GEOLOGICAL CONDITIONS OF THE INTERSECTION-TYPE URANIUM METALLIZATION IN CENTRAL SOUTH OF LONGYUANBA COMPOSITE GRANITE BODY IN JIANGXI PROVINCE

The study area is located in the central south of the Longyuanba composite granite body, which lies in the south of Taoshan-Zhuguang uranium metallogenic belt. During Jurassic and Cretaceous, the tectonic environment in South China was in the transitional situation from compression to extension. Under such a background, the structure system in Longyuanba region is mainly developed in three groups in northeast, northwest and east-west directions. The NW-trending faults are perfectly filled by the intermediate-basic dikes, distributed with equal spaces. The boundaries between the dikes and the granitoids are obvious. The rock types of the dikes are diabase and lamprophyre. The uranium mineralization of the study area commonly occurs in the intersections of grey quartz veins and the intermediate-basic dikes. The dikes around the mineralization fade to brown or light gray from green-gray color, with alterations of silicification, hematitization, hydromicazation, limonitization, pyritization etc. Comprehensive analysis reveals that the uranium mineralization in the area is closely related to the intermediate-basic dikes in space, time and genesis. The study area is with good conditions and potentials for intersection-type of uranic mineralization.