Petrogenesis and tectonic significance of the Baipu granite porphyry in the Huangtian uranium deposit, northeastern Guangdong, South China.

Abstract

The genetic link between Late Yanshanian granitic magmatism and uranium mineralization in South China remains a subject of active investigation, with the petrogenesis and tectonic drivers of many uranium-hosting plutons being poorly constrained. To address this knowledge gap, we present an integrated study of the Baipu granitic porphyry in the Huangtian deposit, Northeast Guangdong, incorporating petrographic observations, zircon U-Pb geochronology, and whole-rock geochemistry. Our results show that the pluton was emplaced at 159.4 ± 1.4 Ma and is classified as a high-silica, potassic, strongly peraluminous S-type granite. It exhibits significant enrichment in LREEs and incompatible elements (e.g., Rb, Th, U), coupled with pronounced negative Eu and Sr anomalies. These geochemical signatures indicate derivation from the partial melting of psammitic crustal sources, with limited fractional crystallization, in a post-collisional setting triggered by Late Jurassic lithospheric delamination. We conclude that the Baipu porphyry is not merely spatially associated but is genetically linked to uranium mineralization, serving as both a metal source and a heat engine for ore-forming hydrothermal systems. This model underscores the high exploration potential for uranium deposits associated with S-type granites in similar extensional tectonic settings across South China.