Flour Stone Uranium Ore Field, Jiangxi Province Mineralization Mechanism

The Baimianshi uranium ore field is located in South Jiangxi Province. An analysis has been carried out on the regional geological background. Based on this analysis, a detailed study has been made on the characteristics of the uranium deposits and associated granites, volcanic rocks and ore-forming fluids in the ore field. The following are major achievements obtained in this thesis.1. The granites in the basement are the product of re-melting and modification of the thickened crust in the collision orogenic belt, and act as an excellent supply for uranium mineralization.2. Brannerite and H2 are discovered for the first time in the area, indicating the occurrence of mantle-derived fluids with high temperature in the region.3. The Deep faults and bimodal volcanic-intrusive activities result in formation of the channels for fluid movement, loci for ore deposit, and mineralizing agents for mineralization.4. The materials for uranium mineralization are mainly derived from crust-derived rocks.5. A continuous extraction of uranium from the upper crust with granites in the basement by mantle-derived fluids with little of ore-forming elements may be responsible for the remobilization and transformation of uranium.6. A mixing of metallogenic elements-rich fluid with groundwater in some draped places overlain by layers of basalt leads to the precipitation of ore-forming materials from a mixed fluid.7. There exist three episodes of uranium mineralization occurring in 160 Ma, 128 Ma and 103～86 Ma, respectively. The uranium ore deposits in the area are multi-original deposits formed by a compound metallogeny.