Petrogenesis and factors controlling tungsten mineralization of Late Mesozoic granites from Xianxia intrusion and Zhuxiling tungsten deposit in Jiangnan tungsten belt, China

Globally, most tungsten deposits are closely and genetically related to granitic rocks, but only a small amount of granite can produce tungsten deposits. So far, there are still a topic of ongoing discussion about the controlling factors of ore-bearing granite formation. To investigate their controlling factors of the ore-forming granites, an inclusive research of zircon geochronology, apatite in-situ geochemistry, whole-rock major-trace elements and Sr-Nd-Pb isotopes was carried out for the Xianxia barren and Zhuxiling ore-forming intrusions in Jiangnan tungsten belt, China. Zircon UPb dating results show that Xianxia (133.8–140.1 Ma) and Zhuxiling (139.5–143.3 Ma) intrusions were emplaced in the Early Cretaceous. The Xianxia and Zhuxiling samples (SiO₂ = 62.04–70.40 wt%) predominantly are high-K calc-alkaline, weakly peraluminous monzogranite and syenogranite, exhibiting an affinity of weakly fractionated I-type granite, characterized by enrichment in LREEs, Rb, Th, and U, and negative anomalies in Eu (δEu = 0.68–0.90), Nb, P, and Ti. They also have relatively high Sr contents (247–549 ppm) and Sr/Y ratios (19.45–39.50), negative whole-rock εNd(t) values (−6.4 ∼ −5.0), high radiogenic Pb isotopic compositions, as well as high logfO₂ values (−22.03 to −11.35). The chemical and isotopic characteristics show that the Xianxia and Zhuxiling intrusions were likely derived from the mixing of Neoproterozoic crustal components with a little influx of mantle-derived magma. Compared with Xianxia samples (Kd ap-melt OH-F = 0.0047 (avg.) and Kdap-melt OH-Cl = 0.0912 (avg.) in apatite), Zhuxiling samples have higher halogen partitioning coefficient (Kd ap-melt OH-F = 0.0089 (avg.) and Kdap-melt OH-Cl = 0.1034 (avg.) in apatite), Sr and water contents (0.4762 wt% and 3.37 wt% of apatite and zircon), suggesting that it is more conducive to tungsten enrichment. A comprehensive discriminant analysis highlights that tungsten mineralization in weakly fractionated I-type granites is influenced by high-Sr content magma, increased alkalinity, elevated water and fluorine content, and active fluid dynamics. The results offer valuable insights into the conditions necessary for tungsten deposits in less evolved granitic systems, with broader implications for exploration strategies in similar geological settings.