广西扶绥铝土矿区的地质特征与成矿分析

Geological Characteristics and Metallogenic Analysis of Bauxite Deposit in Fusui County,Guangxi Province

扶绥铝土矿区位于广西铝土矿成矿带南带的核心区,存在大量火山灰,为更深入地剖析火山灰及其对成矿作用的意义,通过野外地质调查、室内显微镜鉴定及X射线衍射分析法进行研究。结果表明,沉积型铝土矿分为块状、碎屑状和致密状3种类型,堆积铝土矿为沉积铝土矿地表风化、堆积产物,继承了前者的矿石矿物、结构构造特征。铝土矿石中火山灰种类可分为岩屑、晶屑、玻屑和火山尘4种,为玄武岩、安山岩岩屑,长石、石英等基性-中性-酸性矿物。火山灰铝土矿化强烈,常生成水铝石、高岭石、赤铁矿等微细矿物,矿石中总含量大于50%,为铝土矿的重要物质来源。

Fusui bauxite mining area is located in the core area of the southern bauxite metallogenic belt in Guangxi,and there is a large amount of volcanic ash.In order to further analyze the volcanic ash and its significance to mineralization,field geological survey,laboratory microscopic identification and X-ray diffraction analysis were used to study the volcanic ash.The results show that sedimentary bauxite can be di⁃vided into three types:massive,clastic and dense.The accumulated bauxite is the product of weathering and accumulation on the surface of sedimentary bauxite,which inherits the ore mineral and structural character⁃istics of the former.The types of volcanic ash in bauxite ores can be divided into 4 kinds of rock debris,crys⁃tal debris,glass debris and volcanic dust,basalt,andesite debris,feldspar,quartz and other basic-medi⁃um-acid minerals.Volcanic ash bauxite is strongly mineralized,which often produces hydrobauxite,kaolin⁃ite,hematite and other fine minerals,the total content of ore is more than 50%,which is an important mate⁃rial source of bauxite.