相位激电法在牛家营银铅锌多金属矿的找矿勘查实践

Application of Phase Induced Polarization Method in the Prospecting and Exploration of Niujiaying Ag-Pb-Zn Polymetallic Deposit

牛家营铅锌多金属矿位于张家口市,地处坝上高原,地表均为第四系覆盖,工作程度较低。20世纪60年代初,该矿经地表地质工作,圈定出了NW—SE走向的两条矿化带,后经多次物探勘查,未发现致矿异常,已有的研究成果表明该区存在矿体的可能性较小。为寻求找矿突破,结合该区已有的地质勘探成果,在分析矿区地质特征的基础上,采用相位激电法进行找矿勘查。首先在矿区已知的矿化带上设计了相位激电测量试验剖面,分析该方法的适应性并选择合理的极距参数;然后完成了16条测线的相位激电测量工作,据此圈定了Ⅰ~#、Ⅱ~#主要异常带,经解译,认为两者均为矿致异常;最后在100~#线布设了相位激电测深剖面,对Ⅰ~#、Ⅱ~#异常特征进行了进一步分析,认为Ⅰ~#、Ⅱ~#异常源即为矿脉,与钻探验证(ZK-1、ZK-2钻孔)结果较吻合。在上述分析的基础上,进行了进一步的矿产勘查,查明该区银金属储量约5 t,铅锌金属综合储量在1.5万t以上,形成了牛家营小型银铅锌多金属矿床。采用相位激电法在牛家营铅锌多金属矿点进行的找矿勘探实践实现了区内找矿突破,可为该区进一步开展深部找矿工作提供参考。

Niujiaying Pb-Zn polymetallic deposit is located in Zhangjiakou city,the deposit is located in the Bashang plateau,its surface is covered by Quaternary stratum,the exploration degree of the mining area is low.In the early 1960＇s,two mineralization belts with the direction of NW—SE are delineated by conducting related geological work in the mining area,after that,geological prospecting work is conducted for many times in the area,but no mineralization anomaly is found.The existing geological prospecting results show that it is less likely to found the ore-bodies in the area.In order to seek for the prospecting breakthrough in the area,combing with the existing results of the area,based on analyzing the geological characteristics of the mining area,the phase induced polarization method is adopted to conduct prospecting work in the area.Firstly,a profile upper the known mineralization belt of the mining area is designed as the test profile of phase induced polarization method to analyze the adaptation of the method and choose reasonable pole pitch parameters; then,the phase induced polarization measurement work of 16 lines are conduced in the mining area,based on the measurement results,Ⅰ-#、Ⅱ-#main anomalies belts are delineated,the Ⅰ-#、Ⅱ-#anomalies interpretation results show that they are both mineralization anomalies; finally,the phase induced polarization sounding profile is set in location of 100-#line so as to further analyze the characteristics of Ⅰ-#、Ⅱ-#anomalies,the results indicated that anomalous source of Ⅰ-#、Ⅱ-#anomalies are both veins,which is basically consistent to the drilling results（ZK-1,ZK-2）.Based on the above analysis results,the further mineral prospecting work in the area is conducted,the results show that Ag metal reserves is 5 t and the comprehensive metal reserves of Pb and Zn is more than 1.5 × 104 t,therefore,the Niujiaying Ag-Pb-Zn polymetallic deposit is formed based on the resources of Ag,Pb,Zn.The above analysis results further show that the prospecting breakthrough is realized by conducting prospecting work by using phase induced polarization method,it can provide some reference for the deep prospecting and exploration work of similar areas.