激电中梯及音频大地电磁测深(EH4)在镇雄银厂湾铅锌矿区勘查中的应用

Applocationof IPelectric elevator and audio magnetoteuric(EH4)in the exploration of Zhenxiong Yinchangwan lead-zn mining area

镇雄银厂湾铅锌矿属于沉积-构造-热液叠加改造型铅锌矿床.运用激电中梯及音频大地电磁测深(EH4)方法,对银厂湾铅锌矿区外围及深部进行了2条物探剖面测量分析;根据0线剖面已知矿体(KT1)、断裂和地层(梁山组、阳新组、宝塔组)等电性(视电阻率、视极化率)特征,分析和解释5线物探剖面电性特征;认为两者(激电中梯、EH4)电性特征形态一致,说明了两者数据真实有效,进一步反映了矿区深部的电性分布特征;主判识了断裂3条(F_(1)~F_(3)),其中断裂(F_(1))为主断裂,为成矿提供能源(物质)通道;断裂(F_(2)、F_(3))为次级断裂,为矿化提供有利场所;圈定了2处找矿有利部位(TKT1、TKT2),进一步推断在断裂(F_(1))深部可能存在规模较大矿体.激电中梯和音频大地电磁测深(EH4)相结合方法对银厂湾铅锌矿区外围及深部指导找矿工作是很有效的地球物理方法.

The Yinchangwan lead-zinc deposit in Zhenxiong belongs to the sedimentary-tectonic-hydrother-mal superimposed transformation type of lead-zinc deposit.Two geophysical profiles were measured and analyzed in the periphery and deep part of Yinchangwan lead-zinc mining area by means of IP medium ladder and audiofrequency magnetotelluric sounding(EH4).Based on the o lone profile,the orebody,foult and stratum(Liangshan Formation,Yangxin Formation,Baota Formation)and other electrical properties(apparent resistivity,apparent polarizability)are known,the electrical properties of the 5-line geophysical profile are analyzed and explained;The shapes are consistent,indicating that the two data are true and effective,and further reflect the electrical distribution characteristics in the deep part of the mining area;3 faults(F1-F3)are identified,of which the fault(F1)is the main fault,providing energy for metallogenic(material)channel;faults(F2,F3)are secondary faults,providing favorable sites for mineralization;2 favorable sites for ore prospecting(TKT1,TKT2)have been delineated,and it is further inferred that there may be large-scale deposits deep in the fault(F1).body.The combined method of IP medium ladder and audio magnetotelluric sounding(EH4)is a very effective geophysical method to guide the prospecting work in the periphery and deep of Yinchangwan lead-zinc mining area.