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  2. 地质与地球物理研究所
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  4. 岩石圈演化国家重点实验室
The mechanism of deep material transport and seismogenic environment of the Xiaojiang fault system revealed by 3-D magnetotelluric study

文献类型：期刊论文

作者Yu, Nian1,2; Wang, Xuben3; Li, Dewei3; Li, Xin4; Wang, Enci1; Kong, Wenxin2; Li, Tianyang2
刊名SCIENCE CHINA-EARTH SCIENCES
出版日期2022-04-18
页码18
ISSN号1674-7313
关键词The Xiaojiang fault Magnetotelluric Seismogenic environment Emeishan mantle plume Crustal flow
DOI10.1007/s11430-021-9914-3
英文摘要The Xiaojiang fault system (XJFS), located to the southeast of the Tibetan Plateau, has a complicated tectonic history and is an ideal location to study the Tibetan Plateau in terms of its deep material transport mechanism and the effects of past tectonic events. In this study, broadband and long-period magnetotelluric data were collected above this fault system and inverted to build a 3-D resistivity model of the lithosphere. As shown in the model, at upper-middle crustal depths, three high-resistivity anomalies separate the strike-slip faults located in the study area, which may be the remnants of the Emeishan large igneous province that was destroyed and modified by Cenozoic crustal activity. The lower crust is characterized by significant low-resistivity anomalies that extend downward to the upper mantle. The low-resistivity anomalies in the upper crust may be caused by brines or/and conductive minerals (e.g., graphite and sulfides), and the possible reason for the low-resistivity anomalies that were imaged in the lower crust and upper mantle may be the presence of hydrogen in nominally anhydrous minerals and partial melts. According to the seismic activity distribution and resistivity structure, we propose dividing the seismic activity of the study area into three categories: tectonic earthquakes, earthquakes with no active faults on the surface, and other scattered earthquakes with no general features. Seismic activities are controlled by tectonic activities, fluid transportation, and the adjustment of the Earth's stress field. It is believed that there is a mutually reinforcing relationship between seismic activity and deep fluids. Fluids could lower the frictional force in faults, promote movement, and thus induce earthquakes; on the other hand, seismic activities and the long-term strike-slip movements of faults could generate heat and increase the connectivity of fluids, which decreases the strength of the crust and facilitates the flow of fluids. Based on the resistivity model, it is demonstrated that the present tectonic activity in the XJFS is complicated and characterized by rigid block extrusion along strike-slip faults in the upper crust, ductile deformation with channel flow in the lower crust, and the upwelling of mantle materials. In combination with previous studies, our results indicate that the weak crustal materials from the Tibetan Plateau are blocked by (1) the lithosphere modified by the Emeishan plume and (2) the South China block when flowing through the Sichuan-Yunnan block. Therefore, these weak materials turn to the southwest direction along the XJFS, then pass through the Red River fault and enter the Indochina block.
WOS关键词RAYLEIGH-WAVE DISPERSION ; LARGE IGNEOUS PROVINCE ; LOWER CRUSTAL FLOW ; UPPER-MANTLE STRUCTURE ; STRIKE-SLIP-FAULT ; TIBETAN PLATEAU ; ELECTRICAL-CONDUCTIVITY ; SE TIBET ; CONTINENTAL-CRUST ; STRUCTURE BENEATH
资助项目National Natural Science Foundation of China[91755215] ; National Natural Science Foundation of China[42074081] ; National Natural Science Foundation of China[42104071] ; Science Foundation of Chongqing[cstc2021jcyjjqX0018]
WOS研究方向Geology
语种英语
出版者SCIENCE PRESS
WOS记录号WOS:000785912100001
资助机构National Natural Science Foundation of China ; National Natural Science Foundation of China ; Science Foundation of Chongqing ; Science Foundation of Chongqing ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Science Foundation of Chongqing ; Science Foundation of Chongqing ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Science Foundation of Chongqing ; Science Foundation of Chongqing ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Science Foundation of Chongqing ; Science Foundation of Chongqing
源URL[http://ir.iggcas.ac.cn/handle/132A11/105119]  
专题地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者Yu, Nian; Wang, Xuben
作者单位1.Chongqing Univ, Sch Elect Engn, Chongqing 400044, Peoples R China
2.State Key Lab Coal Mine Disaster Dynam & Control, Chongqing 400044, Peoples R China
3.Chengdu Univ Technol, Dept Geophys, Chengdu 610059, Peoples R China
4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式
GB/T 7714		 Yu, Nian,Wang, Xuben,Li, Dewei,et al. The mechanism of deep material transport and seismogenic environment of the Xiaojiang fault system revealed by 3-D magnetotelluric study[J]. SCIENCE CHINA-EARTH SCIENCES,2022:18.
APA Yu, Nian.,Wang, Xuben.,Li, Dewei.,Li, Xin.,Wang, Enci.,...&Li, Tianyang.(2022).The mechanism of deep material transport and seismogenic environment of the Xiaojiang fault system revealed by 3-D magnetotelluric study.SCIENCE CHINA-EARTH SCIENCES,18.
MLA Yu, Nian,et al."The mechanism of deep material transport and seismogenic environment of the Xiaojiang fault system revealed by 3-D magnetotelluric study".SCIENCE CHINA-EARTH SCIENCES (2022):18.

入库方式： OAI收割

来源：地质与地球物理研究所

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