The Study Of Magnetotelluric Sounding "Standard Site" In South China Lithosphere

South China is located in Eurasia edge,impacted by the collision of the Indian plate and the Pacific plate subduction squeeze,while the small scale Lithospheric craton and low degree of consolidation,form of today's complex material composition and a variety of structural forms.This paper relying on SinoProbe-01 in South China"Standard Network" Magnetotelluric Sounding to carry out.As one of the Geological studies hot spots in South China in geology and geophysics,although have made many achievements,there still have many problems to be solved,so using 4°×4°Magnetotelluric Sounding of the "Standard Network" data for research will benefit for the study of South China Lithosphere structure from the electrical views.How to use an innovative way of Magnetotelluric observations-"standard point",study on the South China Lithospheric-scale electrical structure are the guiding ideology and the ultimate goal of this paper.Firstly,the paper studies on the theoretical model that observered with "Standard Point",and introduction of the resistivity weighted fusion algorithm to construct a weighted resistivity fusion model.Subsequently,using South China 8 "Standard point" data do two-dimensional and three-dimensional inversion and constructed weighted fusion models,combine with geological and geophysical results discussed this models.Finally,analysis the crust high conductivity layer formation mechanisms in South China using "Standard Point".By the paper research,we can get the conclusions:The standard model should be a complicated,complex model that includes the "Standard Point" feature apparent resistivity phase frequency response curve,the two-dimensional inversion models,three-dimensional inversion models and weighted fusion model and many other auxiliary models,these models constitute a diverse,multi-angle composite model to explain as much as possible underground electrical structure,in that way called the composite model as standard model.High-conductivity layer formed in each"Standard Point" may be the result of both filling of fluid and partial melting of rocks(temperature),but the dominant factor have some differences under different geological backgrounds.The 11623 "standard point" which in Cathaysia Massif and offshore,without the high-conductivity layer crust.Its electrical structure model showing the influence of the westward subduction of the Pacific plate.The paper gives the evidences of the structure detachment(high-conductivity layer)at the Long Men Shan fault and continental collision's wedge structure.Proved the high-conductivity layer position in Dabie orogenic belt crust consistent with the seismic velocity disconnected profile and the gravity of the low-density areas,which may be due to the subduction of the Yangtze block led to the enrichment of water and the partial melting of rocks.