Sedimentary characteristics, dispersal patterns, and pathway formation in Liaoxi Sag, Liaodong Bay Depression, North China: Evolution of source-to-sink systems in strike-slip tectonics belt

Liaodong Bay Depression is a strike-slip basin with complex tectonic movement that lead the source-to-sink (S2S) systems evolution vary greatly in temporal and spatial characteristics. This study explored the sedimentary characteristics, dispersal patterns, and pathway formation in Liaodong Bay Depression, as well as their controlling factors. We selected more than 10 pathways with north-west and north-east directions in Liaoxi Sag in the western part of Liaodong Bay Depression, a typical strike-slip bet controlled graben, to investigate their S2S system distribution. By combining seismic data, we divided the strike-slip fault bends into three stress setting parts, namely, a central restraining bend, which is the fault translation part, and two releasing bends in the southern and northern of fault terminals. As the heavy mineral assemblage and clay content in the west side of Liaoxi Sag differs from that in the east side, we put forward an S2S index to show the sediment transport distance according to the data we have obtained. Using this index, we recovered the dispersal pattern and pathway development and speculated on the sedimentary provenance. In the restraining bend, we recognized that the pathways mainly show a symmetrical "V" or "W" shape with unclear erosion boundaries and were dominated by filling processes. Considering the heavy mineral assemblage data, we also found that the sediment provenance area decreased and the sediment provided direction transferred from the two-side provenance to one. Combining the fast sedimentary rate calculated with clay content data, the S2S systems in this area were steep-wide-deep systems and a wide and shallow system. In the releasing bend, the pathways show an asymmetrical "V" or "W" shape and a clear erosional boundary. As shown by the heavy mineral assemblage data, the sediments from these areas mainly have a west side provenance and were deposited in the proximal area. Thus, the S2S system in this area is a kind of steep-deep system. Then, the investigation by integrated of tectonic movement and S2S geomorphic statistical parameters revealed that the elevation height of the S2S is a key factor in control pattern development. The various evolution patterns within the two different stress settings provide insights into the formation process of the S2S developed in a strike-slip tectonic belt.