Application And Study Of Controlled Source Audio-frequency Magneto Tellurics In Deep Structure Of Huogeqi Mining Area

This paper is based on Huogeqi integrated exploration project in Wulathou Banner,Inner Mongolia Autonomous Region.Through field survey,it is found that the topography in the research area fluctuates greatly,and there are more waste piles and tailings piles,which make it more difficult to collect data.The electromagnetic interference in the study area is relatively large,mainly including high-voltage lines and underground pipelines,etc.If not handled properly,the quality and accuracy of electromagnetic signals will be affected.Based on the advantages of CSAMT,such as strong anti-interference ability,high working efficiency,little influence by terrain,high horizontal resolution,etc.,it is decided to carry out CSAMT measurement under the complicated conditions of Huogeqi.In actual work,measures such as increasing emission current,increasing frequency superposition times and data acquisition time are adopted to improve data quality and accuracy.On the basis of collecting and reading CSAMT prospecting cases and related documents,this paper briefly introduces the theory and practical working methods of this method,and makes a detailed study on the selection of parameters and matters needing attention in the field construction of CSAMT,focusing on the determination of transceiver distance,the layout of AB field source and the feasibility of this method in the research area according to the forward modeling results of the initial model.At the same time,the modeling forward modeling of typical apparent resistivity curves and the processing and inversion of field data are studied and analyzed.A total of 1 CSAMT sounding profile and 138 geophysical survey points have been completed in the study area.It can be seen from CSAMT bathymetric inversion and inferred interpretation section map of ZP650 line that the abnormal features are clear,the deep underground structure is complete and continuous,and the extension of the fault structure on the ground corresponds well to the development position of the structural belt on the geological map.It can be roughly inferred that Huogeqi No.1 and No.2 orebodies are obviously controlled by the structure,which provides geophysical basis for the assumption of compound fold control.In the later period,geophysical and geochemical exploration work can be carried out on the two wings of folds in a targeted manner,which provides a reference for the later prospecting direction in the survey area.To sum up,CSAMT can be well applied to find fault structures in the exploration area under the complex geology and strong human interference.This success story can also be extended to similar research areas.In controlling deep structures,this method is obviously better than the conventional direct current bathymetry in depth exploration,construction efficiency and resolution,depending on its strong anti-interference ability and high working efficiency.The CSAMT survey results are credible and effective,which can guide the exploration of deep structures in a larger range around the survey area and play an indirect role in prospecting.