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

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, namely I, 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 layers I, III, II and IV. Compared with average values for world claystone, the lithium mineralization layer I are highly enriched in Li, the II and III is enriched in Li, and the IV is slightly enriched in Li. The analysis of Al₂O₃–TiO₂, La/Sc-Th/Co and V–Ni–Th×10 diagrams indicate that most of the samples of lithium mineralization layer I, III and IV fall 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 Al₂O₃–TiO₂, La/Sc−Th/Co, V–Ni–Th×10 and Nb/Y–Zr/TiO₂ source rock discrimination diagrams indicate that the lithium mineralization layers of the Heshan Formation coal-bearing series in the Wanfu mining area mainly come from acidic and intermediate volcanic rocks related to the Emeishan Igneous Province and the Paleo-Tethys Permian magmatic arc.