Huainan-Liyang Geological Corridor Magnetotelluric Data Processing And Inversion Interpretation Research

This paper uses the V5-2000muti-fuction electrical instrument to carry out the magnetotelluric observation in the huainan—liyang large section.By using the advanced magnetotelluric processing and interpretation technology and analysising the huainan—liyang profile,we get more credible huainan—liyang profile electrical structore,at the same time,we study the previous work and fully utilize the advantages of magnetotelluric sounding.with the above work, huainan—liyang section were understood.This paper firstly reviewed the research situation of deep exploration and recognized the significance og carrying out deep exploration.At the same time,we also know that the magnetotelluric method in deep exploration is an effective geophysical method.According to the requirements of the project,we arranged a measured line in the middle and lower reaches of Yangtze River.The measured line north west start at the Anhui Dingyuan,through the Ma anshan,south east arrived in Jiangsu Liyang.The measured line across a number of tectonic units.We completed a total of MT sounding point61and the dot pitch is5Km.After the careful choice of site and standardize operations,we obtained high quality data.the data collected on the field did further de-noising processing through the impedance estimate、selection of power spectrum、remote reference and other means.Secondly,we studied the tectonic units which the measured line across (the North China plate、along the Yangtze River frame belt、 Yangtze craton) and we analyzed the parameter such as impedance tensor polarization ellipse、two dimensional deviation、tipper、apparent resistivity and phase curves, we draw the following conclusions (1)the test area shallow bias in two dimensional structure and deep geological structure is complex.(2)tipper can be used in judging electrical structure transverse mutation and finding frature location.(3)the electrical changes in the North China plate are more gentle and the electrical changes in the along the Yangtze River frame belt are more severe. The paper give a brief introduction to the principles of the occam inversion,nonlinear conjugate gradient inversion and continuous medium inversion,we process a comparative study of these three inversion methods by the calculation of the typical theoretical models.At last,we choose the continuous medium inversion with TE and TM mode to deal with the huainan-liyang data.with this method,we get the two-dimensional electronic structure diagram,the two picture have the depth of10Km and50Km.Finally,with the comprehensive analysis of the apparent resistivity and phase curves cross section diagram、the electronic chart of the two-dimensional inversion and geological map of huainan-liyang,we completed a comprehensive interpretation to the electric structure of the region.