西非铁矿资源特征及成矿规律

The iron ore resource feature and metallogenic regularity in western Africa

近年来,伴随着西非铁矿找矿工作的不断突破,其资源潜力再次得到国际矿业巨头的关注。中国是全球最大的铁矿资源消费国,研究西非铁矿的资源特征及成矿规律,对于深入了解西非铁矿资源潜力及未来与中国的资源合作部署具有重要意义。系统总结西非铁矿成矿地质背景及资源禀赋特征,梳理西非10个主要产铁国的91处铁矿山信息,将西非铁矿成因类型分为BIF(条带状铁建造)型、矽卡岩型、岩浆型、红土型、鲕状矿石型。根据铁矿产出的地质背景和空间位置,划分了20个Ⅳ级成矿区带。在此基础之上,总结了西非铁矿的时空分布规律:西非铁矿空间上分布广泛,但具有明显的丛聚性分布特征,且不同成因类型的铁矿分布也有所不同。BIF型铁矿主要产于古老地盾区;红土型铁矿多伴生BIF存在,与热带气候密切相关;矽卡岩型铁矿主要分布于泛非活动带与沉积盆地的边界位置;岩浆型铁矿主要赋存在分异性良好、以辉长岩为主的基性岩体中;鲕状型铁矿主要产于中—新生代盆地中。

In recent years,with the continuous breakthrough in the iron ore prospecting work of western Africa,its resource potential has once again attracted the attention of international mining giants.China is the world's largest consumer of iron ore resources.Thus,the resource characteristics and mineralization regularity of western Africa iron ore are summarized,which could help understand the iron ore resources potential of western Africa and provide basis for the future collaborative deployment of resources.This paper systematically summarizes the iron ore metallogenic geological background and resource endowment characteristics in western Africa.Based on the information of 91 iron ore deposits in 10 major iron-producing countries of western Africa,we classified the genetic types of iron ore in western Africa into BIF(Banded Iron Formations)type,skarn type,magmatic type,laterite type,oolitic ore type.According to the tectonic units of iron ore,20 metallogenic zones have been divided in western Africa.On this basis,we summarized the spatial distribution regularity and temporal distribution characteristics of iron ore in western Africa.The iron ore deposits in western Africa are widely distributed in space,but they have obvious cluster distribution characteristics.The distribution of different genetic types of iron ore deposits are also different.The BIF type iron ore deposits are mainly produced in the ancient shield area.The laterite iron ore deposits are associated with BIF,which are closely related to tropical climate.The skarn type iron ore deposits are mainly distributed in the boundary of the Pan-African active belt and sedimentary basin.The magmatic type iron ore deposits mainly occur in the gabbro with good differentiation.The oolitic iron ore deposits are mainly developed in the Meso-Cenozoic basins.