非洲加纳上东部省ZA区金矿化探异常及找矿新突破分析

Geochemical anomaly and new breakthrough in prospecting gold deposit in ZA district,Upper East province of Ghana,Africa

加纳北部上东部省ZA区,位于Bolo-Nangodi金成矿带的东北部。以往在南部阿散蒂等5个金矿带中发现了数个大型金矿床,而在北部的2个金矿带中只发现了一处大型金矿床。经勘查证实,研究区内大型工业开发价值金矿的发现,是北部成矿带中的找矿新突破。通过110000土壤地球化学测量工作,分析了非洲加纳上东部省ZA区内金矿床化探异常特征,提出了找矿方向。对元素相关性进行了分析,确定了成矿元素共生组合,进而圈定了成矿有利地段,共圈定金综合异常19个,其中甲类异常3个,乙类异常2个。经后期地表槽探和深部钻探工程验证,认为甲类金综合异常与金矿体存在着明显的对应关系,表明该区110000土壤化学异常能有效地指导找矿工作。通过与工作区已验证的异常对比,初步预测整个探矿权范围内具备100 t以上金矿的成矿潜力。

ZA district,Upper East province,northern Ghana,located in the northeast of the Bolo-Nangodi gold metallogenic belt.In the past,several large gold deposits have been found in five gold belts such as Ashanti in the south,while only one large gold deposit has been found in two gold belts in the north.The discovery of large industrial gold deposit in the study area is a new breakthrough in prospecting in the northern metallogenic belt.Based on 110000 soil geochemical survey,this paper analyzed the geochemical anomaly characteristics of gold deposit in ZA area of Upper East Ghana province,Africa,and put forward the prospecting direction.The correlation of elements was analyzed,the symbiotic association of ore-forming elements was determined,and then the favorable ore-forming areas were delineated.A total of 19 comprehensive anomalies were enclosed,including 3 type A anomalies and 2 type B anomalies.Through the verification of surface trough exploration and deep drilling,it is believed that there is an obvious correspondence between the comprehensive anomaly of type A gold and the gold orebody,indicating that 1:10000 soil chemical anomaly in this area can effectively guide the prospecting work.By comparing with the verified anomalies in the working area,it is preliminatively predicted that there is more than 100 tons of gold mineralization potential in the scope of whole exploration rights.