中国西南滇黔桂关键资源远景新区锂地球化学时空分布特征及找矿预测

锂因其在新能源领域的应用广泛性和不可替代性而备受关注。以往锂矿勘查主要集中于盐湖型和硬岩型锂矿，针对沉积型锂矿开展工作较少。本文聚焦于中国西南滇黔桂地区，以岩石和水系沉积物中锂的时空分布特征为基础，分析区域内沉积型锂矿成矿潜力。结果显示，中国西南滇黔桂地区水系沉积物锂含量平均值为46. 7×10-6，显著高于全国背景值32×10-6。以57. 0×10-6为异常下限，共圈定9个锂地球化学省，与已知的沉积型锂矿床分布具有良好的对应性。同时，锂异常浓集区与某些特定时代和岩性的地层分布密切相关。区内水系沉积物中锂元素含量受到岩石锂含量制约，以碳酸盐岩为主的构造单元水系沉积物中的锂显著次生富集，以陆源碎屑岩为主的构造单元内水系沉积物中锂富集程度较弱。综合分析认为，西南滇黔桂地区锂异常带的形成受区域岩石类型、次生富集作用和气候条件等多重因素制约。该研究对了解西南滇黔桂地区锂元素次生聚集就位机制和指导沉积型锂资源的找矿勘查具有重要的参考意义。

Temporal and spatial distribution characteristics of lithium geochemistry and prospecting prediction in the key resource prospecting new area of Yunnan, Guizhou, and Guangxi in Southwest China

Lithium has attracted much attention because of its wide application and irreplaceability in the field of new energy. In the past, lithium resource exploration was mainly concentrated on the hard rock and brine type lithium resources, and less work was carried out on the sedimentary-type lithium resources. This paper selected the Yunnan, Guizhou, and Guangxi regions in Southwest China as the research area to study the temporal and spatial distribution characteristics of lithium in rocks and stream sediments, to shed light on the regional mineralization potential of sedimentary-type lithium deposits. The results show that the average lithium content of sediments in the study area is 46.7×10^-6, which is significantly higher than the national background value of 32×10^-6. Taking 57.0×10^-6 as the lower limit of anomaly, 9 lithium geochemical provinces were delineated. The lithium geochemical provinces spatially correspond well to the distribution of proven sedimentary-type lithium deposits. Meanwhile, it is found that the abnormally concentrated areas are closely related to the distribution of some formations with specific age and lithology. The lithium content of the stream sediments in the area is restricted by the lithium content of the rock. In the carbonate-dominated structural units, secondary enrichment of lithium in stream sediments was significant. Lithium enrichment in the stream sediments in the tectonic units dominated by terrigenous clastic rocks is relatively weak. Comprehensive analysis suggests that the formation of lithium anomalous belts in southwestern Yunnan, Guizhou, and Guangxi is restricted by multiple factors including regional rock types, secondary enrichment, and climatic conditions. This study is significant for understanding the mechanism of secondary accumulation of lithium in the southwestern Yunnan, Guizhou, and Guangxi regions and guiding the exploration of sedimentary-type lithium resources.