广西上林万福矿区晚二叠世合山组煤系锂地球化学特征及物源研究  

Geochemical characteristics and provenance of lithium in the Late Permian Heshan Formation coal-bearing series from the Wanfu mining area,Shanglin,Guangxi Province

作　　者：张德高 徐小涛 孙杰 张福强 李宝庆[4] 张莉 庄新国[4] 严晓云 ZHANG Degao;XU Xiaotao;SUN Jie;ZHANG Fuqiang;LI Baoqing;ZHANG Li;ZHUANG Xinguo;YAN Xiaoyun(General Prospecting Institute China National Administration of Coal Geology,Beijing 100039,China;Key Laboratory of Transparent Mine Geology and Digital Twin Technology,National Mine Safety Administration,Beijing 100039,China;Guangxi Bureau of Coal Geological Exploration,China National Administration of Coal Geology,Nanning 530299,China;Faculty of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中国煤炭地质总局勘查研究总院,北京100039 [2]矿山透明地质与数字孪生技术国家矿山安监局重点实验室,北京100039 [3]中国煤炭地质总局广西煤炭地质局,广西南宁530299 [4]中国地质大学(武汉)资源学院,湖北武汉430074

出　　处：《煤炭学报》2024年第9期3884-3895,共12页Journal of China Coal Society

基　　金：中国煤炭地质总局科技创新资助项目(ZMKJ-2023-JBGS03-01);国家自然科学基金资助项目(42141012,42102211)。

摘　　要：广西上林晚二叠世合山组含煤岩系中广泛存在锂元素富集的现象,具有潜在的经济价值和研究意义。本次研究以广西上林万福矿区晚二叠世合山组煤系锂矿化层为研究对象,在对34件样品常量元素和微量元素测试,并对1件样品锆石U–Pb测年和锆石微量元素测定的基础上,综合分析了区内合山组煤系锂矿化层的空间分布、元素地球化学特征和物质来源。研究发现,合山组煤系自下而上有Ⅰ、Ⅱ、Ⅲ和Ⅳ四套锂矿化层,锂质量分数由高到低依次为层Ⅰ、层Ⅲ、层Ⅱ和层Ⅳ。与世界黏土岩均值相比,层Ⅰ中Li元素属于高度富集,层Ⅱ、层Ⅲ中Li元素属于富集,而层Ⅳ中Li元素属于轻微富集;Al_(2)O_(3)–TiO_(2)、La/Sc–Th/Co和V–Ni–Th×10物源区岩性判别图解显示,层Ⅰ、层Ⅲ和层Ⅳ的大部分样品点落在酸性岩浆岩区附近,层Ⅰ中少数样品点落在中性岩浆岩区域,由此推断,万福矿区合山组煤系锂矿化层主要来自酸性和中性岩浆岩。通过对锆石U–Pb定年、锆石微量元素Th/Nb−Hf/Th和Th/U–Nb/Hf构造判别图、稀土元素分析以及Al_(2)O_(3)–TiO_(2)、La/Sc–Th/Co、V–Ni–Th×10和Nb/Y–Zr/TiO_(2)四个物源判别图的综合研究得出,万福矿区合山组煤系锂矿化层主要来自峨眉山大火成岩省和古特提斯二叠纪岩浆弧相关的中酸性岩浆岩。Lithium element enrichment is widely observed in the coal-bearing series of the Late Permian Heshan Formation in Shanglin,Guangxi,which has potential economic value and research significance.In this study,a multi-proxy study was conducted for evaluating major elements,trace elements,zircon U–Pb dating,and zircon trace elements from the lithium mineralization layers to characterize the spatial distribution,elemental geochemical characteristics,and provenance of lithium mineralization layers of the Late Permian Heshan Formation coal-bearing series in the Wanfu mining area,Shanglin,Guangxi.Thirty four samples were selected from lithium mineralization layers in order to determine major elements and trace elements.Moreover,the zircon U–Pb dating and zircon trace elements of one sample was investigated.The study reveals that four sets of lithium mineralization layers,namelyⅠ,Ⅱ,Ⅲ,and Ⅳ,are developed from bottom to top in the Heshan Formation coal-bearing series from the Wanfu mining area,Shanglin,Guangxi.According to the order of lithium content from high to low,it is divided into lithium mineralization layersⅠ,Ⅲ,Ⅱ and Ⅳ.Compared with average values for world claystone,the lithium mineralization layerⅠare highly enriched in Li,the Ⅱ and Ⅲ is enriched in Li,and the Ⅳis slightly enriched in Li.The analysis of Al_(2)O_(3)–TiO_(2),La/Sc-Th/Co and V–Ni–Th×10 diagrams indicate that most of the samples of lithium mineralization layer Ⅰ,Ⅲ and Ⅳfall close to the acidic volcanic rocks field,while a few samples of lithium mineralization layer I fall near the intermediate volcanic rocks field.Therefore,it is inferred that the lithium mineralization layers of the Heshan Formation in Shanglin,Guangxi are dominated by sediments derived from the acidic and intermediate volcanic rocks.The Zircon U–Pb dating,Th/Nb-Hf/Th and Th/U–Nb/Hf tectonic setting discrimination diagrams of zircon trace elements,rare earth elements analysis,and Al_(2)O_(3)–TiO_(2),La/Sc−Th/Co,V–Ni–Th×10 and Nb/Y�

关 键 词：煤系锂 地球化学特征 合山组 万福矿区 锆石U–Pb定年 物源分析 

分 类 号：P618.71[天文地球—矿床学]