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DOI	10.1016/j.epsl.2020.116493
	A plume-modified lithospheric barrier to the southeastward flow of partially molten Tibetan crust inferred from magnetotelluric data
	Li X.; Ma X.; Chen Y.; Xue S.; Varentsov I.M.; Bai D.
发表日期	2020
ISSN	0012821X
卷号	548
英文摘要	Broadband and long-period magnetotelluric (MT) data were used to obtain a continuous image of the lithospheric electrical conductivity structure across the southeastern Tibetan Plateau margin, where long-wavelength crustal thickening and surface uplift have been attributed to the influx of weak crustal material from Tibet into the adjacent Yangtze Block. The resulting resistivity model reveals two major conductive features in the middle–lower crust beneath southeastern Tibet and the Chuxiong basin, both of which are consistent with the presence of fluids and likely enhanced by shear deformation along large faults. The horizontally extensive conductor beneath southeastern Tibet could be interpreted as a partially molten layer that represents topography-driven crustal flow from central Tibet, whereas the anomalously high conductivities observed beneath the Chuxiong basin require the addition of substantial amounts of saline aqueous fluids. These two conductors are separated by a lithospheric-scale, high-resistivity body that situated beneath the geologically inferred core of the Emeishan large igneous province (ELIP). Together with other geophysical and geological evidence, we interpret this anomaly as remnants of a plume-modified lithosphere that originally formed during the Permian Emeishan volcanism, and speculate it acts as an obstruction to the southeastward crustal flow from Tibet since Late Cenozoic. These results indicate that topography-driven crustal flow may contribute to crustal thickening and uplift in southeastern Tibet, but not in the adjacent foreland. Instead, magmatic underplating associated with the Permian plume activity could account for both the elevated topography and thickened crust of the adjacent Yangtze Block without the need for crustal flow. © 2020 Elsevier B.V.
关键词	crustal flow electrical conductivity Emeishan mantle plume magmatic underplating magnetotellurics southeastern Tibetan Plateau margin
英文关键词	Magnetotellurics; Crustal materials; Crustal thickenings; Electrical conductivity; Emeishan large igneous provinces; High conductivity; High resistivity; Magnetotelluric data; Resistivity modeling; Topography; crustal structure; crustal thickening; electrical conductivity; large igneous province; lithospheric structure; magnetotelluric method; mantle plume; China; Chuxiong Basin; Qinghai-Xizang Plateau; Xizang; Yangtze Platform; Yunnan
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202727
作者单位	State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China; Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China; Geoelectromagnetic Research Center, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russian Federation
推荐引用方式 GB/T 7714	Li X.,Ma X.,Chen Y.,et al. A plume-modified lithospheric barrier to the southeastward flow of partially molten Tibetan crust inferred from magnetotelluric data[J],2020,548.
APA	Li X.,Ma X.,Chen Y.,Xue S.,Varentsov I.M.,&Bai D..(2020).A plume-modified lithospheric barrier to the southeastward flow of partially molten Tibetan crust inferred from magnetotelluric data.Earth and Planetary Science Letters,548.
MLA	Li X.,et al."A plume-modified lithospheric barrier to the southeastward flow of partially molten Tibetan crust inferred from magnetotelluric data".Earth and Planetary Science Letters 548(2020).