物探激电测深对盲矿体的预测必须以地质条件为前提,而合理的地质解译又是成矿预测的关键.下蒿坪金矿矿产资源保有量不足,矿区内的F40断裂带宽80~200m,地表露头矿化极弱.测试表明,本区的矿岩物性差异明显,选用对称四极激电测深作为深部隐伏矿体预测的主要手段之一.激电剖面测深点距50~100m,局部加密到25m.对数据进行电反射系数、电阻率比值处理,可清晰判断出F40断裂带形态为上窄下宽,断裂带内的矿岩界线清晰.带内700点的下方深处,视极化率异常较高且与构造带吻合.经与区域同类型矿床对比,认为有全盲矿体.根据物探测深结果,结合区域成矿学、构造地质学理论,推测在700点下方400m深处有盲矿体,随后的验证钻孔在断裂带上部预测深度见到工业金矿体,厚度0.8m,Au品位3.24×10^(-6)为同类型地区及矿床预测提供了借鉴.
Reasonable geological interpretation is the premise and the key to blind orebody forecast by IP sounding. The prediction of Xiahaoping gold deposit is a good instance. The gold deposit has low resource reserves, 80 - 200 m fault throw, weak outcrop mineralization and significant differences of ore and rock properties. This paper chooses symmetric four-stimulated electrical sounding as a main prediction method. The point distance is 50 - 100 m and 25 m partly. By treating the power reflection coefficient and resistivity ratio, it concluded that there is blind orebody in the depth of 400 m below 700th point. The polarization is obviously ab- normal and close to the tectonic zone. It is considered that it is the reason why the mine leads to the abnormality by comparing with identical deposits in the region. And it is judged that there is blind orebody that exists in the depth of 400 m below 700 points according to the result of geophysical prospection. The gold orebody may be 0.8 m thick, and the grade is 3.24 × 10^(-6). The forecast has been confirmed by the drilling hole.