Three-dimensional Electrical Structures And Significance For Mineral Exploration In Jiujiang-ruichang District

Jiangxi Jiurui area, which is located in the Yangtze River metallogenic belt, is one of the national key ready exploration area and also is an important lead-zinc copper gold collection area.Years of geological exploration and scientific research has proven that the Yangtze metallogenic belt resources with a broad perspective have enormous exploration potential, its deep prospecting work has been a research focus and the study of the electrical characteristics of underground structures in the region of the Yangtze River to find mine is significant.In this paper, relying on the “Twelfth Five-Year Plan” National Science and Technology Support Project “ three-dimensional detection of Ore-controlling strata, rockmass and the research of Prospecting prediction in Jiurui ore concentration area of Jiangxi province(No. 2011BAB04B03)”, according to the measured data of the audio magnetotelluric sounding profiles in Jiurui region and this paper make some researches.Based on the comprehensive theoretical analysis of geological data, rock samples and the typical formation resistivity parameter test, we carried out the research on three-dimensional structure of underground electrical in the study area by making use of the AMT data.In order to obtain the best AMT inversion parameters, with the help of the three typical profile AMT experimental study of nonlinear conjugate gradient inversion(NLCG), it is summed up that the two-dimensional inversion scheme of TM polarization mode data and Lagrange multipliers equalling to three can achieve better results. Though the utilization of geology, drilling and electrical characteristics of AMT constrained inversion of the region's 23 two-dimensional profiles, then a three-dimensional electronic structure of the study area can be obtained by gridding all the three-dimensional resistivity inversion profiles.Finally, analyzing the three-dimensional structure of electricity, we determine subsurface formations, rock distribution, distribution of faults and basement relief situations.By comparison with the known deposits, the results show that the favorable metallogenic areas exist in the interchanges of the shallow north-west regional fracture and deep north-east fracture as well as near the edge of the groove and the basement uplift magma conduit.