Red River Fault Zone affected the formation of basins in the western South China Sea: An experimental study

The strike-slip movement of the Red River Fault Zone (RRFZ) affected the formation of the basin in the western part of the South China Sea (SCS) to a certain degree. To characterize the tectonic features of the RRFZ during the uplift interval of the Tibetan Plateau and analyze the relationship between the strike-slip in RRFZ and the basins, especially Yinggehai Basin and Zhongjiannan Basin in the western SCS, sandbox analogue modelling experiments were performed in the context of the India-Eurasia collision. Results indicate that the prototypes of the two basins are controlled by the NW-oriented shear stresses generated by the strike-slip movement of the RRFZ, and the SN-oriented tensional stresses with the SCS opening up and the basin sizes expanding. During the early formation stage of the two basins, the displacement due to the strike-slipping was absorbed by the boundary faults and internal faults of the basins, thus controlling the evolution of the basins during the stage from 35 to 23 Ma.