles and surface samples were studied in detail in order to determine the structures,provenance,and dynamic mechanisms of a fine-grained deposit in the southeast coastal area of the Liaodong Peninsula,China.Results indicate that there is a prominent fine-grained deposit distributed alongshore up to 14 m thick,which thins out to less than 2 m in both seaward and landward directions,forming an Ω-shaped pattem of cross-section.The deposit is 180-300 km away from the Yalu River mouth and extends along the southeast coast of the Liaodong Peninsula between the northeast of Dalian Bay and southwest of the Changshan Islands,in water depths of 20-40 m.The deposit,which is mainly derived from the Yalu River,represents a Holocene Highstand System Tract sequence formed since the highest sea level around 7.0 ka.The Yalu River-derived sediments were redeposited in the area off the southeast coast of the Liaodong Peninsula after resuspension and transportation by the Liaonan Coastal Current.