AMT在文山某沉积型铝土矿勘查中地质地球物理模型建立与探讨

The discussion of geological and geophysical model establishment in the exploration of a sedimentary bauxite deposit in Wenshan by AMT method

以文山某沉积型铝土矿勘查为目的,采用音频大地电磁法(AMT),总体勾勒AMT测深针对沉积型铝土矿的勘查思路,详细阐述了AMT的数据处理手段。首先在该矿区已知地质剖面上进行了可行性试验研究,根据试验剖面的效果,结合矿区岩性地球物理特征及地质情况,建立了矿区地球物理找矿模型,进而在矿区布设了4条AMT测线。通过AMT测深剖面,并结合地质对深部沉积型铝土矿的富集部位进行了推测与空间定位。经钻孔验证,证实了沉积型铝土矿的存在及深部的延伸。结果表明:沉积型铝土矿相对围岩显示为低阻高极化特征。应用AMT测深,结合地质进行推断解释,能够有效探测沉积型铝土矿空间延伸情况。通过该应用与探讨为该区沉积型铝土矿勘查提供了思路和方法选择依据,为铝土矿勘查提供借鉴。

In this paper,audio frequency magnetotelluric method(AMT)is adopted for the exploration of a sedimentary bauxite deposit in Wenshan,and the exploration idea of AMT measurement in the sedimentary bauxite is outlined in general,and the data processing method of AMT is described in detail.First of all,the feasibility test study is carried out on the known geological profile in the mining area.According to the effect of the experimental profile and with the combination of the lithological and geophysical characteristics and geological conditions of the mining area,the geophysical prospecting model of the mining area is established,and then four AMT survey lines are set up in the mining area.The spatial extension of sedimentary bauxite can be effectively detected by the application of AMT measurement and geological inference and interpretation.The existence and deep extension of sedimentary bauxite is verified by drilling work.The result shows that the sedimentary bauxite relative to the surrounding rock is characterized by low resistance and high polarization features.Through this application and discussion,the thought and method selection basis is provided for sedimentary bauxite exploration,and a reference is also provided for bauxite exploration in this area.