塞拉利昂某铁矿矿区地质特征及成因分析

Geological characteristics and genesis analysis of an iron mine in Sierra Leone

塞拉利昂地处非洲地盾西侧,其地质演化过程分为早期、中期、晚期三个阶段。早期与晚期以内生矿成矿为主,中期以外生成矿为主。矿区铁矿体主要赋存在马兰帕群洛托科隆组(Lmr)。主要岩性为磁铁石英岩、赤铁石英岩。含铁石英岩经风化淋滤,原地堆积,与泥质等物质形成"铁帽"及铁质胶结物。

Sierra Leone is located on the west side of the African shield,and its geological evolution process can be divided into three stages:early stage,middle stage and late stage.In the early and late stage,endogenetic ore-forming is dominant,and in the middle stage,exogenetic ore-forming is dominant.The ore bodies in the mine area are mainly distributed in the luotuocologne formation (LMR) of malanpa group.The main lithology is magnetite quartzite and hematite quartzite.After weathering and leaching,the iron bearing quartzite accumulates in situ and forms "iron cap" and iron cement with argillaceous materials.