摘要
In this paper, the authors summarized the geometric and geomorphologic features of the evolution of the pull-apart basin based on previous research results, and chose a small pull-apart basin along the Fuyun fault to study its geometric and geomorphologic characteristics. Based on the survey using the differential global positioning system (DGPS) measurement instruments— SOUTH 9600 Polaris and data processing using SOUTH GPS and SOUTH CASS7.0 software, the authors constructed the contour pattern of the basin. Then, according to the model which explains the offsetting and sinking change of the pull-apart basin before and after the earthquake, the authors calculated the depth of its detachment, which turns out to be about 40 m below the surface.