Volcanic–intrusive system controls on the uranium metallogenesis in the Xiangshan volcanic basin based on 3-D joint inversion of gravity and magnetic data

SUMMARY The Xiangshan volcanic basin locates in southeast China hosts the world's third-largest volcanogenic uranium deposit. However, the structure of the volcanic system remains poorly resolved, limiting insights into the uranium mineralization. To address this, we conducted a joint inversion of gravity and magnetic data collected in the basin. Our inversion results reveal a southeast-dipping porphyroclastic lava conduit beneath the peak of Mount Xiangshan, characterized by low density and high magnetic susceptibility. A southwest-dipping volcanic conduit has also been identified beneath the rhyodacite crater in the Shutang area of the western basin. It connects to the porphyroclastic lava conduit in the deep. Both of these volcanic conduits are controlled by an EW-trending, low-density basement fault zone. This spatial relationship indicates that the volcanic eruptions in the western basin share a common subvolcanic plumbing system, which collectively acted as principal pathways for ore–forming hydrothermal fluids and uranium enrichment. These results underscore the role of volcanic-intrusive architecture in controlling the mineralization processes in the Xiangshan volcanic basin.