Controls of strike-slip faults on geomorphology and sediment dispersal in the Paleogene Bohai Bay area—from a source to sink perspective

This study utilized drilling and 3D seismic data to investigate the control of strike-slip faults on the dynamics of different morphological elements and associated sediment dispersal from a source to sink perspective. Three types of geomorphological elements and associated depositional systems were identified. Two types of sediment dispersal systems consisting of different source areas, sediment transport conduits, and sediment infillings were also identified. The spatial and temporal variations in the geometry and kinematics of strike-slip faults control the dynamics of sediment dispersal systems. Inner-basin systems are mainly controlled by the ancient stress field variations generated by changes in the fault strike of the main strike-slip faults. Outer-basin systems are mainly controlled by the temporal kinematic variations of strike-slip faults. Sediments were supplied transversely into the basin during the early extension dominant stage (the deposition period of Ek-Es3), whereas the movement was axial or longitudinal during the strike-slip dominant stage (Ed). This study also suggests that the axial transport of sediment through the axial fault trough is the main sediment dispersal pattern along the side of the gentle slope within strike-slip fault-controlled basins. Additionally, results of this study could help model the locations of sand-rich areas in a strike-slip fault-controlled basin. •Two types of sediment dispersal systems with variable morphology and infilling are distinguished.•Strike-slip fault controls the development of sediment dispersal systems.•A double layers model with different sediment dispersal patterns is established.