Geological features and mineralization controls of pegmatite-type deposits at Fushui area, Shangnan County, Eastern Qinling Belt

A large number of granite pegmatite veins are exposed in the Shangnan area of the Eastern Qinling orogenic belt, some of which exhibit rare and rare earth metal mineralization, demonstrating exploration potentialand research significance.Through field geological investigations, petrographic observations, and geochemical analysis, the geological characteristics and mineralization law of the rare and rare earth metal granite pegmatite veins in the Fushui area of Shangnan were studied.The results show that the granite pegmatite veins are hosted in secondary tensional fractures of the Fushui complex.They belong to the peraluminous high-K calc-alkaline I-type granite series, and are genetically inferred to be derived from the Shangnan pluton.The mineralized granite pegmatites are dominated by niobium (Nb) rare mineralization and are classified as the NYF type in the terms of exploration direction.The mineralization is mainly concentrated in the intermediate zone of muscovite-microcline granitic pegmatite veins.The internal structural zoning from center to margin manifests as:Muscovite, albite, quartz zoneQuartz albite zone-Sodic aplite zone.Enhanced niobium mineralization is observed in zones with welldeveloped muscovitization (greisenization) and albitization.The study of this structural zoning enhances the diversity of ore-hosting types in pegmatite deposits at the Shangdan area.