陡倾型隐伏金属矿勘查关键

The Key to Exploration of Steeply-Dipping Concealed Metal Deposits

以往陡倾型金属矿勘查钻孔的见矿率较低,查找无矿钻孔出现的原因及提高钻孔见矿率成为陡倾型隐伏金属矿勘查的关键。本次通过陡倾型隐伏铜矿的勘查,对陡倾型隐伏金属矿的无矿钻孔出现的原因进行分析,以期有助于以后陡倾型金属矿床的高效勘查。根据岩矿石的物性特征,选择激电中梯、激电测深综合物探方法,进行钻探验证,分析发现无矿钻孔主要是由矿体倾向发生反转和矿化不均一两种原因造成的。建议在分析确定好作为物探资料解译约束条件的深部金属矿体物性特征的前提下,选择适宜的电法、磁法、重力等地球物理扫面和测深综合物探方法进行陡倾型隐伏金属矿的前期勘查,主要利用附近钻孔有无矿化或利用物探测深的矿致异常有无间断来判断矿体矿化是否均一,利用物探扫面矿致异常的位置或附近钻孔钻遇的矿体倾向特征及井中物探来判断矿体倾向是否发生反转。另外,为提高陡倾型隐伏金属矿钻孔见矿的可能性,建议多施工一些倾角较小的钻孔。

In general the successful rate of exploration drilling at steep-dipping metal deposits is relatively low.Finding out the reason for no-ore occurrence drilling thus enhancing the percentage of ore-occurrence drill holes is the key to the exploration of such metal deposits.This paper addresses this issue by analyzing a case of exploration on a hidden copper deposit with steep dip.The analysis builds on the physical characteristics of the rock and ore,integrated geophysical prospecting of induced-polarization(IP)middle ladder and IP sounding and drilling verification.Results reveal that the inversion of the ore body dipping direction and the heterogeneity of mineralization are two primary factors responsible for the failure of exploration drilling.It is recommended to select suitable electrical,magnetic,gravity and other geophysical scanning and sounding methods to perform surveys in the early stage of exploration under the premise of determining the physical characteristics of deep metal ore bodies as constraints for the interpretation of geophysical data.The preliminary exploration of metal ore mainly judges whether the mineralization of the ore body is uniform or not based on whether there is mineralization in nearby boreholes or whether there is a discontinuity in deep ore-induced anomalies.Meanwhile according to the location of the ore-induced anomalies on geophysical prospecting profiles or ore body dipping features in nearby drilling holes and geophysical prospecting in wells,the judgement is made whether the tendency of the ore body is reversed.In addition,in order to increase the possibility of ore occurrence in drilling holes in steeply inclined concealed metal mines,it is recommended to construct more drilling holes with smaller inclination angles.