Geology, chronology and geochemistry of Niujiaowu tungsten polymetallic deposit in Northeast Jiangxi Province

The Niujiaowu deposit, situated within the eastern segment of the Jiangnan orogenic belt, stands as a significant mining domain wherein the exploration of tungsten polymetallic minerals has notably advanced in the northeastern region of Jiangxi Province in recent years. Tungsten ore bodies predominantly manifest within the contact zone delineated by granodiorite-porphyry and metamorphic sandstone, specifically within the Proterozoic Banqiao Formation. Presently unearthed tungsten resources have attained a medium scale, showcasing an average WO3 grade of 0.26%. The deeper resources hold immense potential for further exploration and development. This deposit exhibits a distinct zonal symbiosis, marked by the coexistence of shallow quartz vein-type tungsten ore and deep fine vein type tungsten ore, diverging from the conventional five-floor model commonly associated with quartz vein types. Consequently, it holds significant importance to conduct geochronological and geochemical research on its ore-bearing rocks and mineralogical studies on various types of scheelite, and finally to formulate a metallogenic model. Through meticulous geological surveying and meticulous cataloging of boreholes within the deposit, the initial determination revolves around discerning the mineral association and delineating the mineralized zonation characteristics unique to the Niujiaowu deposit. The zircon U-Pb age of the granodiorite-porphyry registers at 149.1 +/- 0.6Ma, signifying its origin as a result of expansive Yanshanian magmatic hydrothermal mineralization within the eastern region of South China. The granitic magmatic rocks, blessed with ore, prominently show calc-alkaline and peraluminous traits. Simultaneously, the rare earth elements present a distinct right-skewed partitioning pattern, characterized by a subtle negative Eu anomaly, an abundance of large ion lithophile elements like Rb, Th, and U, alongside a deficiency of high field strength elements such as Nb and Ti. Notably, the zircon epsilon(Hf)(t) exhibits concentration within the range of -15.2 similar to -3. 2, suggesting the ore-forming magma derives from the remelting of Paleoproterozoic shell source material. The REE characteristics of scheelite indicate that the mineral bearing hydrothermal fluids primarily stem from profound granitic magmas. Through the scrutiny of chronology, mineralogy and geochemistry, the metallogenic model delineating the Niujiaowu tungsten deposit, characterized by a combination of quartz vein-type and finely disseminated vein-type formations, was formulated. This model furnishes a novel theoretical framework for extensive tungsten mineralization investigations and profound exploration within South China.