Detailed Electrical Structure Characteristics And Tectonic Implications Of The Qinzhou Bay-Hangzhou Bay Juncture Belt And Adjacent Area

This paper relies on the observation of the magnetotelluric array of the Qinzhou Bay-Hangzhou Bay juncture belt and the survey of the electrical structure of the crustal crust No1 and No3 survey line,as well as the observation of the large-earth electromagnetic surveying section and the three-dimensional electrical structure study of the crust and mantle.No.6 and No.8 geomagnetic sounding data.established Two sections of the NE 120° magnetotelluric sounding profile.The data was processed by methods such as Robust estimation,remote reference processing,and artificial power spectrum selection.The phase tensor elliptic analysis obtained the electrical structure of the underground dielectric in the study area as a whole as two-dimensional.The electrical main axis azimuth is obtained by impedance tensor decomposition as NE35°.A large number of inversion experiments have obtained the best inversion model and inversion parameters.The depth of the inversion model was tested and analyzed,and it is believed that the inversion model has a certain degree of feasibility within a depth of 150 km.The results show that the longitudinal stratification of the crust-mantle electrical structure model in the study area is not obvious,and the lateral zone has good blockiness.Five regional deep fault zones have been identified by the electrical gradient zone and low-resistance dividing the block,Among them,Yifeng-Jingdezhen fault,Pingxiang-Guangfeng fault,Zhenghe-Dabu fault,and three lithospheric faults divide the study area into the Yangtze block,the Qinzhou Bay-Hangzhou Bay juncture belt,the Cathaysian fold belt,and the southeastern coastal magmatic belt.The high resistivity of the shallow and middle-upper crusts of the southeastern margin of Yangtze block is a crystalline basement of the Precambrian.The deep low resistance is a strongly lithospheric mantle;the Qinzhou Bay-Hangzhou Bay juncture belt presents a mediumhigh resistance,the shallow and middle-upper crusts are the metamorphic basement,may be in the deep part of the ancient lithosphere;the shallow and middle-upper crust of the Cathaysian fold belt are ultra-high resistance magmatic rocks,and the deep high resistance is the lithospheric mantle and the lithosphere destacking accumulation;The uplift of the low-resistance layer of the deep mantle in the southeastern coastal magmatic rock belt is presumed to reflect the thinning of the lithosphere.The metallogenic periods in southeastern South China were mainly concentrated in the Yanshanian period,and the metallogenesis was closely related to the magmatic activities.The mineralization of important ore deposits and ore clusters is closely related to the near-steep low-resistance anomaly belts.The ore-forming processes in most of the deposits in the Jiangxi central of the Wugongshan metallogenic belt and the Fujian west of Wuyishan metallogenic belt in are related to deep mantle-derived materials.There is a good correspondence between the electrical structure model and the crust-mantle-scale magmatic-fluid-mineralization system.The majority of oreforming processes in the Qinzhou Bay-Hangzhou Bay juncture belt and adjacent areas are affected by the system.