Mantle-derived fluid and uranium mineralization: Evidence from the world-class Xiangshan uranium deposit, SE China

Abstract

Locally enriched mantle-derived fluids played an important role in the genesis of the world-class Xiangshan uranium deposit. Its ore-forming fluid and U, Th, alkali metals, LILE, REE and HFSE were mainly derived from locally enriched mantle sources. The Early Cretaceous back-arc extensional tectonic setting and deep boundary faults of the Gan-Hang basin enabled upward migration of the local enriched mantle-derived fluid. The mineralisation precipitated in multiple fracture zones in the Xiangshan volcanic rocks. The shallowly circulated meteoric water in fractures of volcanic rocks resulted in temperature decrease and solution dilution of the deep-seated ore-forming fluid and subsequent precipitation of uranium ores.