靖西新圩沉积铝土矿含矿岩系与成矿环境研究  

Study on Ore-bearing Rock Series and Metallogenic Environment of Xinxu Sedimentary Bauxite in Jingxi

作　　者：韦访 李活松 张珩清 谭斌 覃良朝 WEI Fang;LI Huosong;ZHANG Hengqing;TAN Bing;QIN Liangchao(Guangxi Institute of Geological Survey,Nanning530023)

机构地区：[1]广西壮族自治区地质调查院,南宁530023

出　　处：《四川地质学报》2023年第3期410-417,共8页Acta Geologica Sichuan

基　　金：广西壮族自治区地质矿产局“桂西地区沉积型铝土矿控矿因素、成矿规律与找矿预测研究”(桂地矿综研[2021]85号);广西关键矿产资源深部勘查人才小高地(2019—2023年)(桂组通字[2019]85号)。

摘　　要：靖西新圩沉积铝土矿产出于早二叠世茅口灰岩之上的古风化壳之上,属典型沉积铝土矿床,含矿岩系具有“铁-铝-泥-灰”的特征,沉积环境具有从陆相到海相的转变。沉积铝土矿相对堆积铝土矿更富集稀土元素,围岩从纯灰岩-含泥灰岩-砂质页岩/粉砂岩REE总量依次增多。Eu、Ce特征与REE配分曲线显示沉积铝土矿与同期凝灰岩关系密切,表明成矿物源部分来自火山物质。沉积环境反应敏感的Be、Ga、Sr、Ba微量元素及比值分析表明铝土矿成矿环境为陆相,以原地残积为主,异地迁移沉积次之。Xinxu sedimentary bauxite deposit in Jingxi is a typical sedimentary bauxite deposit,which is produced on the ancient weathering crust of the Early Permian Maokou Limestone.The ore-bearing rock series shows the characteristics of"iron-aluminum-mud-ash",and the sedimentary environment has the transition from continental facies to Marine facies.The sedimentary bauxite is enriched in rare earth elements than the accumulation bauxite,and the content of REE in the surrounding rock increases successively from pure limestone to mud-limestone,to sandy shale/siltstone.The Eu,Ce characteristics and REE partition curves show that the sedimentary bauxite,which is closely related to the contemporaneous tuff,indicating that the mineral source is partly from volcanic material.The analysis of sensitive to sedimentary environmenttrace elements(such as Be,Ga,Sr and Ba)and their ratios shows that the ore-forming environment of bauxite is continental facies,mainly in autochthonous residual deposits,followed by allochthonous migratory deposits.

关 键 词：沉积铝土矿 微量元素 沉积环境 地球化学 

分 类 号：P588.22[天文地球—岩石学] P595[天文地球—地质学]