Application of Geochemi-cal Block Method in the Potential Prediction of Copper Resources in Eritrea
The Neoproterozoic East African orogeny formed a large area of exposed metavolcanic sedimenta-ry rock series and corresponding granitic magmatic rocks in the Arab-Nubian Shield,Eritrea,in which the copper resource is very rich.In this paper,1:1000000 stream sediment geochemical data in Eritrea was select-ed as the research object.Based on the theory of geochemical block method,we synthetically evaluated the Cu resource potential of Eritrea.The result of geochemical data shows that the value of geochemical anomaly threshold is 28×10-6.Seven geochemical blocks and five regional anomalies were delineated.According to the reserves of known deposits in different metallogenic belts,the mineral coefficient of Cu in each areawas cal-culated.The total copper tonnage and mineral resources in each area were calculated based on the exploration depth of the 1km.Thus,we inferred that the total copper tonnage in the 7 geochemical blocks and 5 regional geochemical anomalies of Eritrea(given a 1 km thickness of every rock mass)is 9.3076 million tons.Among them,geochemical blocks 5 and 6 should be used as the focus of the next step,and the exploration potential in geochemical blocks 1,2,3,4 and 7 should also be noted.