Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements
AbstractWe present the results of a magnetotelluric (MT) array across the Qilian orogenic belt to elucidate the uplift mechanism of the northeastern Tibetan Plateau (Qinghai-Tibet Plateau). The array extends from the Qaidam basin in the south to the southern edge of the Alxa block in...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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GeoScienceWorld
2022-10-01
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| Series: | Lithosphere |
| Online Access: | https://pubs.geoscienceworld.org/lithosphere/article/2022/1/5504977/618220/Deep-Electrical-Structure-of-the-Qilian-Orogenic |
| _version_ | 1811177423292596224 |
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| author | Jianqiang Kang Jiangtao Han Rui Gao Zhonghua Xin Lijia Liu Fanwen Meng |
| author_facet | Jianqiang Kang Jiangtao Han Rui Gao Zhonghua Xin Lijia Liu Fanwen Meng |
| author_sort | Jianqiang Kang |
| collection | DOAJ |
| description |
AbstractWe present the results of a magnetotelluric (MT) array across the Qilian orogenic belt to elucidate the uplift mechanism of the northeastern Tibetan Plateau (Qinghai-Tibet Plateau). The array extends from the Qaidam basin in the south to the southern edge of the Alxa block in the north. Using the three-dimensional (3D) inversion of MT data based on unstructured tetrahedral elements, the electrical structure 100 km below the orogenic belt is obtained. The results show that there are high-resistivity bodies in the lithospheric mantle of the North Qilian and Hexi Corridor, which may represent the trace of southward subduction of the Asian lithosphere. Besides, there are partially molten bodies with low resistivity in the middle and lower crust below the Qilian orogenic belt, which may be caused by tectonic heat. The melt fraction of low-resistivity bodies is 2-5%, which indicates that the crustal flow from the Qiangtang and Songpan-Ganzi blocks is unable to penetrate beneath the Qilian orogenic belt. The low-resistivity bodies beneath the Qilian orogenic belt decouples the upper crust from the middle-lower crust. Owing to the continuous compression, the decoupled middle-lower crust has subsequently driven the northward movement of the upper crust, resulting in the uplift of the Qilian orogenic belt. |
| first_indexed | 2024-04-11T06:02:44Z |
| format | Article |
| id | doaj.art-1fa9e6d5a28e443ca9c38f1fb9172ac0 |
| institution | Directory Open Access Journal |
| issn | 1941-8264 1947-4253 |
| language | English |
| last_indexed | 2024-04-11T06:02:44Z |
| publishDate | 2022-10-01 |
| publisher | GeoScienceWorld |
| record_format | Article |
| series | Lithosphere |
| spelling | doaj.art-1fa9e6d5a28e443ca9c38f1fb9172ac02022-12-22T04:41:36ZengGeoScienceWorldLithosphere1941-82641947-42532022-10-012022110.2113/2022/5504977Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral ElementsJianqiang Kang0http://orcid.org/0000-0002-3983-3275Jiangtao Han1http://orcid.org/0000-0002-9370-1409Rui Gao2Zhonghua Xin3Lijia Liu4Fanwen Meng51 College of Geoexploration Science and Technology Jilin University Changchun China jlu.edu.cn1 College of Geoexploration Science and Technology Jilin University Changchun China jlu.edu.cn3 School of Earth Geosciences and Engineering Sun Yat-sen University Guangzhou China sysu.edu.cn1 College of Geoexploration Science and Technology Jilin University Changchun China jlu.edu.cn1 College of Geoexploration Science and Technology Jilin University Changchun China jlu.edu.cn1 College of Geoexploration Science and Technology Jilin University Changchun China jlu.edu.cn AbstractWe present the results of a magnetotelluric (MT) array across the Qilian orogenic belt to elucidate the uplift mechanism of the northeastern Tibetan Plateau (Qinghai-Tibet Plateau). The array extends from the Qaidam basin in the south to the southern edge of the Alxa block in the north. Using the three-dimensional (3D) inversion of MT data based on unstructured tetrahedral elements, the electrical structure 100 km below the orogenic belt is obtained. The results show that there are high-resistivity bodies in the lithospheric mantle of the North Qilian and Hexi Corridor, which may represent the trace of southward subduction of the Asian lithosphere. Besides, there are partially molten bodies with low resistivity in the middle and lower crust below the Qilian orogenic belt, which may be caused by tectonic heat. The melt fraction of low-resistivity bodies is 2-5%, which indicates that the crustal flow from the Qiangtang and Songpan-Ganzi blocks is unable to penetrate beneath the Qilian orogenic belt. The low-resistivity bodies beneath the Qilian orogenic belt decouples the upper crust from the middle-lower crust. Owing to the continuous compression, the decoupled middle-lower crust has subsequently driven the northward movement of the upper crust, resulting in the uplift of the Qilian orogenic belt.https://pubs.geoscienceworld.org/lithosphere/article/2022/1/5504977/618220/Deep-Electrical-Structure-of-the-Qilian-Orogenic |
| spellingShingle | Jianqiang Kang Jiangtao Han Rui Gao Zhonghua Xin Lijia Liu Fanwen Meng Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements Lithosphere |
| title | Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements |
| title_full | Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements |
| title_fullStr | Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements |
| title_full_unstemmed | Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements |
| title_short | Deep Electrical Structure of the Qilian Orogenic Belt with Dynamic Implications for the Northeastern Margin of the Tibetan Plateau: Revealed by 3D Magnetotelluric Inversion Using Unstructured Tetrahedral Elements |
| title_sort | deep electrical structure of the qilian orogenic belt with dynamic implications for the northeastern margin of the tibetan plateau revealed by 3d magnetotelluric inversion using unstructured tetrahedral elements |
| url | https://pubs.geoscienceworld.org/lithosphere/article/2022/1/5504977/618220/Deep-Electrical-Structure-of-the-Qilian-Orogenic |
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