Characteristics and genesis of the ion adsorption REE deposit in Jiangbei metamorphic weathering crust, Southern Jiangxi Province

Through the petrographic, geochemical and mineral deposit studies of Jiangbei rare earth deposit in Southern Jiangxi, the results show the metallogenic mother rocks are mainly the metamorphic rocks of Xunwu Formation complex, with the lithology of granulite, schist and gneiss, among which the mica schist with the highest content of REEs serves as the most favorable parent rock, belonging to the LREE-enriched parent rock. The orefield is a low hilly terrain with average weathering crust thickness of 12.33 m. The orebody is mainly occurred in the completely weathered layer with the average thickness of 4.68 m and SRE₂O₃ grade of 0.035%～0.122%, belonging the ion adsorption rare earth deposit. The rare earth mainly comes from easily weathered water phosphate minerals and rare earth fluorocarbon minerals, with the chemical alteration index of weathering crust CIA>90%, indicating that the strong weathering contributes to the formation of deposit. The Huichang-Anyuan-Xunwu area where the mesometamorphic rocks are widely distributed has metallogenic potential of large rare earth deposits.