Evidence of late quaternary activity of the Weining-Shuicheng Fault in Guizhou, China

The Weining-Shuicheng Fault (WSF) is a northwest-southeast trending fault in the southwest of the South China Block (SCB), which is an important component of the Yadu-Ziyun Fault Zone. The study of its activity is of great significance for analyzing the boundary role of the Daliangshan secondary block on the SCB. This paper derived the following results through field investigations, high-precision remote sensing image interpretation, UAV photogrammetry, trenching technique, and AMS C-14 age. The WSF is northwest-trending with a sinistral strike-slip. It has a total displacement of about 2.5-3.2 km, which is equivalent to that of the southern section of the Daliangshan Fault. There are visible landforms such as fault scarps and fault valleys along the WSF, which control the development of the Caohai Basin. The gully near Weining Airport was caused by left lateral dislocations with a displacement of about 4 m. The Tashan trench revealed two branching faults, cutting the latest strata formed during about 13,000 BC. The Wangjiachong trench revealed five branching faults, cutting the latest strata formed during about 20,000 BC. The northern section of the WSF is flower-shaped tectonic features near the plane and activated in the Late Pleistocene.