The Use Of Magnetotelluric In AEM Ground Investigate And Verify

In this paper we test the maggnetic anomaly in GeShuoshan city of Inner Mongolia province–ShiZuishan city of Ningxia province areas.And the multifunction electrical method instrument v8 has been used which is made by Canada phoenix company.Introducing the advanced data processing method and interpretation technology,we did a research on the electromagnetic (AMT/MT) profile data to get some credible electrical structure in that regional crust. Combining the previous research achievements and taking the advantages of MT method, we discussed the magnetic anomaly of the region and obtained some useful conclusions.Firstly,we introduces the geophysical and geological conditions in the area of GeShuoshan city of Inner Mongolia province–ShiZuishan city of Ningxia province. And then we analyzed and described the gravity and maggnetic anomaly.Secondly we introduces the basic principle of MT sounding method and the signal features of the natural source field.In addition,the process flow of the MT signal data is briefly introduced.One of the key points of this paper is the qualitative analysis and interpretation for the profile data. Research on the characters of underground electrical structure is available by analysising the electrical sounding curve. Bostik method is based on properties of the magnetotelluric sounding asymptote curves in low frequency and alternate the apparent resistivity changing with periodic to the true resistivity curve that changing with depth. According to extreme value point's position of the transformed curve,we can also roughly define the depth of the interphase.This method is of simple formula,rapid inversion and directly revealed the electrical structures of underground. Then we analysis the results of the collect data after Using Bostik transform method,and the main electrical characteristics of the structure have been studied。This provides a foundation for the interpretation of the profile.For the selection of inverse method, the thesis introduces several common inverse methods and mainly adopts one-dimension Occam inverse method and two-dimension NLCG inverse method for the purpose of processing data in the direction of cross-section, acquiring the earth's crust two-dimension conductivity structure.Taking the two-dimensional electrical structure as the key point and combining the result of 2D inversion,considering the regional gravity, magnetic anomal characters, we analyzed the structure and magnetic anomaly in this area and deduced three faults,two of which are consistent with the known fact. In this paper,We have deduced the position of the magnetic anomaly body which was consistent with the location of anomaly body center. We estimated that it was the important factor of this regional magnetic anomalies.Having the regional geological and geophysical data as the background, combinating the regional abnormalities,we foreseed the future of this mineral resources in the area in the end.