Deep electrical resistivity structure across the Gyaring Co Fault in Central Tibet revealed by magnetotelluric data and its implication

Mapping of Fault and Hydrothermal System beneath the Seulawah Volcano Inferred from a Magnetotellurics Structure

“…The measurement was conducted in a regional scale, including investigation of the tectonics, where the applied distances between sites were varied between 5 to 10 km. This is similar to the volcano-tectonic mapping of the Southern Andes, Chile, that used distances between stations of ±5 km [51] and the studies on the structure of fracture in Central Tibet with the distances between stations ±10 km [52]. Meanwhile, in the small study area, the MT method was measured with the distance between sites varying from 1 to 5 km.…”

北喜马拉雅错那洞穹窿深部三维电性结构及其构造意义

“…In this model, in conjunctioncombined with the concentrated denudation of the surface, the southward channel flow (or crustal flow) led to the development of the STDS and the NGHD as well as the exposure of granite in the Northern Himalayas. The widely distributed weak mid-to-lower crusts in the plateau and the outward crustal flow are supported by numerous dynamic simulations and geophysical data Unsworth et al, 2004Unsworth et al, , 2005Zhao et al, 2012;Wang et al, 2018;Pang et al, 2019;Yu et al, 2020;Sun et al, 2020;Xue et al, 2021). In additionMoreover, an increasing number of studies indicate that the NHGD may result from complex tectono-magmatic activities and different deformation processes rather than a single model (Lee et al, 2000(Lee et al, , 2006Zhang, 2007;Zhang et al, 2012;.…”

“…Therefore, the magnetotelluric (MT) method is utilizedused to study structures beneath the Cuonadong dome in the Northern Himalayas, which is sensitive to fluids (saline fluids, partial melting, etc.) and is popularly used to explorestudy the resistivity structures of cratons and Tibetan Plateau where there a weak mid-to-lower crust is present (Unsworth et al, 2004(Unsworth et al, , 2005Wang et al, 2018;Ye et al, 2018;Jin et al, 2010;Xu et al, 2019;Chen et al, 2019;Hu et al, 2020;Yu et al, 2020;Xue et al, 2019Xue et al, , 2021. The Cuonadong dome is a newly discovered dome with rare-metal mineralization of beryllium (Be), polymetallic mineralization (lead-zinc (Pb-Zn), and gold-antimony (Au-Sb)), showing significant metallogenic potential Zhang et al, 2018;Xia et al, 2019;Liang et al, 2019Liang et al, , 2020.…”

“…Therein, the STDS is the largest normal fault system in the world, in which the low-grade metamorphic sedimentary rocks in the Tethyan Himalayas are directly superimposed over the high-grade metamorphic crystalline rocks in the High Himalayas Zhang, 2007;Wang et al, 2016). The NSTR is mainly composed of seven rifts that are regularly distributed from west to east, whose southern end usually cuts the STDS while the northern end extends to the Lhasa block or further Zhang et al, 2007Zhang et al, , 2012Xue et al, 2021). The NHGD is mainly placed in the Northern Himalayas and lies near the STDS.…”

“…Before MT data were used to employfor inversions, the dimensionality of the subsurface structure needs to be evaluated for judgingdetermining whether a 2D or 3D approach is more appropriate: because ofdue to the advantages on avoiding the effect of galvanic electric field and no prior dimensionality assumption, the phase tensor decomposition method is popularly used in studyinganalysing the dimensionality of the subsurface structure and the preference direction of underground current. (Hill et al, 2009;Xiao et al, 2013;Meqbel et al, 2014Meqbel et al, , 2016Zhang et al, 2016;Xue et al, 2019Xue et al, , 2021. The MT phase tensors are generally expressed as a series of ellipses, whose long axis and short axis are used to reflectindicate lateral variations of underground electrical resistivity structures.…”