厄立特里亚GASH金矿集区地球化学特征及信息提取

Geochemical Characteristics and Information Extraction in GASH Ore Concentration Area,Eritrea

GASH金矿集区位于厄立特里亚西部的碧沙Au多金属成矿带,具有良好的区域成矿背景。区内1∶10万水系沉积物测量数据的地球化学特征表明,Au、Hg、As、W、Bi等元素呈强分异的分布特征,Au、As、Sb、W具有强富集的分布特征,显示优异的Au找矿前景。通过元素相关性分析,筛选出能够有效指导Au矿勘查的F5因子(Au-Hg元素组合)、指示区域断裂构造分布的F2因子(Ag-Bi-Mo-W元素组合)及F3因子(As-Sb-Pb元素组合),指示基性–超基性地质体分布的F1、F4特征因子。对F5因子得分开展异常信息提取,并结合矿产地质特征,圈定出可开展进一步原生岩金矿勘查工作的异常区8处,基于指示成矿热液活动的F2、F3、F5特征因子推断出NE、N–NE向的规模较大的断裂12条,为研究区的找矿预测及勘查工作部署提供了有利的地球化学依据。

GASH Au ore concentration area belongs to Bisha gold metallogenic belt in West Eritrea,with a good regional metallogenic setting.The geochemistry of stream sediment mapping at scale of 1∶100,000 indicate:Au,Hg,As,W,Bi are characteristic of strong-differentiated distribution,Au,As,Sb,W are characteristic of strong-rich distribution,showing a good prospecting for Au exploration.Through the correlation analysis,F5 factor(Au-Hg association)is confined to guide the Au exploration,F2 factor(Ag-Bi-Mo-W association)and F3 factor(As-Sb-Pb association)which are confined to guide the distribution of fault structures,F1 and F4 factor are confined to guide the distribution of basic and ultrabasic geological unit.with the anomaly information ex-tract from F5 factor combined with the geological characteristic,8 anomaly area with good Au metallogenic prospecting were determined,base on the characteristic of F2,F3,F5 factors,which are useful in indicating the metallogenic hydrothermal activity,12 regional fault with NE,N-NE attitude were deduced.All the information extracted are useful geochemical evidence to the following gold exploration and the work deployment.