赞比亚卢安夏矿田铜矿床地物化综合找矿模型构建与应用

Construction and application of geophysical and geochemical comprehensive prospecting model for copper deposit in Luanshya ore field,Zambia

赞比亚卢安夏矿田铜矿床受区域构造制约,矿床分布于盆地内次级向斜构造中,矿体定位受罗恩群基特韦亚群RL6地层控制,铜矿化主要富集在不纯白云岩和泥质岩中,矿体呈层状与围岩整合接触,形态随褶皱构造的形态变化而变化。浅部到中深部矿体具有“中低阻和中高极化”特征,在“中低阻和中高极化”异常与中深部稳定电性分层上的低阻异常吻合时可以对矿化体进行定位预测。Cu、Ag、Bi元素异常在近地表氧化矿呈“驼峰”高值异常,在深部硫化矿上方呈“偏锋”弱异常。组合异常衬度高,异常同步清晰,可有效指示与矿体赋存范围。据此建立的地物化找矿模型应用效果良好,在赞比亚铜带省内沉积-变质型铜矿床具有良好的应用价值。

The copper deposit of Luanshya ore field in Zambia is restricted by regional structure. The deposit is distributed in the secondary syncline structure in the basin. The location of the ore body is controlled by the RL6 stratum of the Ron group Kitwea group. The copper mineralization is mainly enriched in impure dolomite and argil⁃ laceous rock. The ore body is in an integrated contact with the surrounding rock, and the shape changes with the shape of the fold structure.The shallow to medium-deep ore bodies have the characteristics of medium-low resistance and medium-high polarization.When the medium-low resistance and medium-high polarization´anomalies coincide with the low resistance anomalies on the stable electrical stratification in the middle and deep layers,the mineralization body can be located and predicted.The anomalies of Cu,Ag and Bi elements are´hump high value anomalies in the near-surface oxidized ore,and partial´weak anomalies above the deep sulfide ore.The anomaly contrast of combination is high,and the anomaly synchronization is clear,which can effectively indicate the occurrence range of ore body.The geophysical-geochemical prospecting model established on this basis has good application effect and has good application value in sedimentary-metamorphic copper deposits in Zambia´s copper belt province.