摘要
非洲是全球铝土矿资源最丰富的大洲,以产有多个世界级铝土矿矿床而著称。为分析该地区铝土矿的地质特征、成矿规律和找矿前景,本文在总结非洲铝土矿资源禀赋特征的基础上,探讨了该地区铝土矿资源的区域成矿地质背景、矿床类型、成矿条件、成矿特征、时空分布规律和成矿演化过程,划分了成矿区带。研究表明:①非洲铝土矿资源主要集中分布在西非地区,具有储量巨大、品位高、埋藏浅、易开采等特点;②矿床类型为红土型,是在成矿构造环境、成矿母岩、古气候、古地形地貌等多种成矿条件耦合下,铝硅酸盐岩及富铝变质岩发生深度红土化作用的产物;③成矿母岩以中新生代基性侵入岩、火山岩及古元古代变质岩、古生代变质岩为主;④赋铝土矿红土风化壳具有垂直分带性;⑤成矿构造单元以西非克拉通为主;⑥主要成矿时代为晚白垩世-新生代。根据铝土矿的成矿构造环境、成矿特征和时空分布规律,将非洲铝土矿划分为西非铝土矿成矿省和东南非铝土矿成矿省2个成矿省及6个一级成矿带,这些成矿省、成矿带是非洲重要的铝土矿矿产地和找矿远景区,找矿潜力巨大。
Africa is a big continent hosting the most abundant bauxite resources on the Earth,well known for many world-class bauxite deposits.This paper analyzes the geological characteristics,metallogenic regularity,and prospecting potential of bauxite resources in Africa.We summarize endowment characteristics of bauxite resources,examine the regional ore-forming background,deposits types,ore-forming conditions,spatial and temporal distribution and metallogenic evolution process of bauxite resources,and divide the metallogenic belts in this continent.Research shows that①the bauxite resources are mainly distributed in West Africa,characterized by giant reserves,high grade and shallow burial depth.②The deposit type is of lateritic,which is the result of the strong laterization of aluminosilicate and rich alumina metamorphic rock under the multi-factor coupling of ore-forming tectonic setting,mineralization host rock,paleoclimate condition and paleotopography.③The Meso-Cenozoic basic intrusive rock and volcanic rock,Paleoproterozoic metamorphic rocks and Paleozoic metamorphic rocks are the main mineralization mother rocks.④The laterite weathering crust profile with bauxite ore bodies is featured by obvious vertical zoning.⑤The West Africa Craton is the dominant ore-forming tectonic unit.⑥The main metallogenic epoch of bauxite deposits spans from Late Cretaceous to Cenozoic.According to the ore-forming tectonic setting,ore-forming characteristics and the spatial and temporal distribution,two important metallogenic provinces and six metallogenic belts are divided of bauxite resources in Africa,which are West Africa and Southeast Africa provinces,Man-Lèo Shield,Beauvais basin Kenieba tectonic window,Fongo Tongo in the Cameroun-Pala area and in Chad,Tanzanian Craton and Mozambique orogenic bauxite metallogenic belts,respectively.These metallogenic provinces and belts are the most important mineral resources and metallogenic prospects with great ore-search potential in Africa.
作者
陈喜峰
施俊法
陈秀法
王杨刚
李玉龙
高爱红
CHEN Xifeng;SHI Junfa;CHEN Xiufa;WANG Yanggang;LI Yulong;GAO Aihong(Development Research Center of China Geological Survey,Beijing 100037)
出处
《地质与勘探》
CAS
CSCD
北大核心
2021年第6期1203-1215,共13页
Geology and Exploration
基金
中国地质调查局地质调查项目(编号:DD20211404)资助。
关键词
地质特征
成矿规律
找矿前景
铝土矿
非洲
geological characteristics
metallogenic regularity
prospecting potential
bauxite deposits
Africa
