广西晚二叠世典型聚煤盆地中锂、镓丰度及富集因素

针对广西晚二叠世聚煤盆地中锂、镓元素地球化学异常问题，选取扶绥和贤按两个典型晚二叠世煤田，通过系统取样测试，研究煤系中锂、镓丰度，并结合成矿地质背景，分析煤中锂、镓的富集控制因素。结果表明:研究区锂和镓均有一定的工业前景，扶绥煤田锂和镓的平均丰度分别为83.5 μg/g和30.8 μg/g；贤按煤田锂、镓丰度分别为199.1 μg/g和33.4 μg/g。锂主要富集于合山组底部K₁煤层、炭质泥岩及铝土岩段，而镓在合山组底部各岩性中的丰度并无明显差异。云开古陆及周边中酸性火山岩是锂、镓物质的基础来源，合山组底部高铝沉积岩系可能是合山组K₁煤层中锂、镓的直接物源。镓元素在各岩体之间的迁移比较活跃，其物源区的含量水平起主导作用，而锂元素的富集除了受控于物源外，沉积环境及后期地质作用的影响更为明显。研究成果为广西煤系中锂、镓资源的勘查预测及其综合利用提供科学依据。 

Lithium and gallium abundance and enrichment factors in typical Late Permiancoal-accumulating basin in Guangxi

Through systematic sampling and testing of two typical Late Permian coalfields in Fusui and Xian’an, starting with the lithium and gallium abundance of the samples, and combining with the metallogenic geological background of the Late Permian coal-accumulating basin in Guangxi, the factors controlling the enrichment of lithium and gallium in coal are analyzed. The results show that lithium and gallium in coal of both coalfield have certain industrial prospect. Lithium is mainly concentrated in K1 coal seam, carbonaceous mudstone and bauxite section at the bottom of Heshan Formation, while gallium abundance in each lithology at the bottom of Heshan Formation is not significantly different. The intermediate-acid volcanic rocks in the Yunkai paleocontinent and its surrounding areas are the basic source of lithium and gallium in the Late Permian coal measures in Guangxi. The high-aluminium sedimentary rocks at the bottom of the Heshan Formation may be the direct source of lithium and gallium in the K1 coal seam of the Heshan Formation. The migration of gallium between rock bodies is relatively active, so the content level of provenance plays a leading role in many enrichment factors. Besides provenance, lithium enrichment is more obviously influenced by sedimentary environment and later geological processes. The study result provides a scientific basis for the exploration, prediction and comprehensive utilization of lithium and gallium resources in coal measures in Guangxi.