AMT法勘查贵州铝土矿

An analysis of the effect of the audio magnetotelluric method(AMT)in the exploration of bauxite deposits in Guizhou

贵州铝土矿资源储量丰厚,分布面广,但多为隐伏型沉积型矿,仅有的易辨别、易发现的地表或浅层铝土矿已经开发殆尽,在此开展隐伏铝土矿的物探方法试验研究对今后勘查工作具有重要的指导意义。本文简要介绍了AMT基本工作方法以及贵州金沙长沟工区的地质和地球物理特征,重点讨论了AMT在长沟工区铝土矿勘查中的应用效果,通过对电阻率断面图的综合推断解释,划分出了二叠系、石炭系、寒武系之间地层界面,圈出了含矿有利部位。经钻孔验证,取得了较好的找矿效果。

Guizhou has rich and extensively distributed bauxite resources,but bauxite deposits there are mostly concealed sedimentary ones. The easily-discovered shallow and surface bauxite deposits have almost been totally exploited,and hence the experimental test of geophysical methods in search for concealed bauxite deposits is of great significance for further ore-prospecting work. In this paper,the authors describe in brief the basic working procedure of the AMT method as well as geological and geophysical characteristics of the Changgou work area in Jinsha district,Guizhou Province,and emphatically discuss the application results of AMT in the bauxite exploration of Changgou work area. Based on integrated inference and interpretation of the resistivity section,the authors recognized the stratigraphic boundaries between Permian,Carboniferous and Cambrian,delineated favorable ore-bearing places,and attained fairly good ore-prospecting results,as demonstrated by later drilling verification.