The Sangzhi-Shimen synclinorium, which is in the western margin region of the Hunan-Hubei Province and as the southeast part of the middle Yangtze platform, is a second-level tectonics unit in the south of this region...The Sangzhi-Shimen synclinorium, which is in the western margin region of the Hunan-Hubei Province and as the southeast part of the middle Yangtze platform, is a second-level tectonics unit in the south of this region. Along the profile, it can be divided into 5 third-level structure belts. By the comprehensive interpretation of seismic data and magnetotelluric (MT) sounding data, it is found that the surface structure is not in accordance with that of the underground, and this un-coordination can be conducted by many decollement surfaces between the layers. There are three periods of deformation in its geo-history in this region: before the early (Yanshan) stage, during the early Yanshan stage and after the early Yanshan stage, while the main deformation period is during the early (Yanshan) stage. And the mechanism of deformation is the thrust faults in basement, which are controlled by many decollements, in addition to the decollement of the cap-rock.展开更多
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 expl...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 depth of the basement detachment.Subsequently,with the physical simulation experiments,a 3D evolution model of the study area was built.展开更多
文摘The Sangzhi-Shimen synclinorium, which is in the western margin region of the Hunan-Hubei Province and as the southeast part of the middle Yangtze platform, is a second-level tectonics unit in the south of this region. Along the profile, it can be divided into 5 third-level structure belts. By the comprehensive interpretation of seismic data and magnetotelluric (MT) sounding data, it is found that the surface structure is not in accordance with that of the underground, and this un-coordination can be conducted by many decollement surfaces between the layers. There are three periods of deformation in its geo-history in this region: before the early (Yanshan) stage, during the early Yanshan stage and after the early Yanshan stage, while the main deformation period is during the early (Yanshan) stage. And the mechanism of deformation is the thrust faults in basement, which are controlled by many decollements, in addition to the decollement of the cap-rock.
基金supported by the National Science and Technology Major Projects(No.2011ZX05008-001)the National Natural Science Foundation of China(Nos.40739906,41272237)
文摘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 depth of the basement detachment.Subsequently,with the physical simulation experiments,a 3D evolution model of the study area was built.
