1. Lithospheric electrical structure and its implications for the evolution of the middle Qinling Orogenic Belt, Central China: Constraints from 3-D magnetotelluric imaging.
- Author
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Liang, Hongda, Gao, Rui, and Xue, Shuai
- Subjects
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MAGNETOTELLURICS , *OROGENIC belts , *THREE-dimensional imaging , *ELECTRICAL resistivity - Abstract
The Qinling Orogenic Belt is located at the central part of the China Central Orogenic Belt and links the Qilian and Kunlun Orogenic Belts to the west with the Dabie-Sulu Orogenic Belt to the east, which is sandwiched between the South China Block and North China Block. There have been several geodynamic models developed to explain the evolution process of the Qinling Orogenic Belt, but they remain controversial. The magnetotelluric (MT) method can study subsurface electrical structures. In order to have a better understanding of the tectonic evolution of the Qinling Orogenic Belt, a study of broadband and long period MT profile across the middle Qinling Orogenic Belt is carried out. The MT profile starts from the northeastern margin of the Sichuan basin, crosses the Qinling, and finally reaches the Weihe basin at about 108.5°E. Based on data analysis results, we have finally obtained a lithospheric electrical resistivity model of the middle Qinling Orogenic Belt through three-dimensional (3-D) inversion of magnetotelluric data. The MT result reveals that the Sichuan and Weihe basins may have remnants of the ancient craton basement in our study area. The electrical structure characteristics of the South Qinling Belt and North Qinling Belt are obviously different, the South Qinling Belt is relatively low resistivity, while the North Qinling Belt is relatively high resistivity. This may indicate that the Southern Qinling Belt is affected by the later strike slip extrusion and the Northern Qinling Belt is a relatively stable block. The lithospheric mantle of middle Qinling Orogenic Belt is characterized by overall high resistivity, which may indicate that the lateral extrusion effect of the Tibetan Plateau material is negligible in this region. • Lithospheric electrical structure of the middle Qinling Orogenic Belt was obtained from 3-D inversion of MT data. • The Southern Qinling is affected by the strike-slip fault and the Northern Qinling is a relatively stable block. • Lithospheric mantle is not greatly affected by the eastward extrusion of the Tibetan Plateau. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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