Geological characteristics and mineralization of the granite-type uranium deposits in south China

Basing on systematizing the predecessors' achievements in prospecting and research on granite-type uranium resources in our country for more than fifty years,and applying research means such as geochemistry and induction of objective geological phenomena,the geological characteristics of the granitetype uranium deposits in south China are summarized as follows:The uranium-producing intrusions belong to composite massifs,the uranium-producing granites possess characteristics of intracontinental S-type granites,large time differences are shown between mineralization and diagenesis;ore-forming is obviously controlled by geological interfaces.Basing on understanding the dynamics processes ofsource,transportation and aggregationin the uranium mineralization,focusing on the source of ore-forming materials and the evolution of ore-fluid system,the granite-type uranium mineralization in south China is explained.It is believed that the source of ore-forming materials was originated from the regional Late Sinian and Early Cambiran uranium source beds,the invasion of vein rock after large-scale magmatic activities prompted the regional fluids to locally evolve to ore-forming fluids,which were driven by gravity and buoyancy and were transported by faults acting as important migration channels,and the change of physical-chemical conditions of the fluids caused the precipitation of ore-forming materials.