桂中地区上二叠统合山组关键金属分布富集特征  

Distribution and enrichment characteristics of critical metals in the upper Permian Heshan formation in the central Guangxi

作　　者：覃顺桥 雷美荣[1] 凌坤跃 温汉捷 QIN Shun-qiao;LEI Mei-rong;LING Kun-yue;WEN Han-jie(The No.7 Geological Team of Guangxi Zhuang Autonomous Region,Liuzhou,Guangxi 545100,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;College of Earth Science and Resources,Chang’an University,Xi’an 710054,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]广西壮族自治区第七地质队,广西柳州545100 [2]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵阳550081 [3]长安大学地球科学与资源学院,西安710054 [4]中国科学院大学地球与行星科学学院,北京100049

出　　处：《矿物岩石地球化学通报》2023年第1期157-166,共10页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(92062107,92162214);云南省重点研发计划项目(202103AQ100003);中国科学院地质与地球物理研究所重点部署项目(IGGCAS-201902);中国科学院重点部署项目(ZDRW-ZS-2020-4-1);贵州省科技计划项目(黔科合基础[2019]1319,黔科合基础-ZK[2021]重点046)。

摘　　要：碳酸盐黏土型锂资源是近年来我国西南地区发现的一类新型锂资源。目前已发现的富锂黏土岩均与铝土矿产自同一层位。为了解桂中地区铝土矿赋矿地层——上二叠统合山组的关键金属资源状况,对其开展了矿物学和地球化学分析研究。结果发现,合山组中Li、Ga、Nb等关键金属元素均有不同程度的富集。Li、Ga、Nb分别富集在硬水铝石、黏土矿物或硬水铝石和锐钛矿中。其中,Li在氧化条件下形成的铁质铝土岩中最富集,在陆相-过渡相沉积环境中,具有较低盐度、弱碱性水体条件的滨海盆地是Li富集的理想场所。Ga和Nb主要富集在氧化、亚氧化条件下形成的铁质铝土岩、部分页岩和部分黏土岩/泥岩中,陆相和过渡相沉积环境最有利于Ga和Nb的富集。The Carbonate-hosted clay-type lithium resource is a new type of lithium resource discovered in Southwest China in recent years. At present, the discovered lithium-rich claystones are all in the same horizon as the bauxite ores in China. Hence, we have carried out a survey of critical metal resource in the sedimentary strata of the bauxite-hosted Upper Permian Heshan Formation in the central Guangxi, and have found that some critical metals such as Li, Ga, and Nb are enriched in different degrees of enrichment. Mineralogical and geochemical analytical results show that Li, Ga, and Nb are enriched in diaspore, clay minerals/diaspore, and anatase, respectively. Li is mostly enriched in the iron-rich bauxite formed under the oxidative condition. The terrestrial-transitional depositional environment was often formed in the coastal basin with low salinity and weakly alkaline water conditions, which is an ideal place for the Li enrichment. In addition, Ga and Nb are mainly enriched in iron-rich bauxite, and parts of shale and clay/mudstone which were formed under oxidative and sub-oxidative conditions. Terrestrial and transitional depositional environments are mostly favorable for the enrichment of Ga and Nb in those sediments.

关 键 词：关键金属 碳酸盐黏土型锂资源 合山组 资源调查 

分 类 号：P611.2[天文地球—矿床学]