内蒙古嘎仙镍钴矿区物探找矿方法技术组合及应用

Combination and application of geophysical prospecting methods and techniques in Gaxian nickel and cobalt mine,Inner Mongolia

嘎仙镍钴矿地处西伯利亚地台与中朝准地台过渡地带,位于内蒙—大兴安岭褶皱系大兴安岭优地槽褶皱带,属岩浆熔离—热液改造型硫化物镍矿床。该矿床类型特征与常见的铜镍硫化物矿床不同,镍品位低、贫铜,镍钴矿(化)体赋存辉石橄榄岩中。金属矿物主要由黄铁矿、镍黄铁矿和磁铁矿等组成,其中镍黄铁矿与黄铁矿紧密共生,成不规则颗粒状镶嵌于黄铁矿中;而磁铁矿一般形成较晚,多见于镍黄铁矿中,呈网脉状产出。磁黄铁矿、镍黄铁矿呈浸染状、细脉状、细脉浸染状,局部斑块状、脉状,矿产于辉石橄榄岩中。通过对该区开展的地球物理工作,不仅对镍矿(化)体的空间分布特征及矿化富集规律有了很好的认识,而且总结出了该区找矿的最佳技术方法组合,即大功率单极—偶极测深装置激发极化法与高精度磁法的结合。

The Gaxian Ni - Co deposit locats between Siberian platform and Sino - Korea paraplatform. This deposit is a mag- matic liquation - hydrothermal rework sulfide deposit. It is different from other common Cu - Ni sulfide deposit in its low grade of Cu and Ni , Ni - Co ore body ouccurs in pyroxene periodate. Ore minerals is consisted of pyrite, pentlandite and magnetite etc. The inter- growth of pentlandite and pyrite forms disorder granulation. Commonlly magnetite forms later than the others and always found in pent- landite as stockworks. Pyrrhotite and pentlandite show in dissemination, veinlet, veinlet- dissemination and partially plaque or vein structues. Geophysical exploration in this area not only undercovered spatial distribution features of Ni orebodies and regularity of min- eralization and enrichment, but also found the best technique combination for prospecting similar deposits in this area, which is consis- ted of high - power IP （ pole - dipple array） sounding and high - precision magnetic survey.