Deep Duplex Thrust in the Sangzhi-Shimen Tectonic Belt, in the West Hunan and Hubei Areas

Recent studies indicate that there is a large buried body developing in the Sangzhi-Shimen tectonic belt, which is between the Xuefeng intracontinental deformation system and the Xiangexi tectonic belt. In order to explore the tectonic evolution and main deformation-controlling factors of the buried body, we carried out a series of studies and built two new models based on the latest seismic data and fault-related fold theory. These new models show that the deformation of the buried body in the north segment of the study area is different from that in the middle-south segment. After further study, we found the main factors leading to these differences were: (1) the magnitude of the principal stress, (2) the range of tectonic movements, and (3) the morphology and the depth of the basement detachment. Subsequently, with the physical simulation experiments, a 3D evolution model of the study area was built.