Spatial distribution characteristics and metallogenic prediction of uranium deposits in Jiezhi Area in Nanxiong, Northern Guangdong

The Jiezhi Area in Nanxiong, northern Guangdong, as a crucial part of the South China uranium ore cluster, has recently revealed a unique metallogenic system comprising sandstone-type, intra-granite-type, and peripheral-granite-type uranium mineralization. Based on field geological surveys, geophysical inversion, and deposit anatomy, this paper demonstrates that the spatial distribution of uranium deposits in this area is controlled by a tripartite composite mechanism involving rock mass contact zones, fault structures, and lithological interfaces. Key findings include: ①sandstone-type uranium deposits are hosted in the redox transition zone of the Cretaceous Songshan Formation（K₂s）, formed under the control of a paleo-hydrodynamic system. ②Intra-granite-type uranium mineralization occurs in the NWW- to near-EW-trending silicified fracture zones and subsidiary fractures within the Beitou pluton, exhibiting multiphase hydrothermal superposition. ③Peripheral-granite-type uranium deposits are distributed near the contact zone between the Beitou pluton and Cambrian strata, influenced by the Lizhuang broom-shaped structural system. ④A ternary metallogenic model of “deep-source activation, structural extraction, and interface enrichment” is proposed. Integrated analysis identifies three prospective metallogenic zones and proposes new exploration targets.