The Wan-An fault and its relationship with the Wan-An Basin, western South China Sea

摘要

The Wan An Basin, a major basin located in the southwestern part of the South China Sea, is suggested to be closely related to the extrusion of the Indo-China Block. But the published documentation about the Wan An Basin is very sparse. High-resolution seismic reflection profiles obtained by the petroleum industry along the southwestern margin of the South China Sea provide us a chance to study the characteristics of the Wan-An fault and its relationship to the Wan-An Basin. The Wan-An Fault staggered strata in the Wan-An Basin and formed negative flower structures. The deformation related to the Wan-An fault is localized along the fault, while the strata away from the strike-slip fault were not affected. The characteristics of strike-slip extensional basin are not obvious in the Wan-An Basin. However, this basin has obvious characteristics of rift basin. Initial analysis shows that the Wan-An Basin should be a continental margin rift basin.