CHEN Jian1, XIANG Zhen-zhong2,3, WAN Bin1*, WU Long1, WAN Jiang1, WU Tao2,3, ZHOU En-ze1, ZHAO Long-qiao1, YANG Ru-chun1, GU Jing2
(1. The Sixth Geological Team, Guizhou Province Bureau of Nonferrous Metals and Nuclear Industry Geological Exploration, Kaili 556000, China;
2. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;
3. University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: Based on geochemical analysis of samples of the bauxite ores and wall-rocks from drill cores of the Datian bauxite deposit, in this study, we have explored the enrichment and distribution characteristics of Li, Sc, Ga, and rare earth elements (REE). The bauxite orebodies occurred in the Permian Liangshan Formation (Fm.), with a certain enrichment of Li and Ga in the ore-bearing rock series. Li is mainly enriched in clay minerals with relatively low Al concentration. Ga was not enriched in the earthy bauxite with relatively high Al content, though Ga contents are certainly correlated with Al contents in bauxite ores and bauxite-baring rocks in the profile of the deposit, and Ga was mainly enriched in the lower part of the clastic bauxite layer. It is inferred that the Ga distribution was influenced by the evolution of bauxite source rocks and was migrated and enriched with other al-bearing minerals down to the lower part. Sc mainly existed in the form of ion-adsorption, followed by the isomorphism. The left-inclined REE distribution patterns of bauxite ores suggest that the bauxite ore-bearing rock series experienced a certain fractionation between the light rare earth elements (LREE) and heavy rare earth elements (HREE) in the weathering and leaching processes of bauxite source rocks. Although the desilication was not developed, the de-iron activity resulted in the downward migration of Fe and REE of the bauxite-bearing rocks series to the bottom of the bauxite layer for the extreme enrichment of Fe and REE.
Keywords: Li, Sc, Ga and REE; geochemistry; bauxite; Datian; associated elements
ACTA MINERALOGICA SINICA Vol. 41, No.4/5, 2021, page 485-493
