Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depr...Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depression. The uplift and depression of the bedrock at a depth of 7km underground are＇consistent with the surface structure. 12 planar listric normal faults have developed above a depth of 18km -20km and two deep faults have developed in the lower crust. Because of the deep incision and new activities, the surface Wanggangpu-Xinehengzi fault and Yongle-Qingshuitai fault, which correspond to the deep F3 fault and F6 fault, might be related to seismic activity in Shenyang.展开更多
The Xiannvshan fault zone, lying along the western margin of the Huangling anticline, is one of the most important fault zones in the Three Gorges reservoir area. The fault experienced strong activity during the Cenoz...The Xiannvshan fault zone, lying along the western margin of the Huangling anticline, is one of the most important fault zones in the Three Gorges reservoir area. The fault experienced strong activity during the Cenozoic Era. The question of whether the fault zone goes through the Yangtze River has been one of the key problems faced in previous studies as it has a significant influence upon the assessment of geological hazards and earthquake stability in the reservoir area. Based on tectonic and geomorphic observations along the fault zone between the Baixianchi village in Changyang county and Huangkou village in Zigui town, together with the comparisons between the geology in Guizhou and Quyuan town in the north bank of the Yangtze River and the Xiannvshan fault zone, it is suggested that the north end of this fault zone is located around Huangkou village and does not go through the Yangtze rivers northward. The evidence is as follows: ① On the basis of field data collection, it is found that the Xiannvshan Fault zone, which stretches 80km, underwent thrust movement in the Cenozoic period, resulting in ravines and fault scarps, topographically. Whereas, on the northern bank of the Yangtze River, faults are rarely found, and most of the faults are developed in the Jurassic strata,without topographical effects. Therefore, the Xiannvshan Fault zone has not stretched to the north bank of the Yangtze River. ② The fault gouge and tectonite zone were found developed on the Xiannvshan Fault zone at Baixianchi village, but only a tectonite zone was found at Zhouping village. There are also some branch faults close to the northern end of the fault zone. So, the activity of the fault zone weakened from south to north in Cenozoic. The fault zone extends northward and dies out at Huangkou. It doesn't stretch forward any longer as indicated by continuous strata, sparse joints, and small folds, etc.展开更多
基金sponsored by the Active Fault Detecting Subprogram (2007-2230) of the"Chinese Digital Earthquake Observation Network"of the Tenth"Five-year Plan",China
文摘Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depression. The uplift and depression of the bedrock at a depth of 7km underground are＇consistent with the surface structure. 12 planar listric normal faults have developed above a depth of 18km -20km and two deep faults have developed in the lower crust. Because of the deep incision and new activities, the surface Wanggangpu-Xinehengzi fault and Yongle-Qingshuitai fault, which correspond to the deep F3 fault and F6 fault, might be related to seismic activity in Shenyang.
基金funded by Geological Disaster Preventing Project of the Third Stage of Three Gorges Project of Ministry of Land and Resources,China (SXKY3-5)the Basic Research Project of the National Non-profit Research Institutes,Institute of Geology,CEA(IGCEA1001)
文摘The Xiannvshan fault zone, lying along the western margin of the Huangling anticline, is one of the most important fault zones in the Three Gorges reservoir area. The fault experienced strong activity during the Cenozoic Era. The question of whether the fault zone goes through the Yangtze River has been one of the key problems faced in previous studies as it has a significant influence upon the assessment of geological hazards and earthquake stability in the reservoir area. Based on tectonic and geomorphic observations along the fault zone between the Baixianchi village in Changyang county and Huangkou village in Zigui town, together with the comparisons between the geology in Guizhou and Quyuan town in the north bank of the Yangtze River and the Xiannvshan fault zone, it is suggested that the north end of this fault zone is located around Huangkou village and does not go through the Yangtze rivers northward. The evidence is as follows: ① On the basis of field data collection, it is found that the Xiannvshan Fault zone, which stretches 80km, underwent thrust movement in the Cenozoic period, resulting in ravines and fault scarps, topographically. Whereas, on the northern bank of the Yangtze River, faults are rarely found, and most of the faults are developed in the Jurassic strata,without topographical effects. Therefore, the Xiannvshan Fault zone has not stretched to the north bank of the Yangtze River. ② The fault gouge and tectonite zone were found developed on the Xiannvshan Fault zone at Baixianchi village, but only a tectonite zone was found at Zhouping village. There are also some branch faults close to the northern end of the fault zone. So, the activity of the fault zone weakened from south to north in Cenozoic. The fault zone extends northward and dies out at Huangkou. It doesn't stretch forward any longer as indicated by continuous strata, sparse joints, and small folds, etc.
