塞拉利昂马声谷矿区地质特征及成矿规律分析  

Analysis of Geological Characteristics and Metallogenic Law of Mashenggu mining area in Sierra Leone

作　　者：申红涛 李新 贾志泉[2] SHEN Hong-tao;LI Xin;JIA Zhi-quan(403 Geological Team of Sichuan Geological and Mineral Exploration and Development Bureau,Mount Emei 614200,China;108 Geological Team of Sichuan Geological and Mineral Exploration and Development Bureau,Chongzhou 611230,China)

机构地区：[1]四川省地质矿产勘查开发局四〇三地质队,四川峨眉山614200 [2]四川省地质矿产勘查开发局一〇八地质队,四川崇州611230

出　　处：《世界有色金属》2019年第13期285-285,287,共2页World Nonferrous Metals

摘　　要：矿区位于塞拉利昂非洲地盾西侧,其地质演化过程分为三个阶段:①早期岩浆活动强烈,差异性升降明显,各类构造运动发育;②中期趋于稳定,表现为整体升降,局部凹陷区域沉积;③晚期整体上隆,脱离海侵,趋于稳定,边缘与断裂带伴有较强岩浆活动。早期与晚期以内生矿成矿为主,中期以外生成矿为主。含矿建造属塞拉利昂马兰帕~库库纳含铁石英建造带,铁矿体赋存于马兰帕群洛托科隆组(Lmr),矿床成因类型为前寒武系地盾区的沉积~变质型(BIF)铁矿。铁矿体的主要成矿条件和控制因素为太古代上地壳马兰帕群洛托科隆组(Lmr)含矿层位,区域变质作用对铁矿加富,区域变作用过程中苏布亚~隆萨背斜褶皱构造形变对矿体形态影响比较大,造成区内矿体在厚度、品位系数上有较大变化。Located on the west side of Sierra Leone's African Shield,the geological evolution process of the mining area can be divided into three stages:①strong magmatic activity in the early stage,obvious differential uplift and fall,and the development of various tectonic movements;②stable in the middle stage,characterized by overall uplift and subsidence in the local depression area;③overall uplift in the late stage,breaking away from transgression,and tending to develop.The margin and fault zone are accompanied by strong magmatic activity.Endogenous mineralization is dominant in the early and late stages,and mineralization is dominant outside the middle stage.The genetic type of the deposit is deposit-metamorphic iron ore in the Precambrian shield area.The main ore-forming conditions and controlling factors of the iron ore bodies are the ore-bearing horizon of the Lotokolon Formation(Lmr)of the Malanpa Group in the Archean upper crust.Regional metamorphism enriches the iron ore.During the process of regional metamorphism,the structural deformation of the Subula-Longsa anticline fold has a greater impact on the shape of the ore bodies,resulting in a greater thickness and grade coefficient of the ore bodies in the area.Great changes.

关 键 词：塞拉利昂 非洲地盾 前寒武系基底杂岩 铁矿 马兰帕群洛托科隆组 

分 类 号：P618.2[天文地球—矿床学]