气候变化领域集成服务门户(CCPortal): Three-dimensional magnetotelluric imaging of the SE Gonghe Basin: Implication for the orogenic uplift in the northeastern margin of the Tibetan plateau

CCPortal

DOI	10.1016/j.tecto.2020.228525
	Three-dimensional magnetotelluric imaging of the SE Gonghe Basin: Implication for the orogenic uplift in the northeastern margin of the Tibetan plateau
	Gao J.; Zhang H.; Zhang H.; Zhang S.; Cheng Z.
发表日期	2020
ISSN	00401951
卷号	789
英文摘要	To better understand the upper crustal shortening and orogenic uplift in the northeastern margin of the Tibetan Plateau, we have utilized magnetotelluric (MT) data at 116 sites along two lines around the SE Gonghe Basin to determine a three-dimensional (3D) resistivity model by a 3D MT inversion package ModEM. Our resistivity model reveals a significant feature of step discontinuities between high and low resistivity blocks at different depths in the upper and middle crust. These discontinuities correspond well with the sharp topography variations, thus showing clear tendencies to be the thrust faults beneath the Gonghe Basin responsible for the formation of Gonghe Nan Shan (GHNS) thrust belt. Our 3D resistivity model also shows a large higher resistivity body at depths of 3–10 km located beneath the hot springs around the Basin. We interpreted this anomaly as resistive granite body, which acts as hot dry rocks (HDRs) to generate heat for the hot springs on the surface. Our results also reveal a pronounced conductive layer at depths of 10–25 km in the middle-upper crust, which is most likely caused by partial melting for heating the above HDRs. This high conductivity layer would behave in a ductile regime near the bottom of the high resistivity body and act as a decollement for the crustal shortening and deformation in the northeastern margin of the Tibetan Plateau. © 2020 Elsevier B.V.
关键词	Conductive layer in the middle crust Crustal shortening and orogenic uplift Gonghe Basin Magnetotelluric imaging Northeastern Tibetan plateau
英文关键词	Faulting; Hot springs; Magnetotellurics; Springs (components); Topography; Conductive layer; Crustal shortening; High conductivity; High resistivity; Magnetotelluric imaging; Resistivity modeling; Step discontinuity; Threedimensional (3-d); 3D modeling; crustal shortening; decollement; deformation mechanism; electrical resistivity; magnetotelluric method; orogeny; partial melting; three-dimensional modeling; thrust fault; uplift; upper crust; China; Gonghe Basin; Qinghai; Qinghai-Xizang Plateau
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/207756
作者单位	Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; Mengcheng National Geophysical Observatory, University of Science and Technology of China, Hefei, Anhui, China; State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing, China; Center for hydrogeology and environmental geology survey, China Geological Survey, Baoding, China
推荐引用方式 GB/T 7714	Gao J.,Zhang H.,Zhang H.,et al. Three-dimensional magnetotelluric imaging of the SE Gonghe Basin: Implication for the orogenic uplift in the northeastern margin of the Tibetan plateau[J],2020,789.
APA	Gao J.,Zhang H.,Zhang H.,Zhang S.,&Cheng Z..(2020).Three-dimensional magnetotelluric imaging of the SE Gonghe Basin: Implication for the orogenic uplift in the northeastern margin of the Tibetan plateau.Tectonophysics,789.
MLA	Gao J.,et al."Three-dimensional magnetotelluric imaging of the SE Gonghe Basin: Implication for the orogenic uplift in the northeastern margin of the Tibetan plateau".Tectonophysics 789(2020).