Identification and Application of Audio Magnetotellurics to the Deep Buried Structure:A Case Study of Lijiawan Manganese Deposit at Songtao County in Guizhou Province

Songtao manganese mine integrated exploration zone belongs to a part of the national integrated exploration area.Facing the present situation of difficulty in deep prospecting,the buried structure identification for second space(depth from 500 to 2000meters)is very important.For the study of preservation conditions of current manganese deposit,it is necessary to recognize the deep buried structure by AMT.In this paper,with the physical properties in this area as the foundation,combined with 'Datangpo type' manganese deposit model,we established the initial geoelectric forwarding model,and then,calculated the forward computation curves of TE and TM mode.By contrast,we found that the TM mode outperforms the TE mode in the vertical resolution.Also we compared the response characteristics of the two curves in the hanging walls and footwalls of the fault.Through the different inversions of real data in Lijiawan manganese deposit,it can better reflect the morphology when NLCG-TE inversion,whose initial model is Occam-TE data measure the geoelectric section.Finally,the electric profile analysis of the structural characteristics provides geophysical evidence for the identification of deep buried structure and the extent of damage about a series of strata with manganese,also offers reference for deployment of deep exploration.