新疆昭苏阿尔恰勒他乌铅锌矿床地球物理特征与深部找矿预测

摘要

阿尔恰勒他乌铅锌矿床是一个矿床分带清晰、控矿机理明显及矿化蚀变强烈的多金属矿床,铅锌矿体产于灰岩地层,产状与围岩基本一致,已知矿体上的实验表明矿体具有低阻高极化的特点.采用激电中梯扫面在矿区圈出了6个激电异常区,并在激电异常区内开展音频大地电磁测深工作,查明了激电异常区地下深部构造的电性情况,结合矿区矿体特征及成矿模式,建立了矿区地球物理音频大地电磁测深电性找矿模型,指出倾斜或层状的中低阻电性异常最有可能是含矿构造带存在的地球物理标志.综合物探激电扫面、音频大地电磁测深、地质等信息,圈出2个找矿靶区,经钻孔在Ⅱ号靶区19号线验证,在孔深331~349m见到厚度约18m的矿体.激电法与音频大地电磁测深的方法技术组合可以在该类型矿床深部找矿中推广使用.%Aerqialetawu Pb-Zn deposit is a polymetallic deposit which is characterized byclear zoning of ore de-posits,distinct ore-controlling mechanism andintensive mineralization and alteration.The Pb-Zn orebodies occur in limestone formation,with basically the same occurrence as that of wall rocks.Experiments on the known orebodies showed that the orebodies had the characteristics of low resistance and high polarization.6 IP anomaly regions were blocked out by applying IP intermediate gradient surface scanning.Then audiofre-quency magnetotelluric sounding works were carried out in these IP anomaly regions to verify the electrical properties of deep structures inside the regions.Combined with orebodies'features and metallogenic model, the authors set up a prospecting model by using electrical properties which were acquired from audio frequen-cy magnetotelluric sounding works in the mining area,and they pointed out the anomaly of low-medium elec-trical property anomalies which occurred in the inclined and bedded form were the most possible geophysical marks of ore-bearing tectonic belts.Based on IP surface scanning,audio frequency magnetotelluric sounding and geological information,2 target areas of prospecting were blocked out.No.19 line in No.II target area was verified by drilling,and a 18-meter-thick orebody was discovered at depth of 331-349m in the drilling borehole.A technical combination of IP method and audio frequency magnetotelluric sounding could be use-ful in the deep prospecting of the same type of deposits.