气候变化领域集成服务门户(CCPortal): Lithospheric electrical structure beneath the Cathaysia Block in South China and its tectonic implications

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DOI	10.1016/j.tecto.2021.228981
	Lithospheric electrical structure beneath the Cathaysia Block in South China and its tectonic implications
	Cheng Y.; Han B.; Li Y.; Guo J.; Hu X.
发表日期	2021
ISSN	00401951
卷号	814
英文摘要	To better constrain the heat source of the geothermal system and lithospheric thinning mechanism of the Paleo-Pacific subduction zone, data from 35 broadband magnetotelluric (MT) stations were collected in 2020 along a 180-km-long NW-trending profile in the Cathaysia Block. Based on the measured data, we obtained the lithospheric electrical structure of the Cathaysia Block in South China using the 3D MT inversion code of ModEM. The final resistivity structure along the profile shows a series of highly conductive anomalies and highly resistive anomalies. The highly resistive anomalies in the upper crust correspond well with the distribution of magmatic rocks, which extend downwards to depths of 20 km. The highly resistive anomalies with a depth of 20–40 km are interpreted as crustal mafic sills derived from the mantle. The crustal conductors at depths of 5–15 km are typically interpreted as accumulations of aqueous fluids, which originate from the dehydration of the slab during the flat-slab subduction of the Paleo-Pacific Plate and are confined in the crust by impermeable layers. Fluid fractions of 0.8–9% would be required to explain the observed conductance values. The MT results indicate that there is no magma chamber or partial melt beneath the geothermal system. Therefore, the heat source of the geothermal system in the Cathaysia Block is radiogenic heat produced by the decay of radioactive elements in the crust. Thermal erosion has played a central role in lithospheric thinning and crust–mantle interaction of the Cathaysia Block. © 2021 Elsevier B.V.
关键词	Electrical structure Hydrothermal fluid Lithospheric thinning Magnetotellurics South China
英文关键词	Radioactive elements; Broadband magnetotelluric; Crustal conductors; Electrical structures; Flat-slab subductions; Lithospheric thinning; Paleo-Pacific subductions; Resistivity structure; Tectonic implications; Geothermal fields; electric field; electrical resistivity; geothermal system; heat source; hydrothermal fluid; lithospheric structure; magnetotelluric method; plate tectonics; subduction zone; tectonic structure; Cathaysia Block; China
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207958
作者单位	Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China; Institute of Geological Survey, China University of Geosciences, Wuhan, 430074, China; Wuhan SYZKer Technology Company, 19 Beitucheng Xi Lu, Chaoyang District, Beijing, China; Key Laboratory of Subsurface Multi-Scale Imaging, Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, 430074, China
推荐引用方式 GB/T 7714	Cheng Y.,Han B.,Li Y.,et al. Lithospheric electrical structure beneath the Cathaysia Block in South China and its tectonic implications[J],2021,814.
APA	Cheng Y.,Han B.,Li Y.,Guo J.,&Hu X..(2021).Lithospheric electrical structure beneath the Cathaysia Block in South China and its tectonic implications.Tectonophysics,814.
MLA	Cheng Y.,et al."Lithospheric electrical structure beneath the Cathaysia Block in South China and its tectonic implications".Tectonophysics 814(2021).