东北非与中国胶东造山型金矿对比及对非洲找矿勘查的启示

东北非是一个快速兴起的世界级金矿省，发育大量造山型金矿床。选择东北非努比亚地盾代表性造山型矿床进行总结梳理，认为区内金矿成矿可能受控于努比亚地盾地块拼帖后挤压/压扭向张扭剪切转换的过程，绿片岩相-角闪岩相变质基性火山岩是主要赋矿围岩，剪切带(断层)为主要控矿构造。通过对比，发现努比亚地盾矿集区与胶东矿集区类似，在大规模金成矿前均经历了洋壳俯冲过程，除赋矿围岩和成矿时代区别明显外，在控矿构造、矿化类型、矿物组合、成矿流体等方面较相似。结合控矿因素与找矿标志对比，针对努比亚地盾造山型金矿的找矿勘查提出具体建议：通过遥感和地质图修编圈定找矿远景区；利用地球化学测量和地质图草测等圈定找矿靶区；利用蚀变填图、反循环钻探，结合电磁测量，追踪隐伏矿体；通过矿床理论研究和矿田构造分析，支撑矿床(点)深部找矿。

A comparison between orogenic gold deposits in Northeast Africa and Jiaodong,China and its implications for exploration in Africa

The Nubian shield in the Northeast Africa is an emerging world-class gold province with numerous orogenic gold deposits.Based on the investigation of some representative orogenic gold deposits, the geological features related to the orogenic gold deposits in the Nubian shield were summarized.It is suggested that gold mineralization in this area might be formed during the transition from compression to tensional shear after block accretion of the Nubian shield, the greenschist-amphibolite facies metamorphic rocks are main host rock, and the shear zones (faults) are main ore-controlling structures.The orogenic gold deposits in the Nubian shield and Jiapdong in China underwent oceanic crust subduction before large-scale mineralization.Both are similar in ore-controlling structures, mineralization type, mineral assemblages and ore-forming fluids, except for the obvious differences of host rocks and metallogenic ages.Combined with the comparison of ore-controlling factors and prospecting indicators, some detailed suggestions for the orogenic gold deposits exploration in Nubia Shield are proposed as follows: remote sensing and geological mapping to outline potential area; geochemical and geological brief survey to target prospecting area; alteration mapping, reverse circulation drilling and electromagnetic survey to track hidden ore bodies; theoretical study and structural analysis to promote deep ore-prospecting.