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The Shangfang deposit is a recently discovered large-scale tungsten deposit (66,500 t at 0.23% WO3), which is located near the western boundary of the Southeastern Coastal Metallogenic Belt (i.e., Zhenghe–Dafu fault), and adjacent to the northeast of the Nanling Range Metallogenic Belt. Unlike many other W–Sn deposits in this region that occur within or near the granites, the orebodies in the Sangfang deposit all occur within the amphibolite of Palaeoproterozoic Dajinshan Formation and have no direct contact to the granite. In this study, we carry out a thermal ionization mass spectrometer (TIMS) Sm-Nd isotope analysis for the scheelites from the orebody, which yields a Sm–Nd isochron age of 157.9 ± 6.7 Ma (MSWD = 0.96). This age is in good agreement with the previously published zircon U–Pb age (158.8 ± 1.6 Ma) for the granite and the molybdenite Re–Os age (158.1 ± 5.4 Ma) in the deposit. Previous studies demonstrated that the W–Sn deposits occurring between Southeastern Nanling Range and Coastal Metallogenic Belt mainly formed in the two periods of 160–150 Ma and 140–135 Ma, respectively. The microthermometry results of fluid inclusions in scheelite and quartz are suggestive of a near-isothermal (possibly poly-baric) mixing between two fluids of differing salinities. The H–O isotope results illustrate that the ore-forming fluids are derived from magma and might be equilibrated with metamorphic rocks at high temperature. The Jurassic granite pluton should play a critical role for the large hydrothermal system producing the Shangfang W deposit. Furthermore, the negative εNd(t) of −14.6 obtained in the Shanfang scheelite suggests for the involvement of the deep crustal materials. In general, subduction of the paleo-Pacific plate caused an extensional tectonic setting with formation of the Shangfang granites and related W mineralization, the geological background of which is similar to other W deposits in the Nanling Range Metallogenic Belt.

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A granite-related scheelite deposit has been recently discovered in the Wuyi metallogenic belt of southeast China. The veinlet-disseminated scheelite occurs mainly in the inner and outer contact zones of the porphyritic biotite granite, spatially associated with potassic feldspathization and silicification. Re-Os dating of molybdenite intergrowths with scheelite yield a well-constrained isochron age of 170.4 ± 1.2 Ma, coeval with the LA-MC-ICP-MS concordant zircon age of porphyritic biotite granite (167.6 ± 2.2 Ma), indicating that the Lunwei W deposit was formed in the Middle Jurassic (~170 Ma). We identify three stages of ore formation (from early to late): (I) the quartz-K-feldspar-scheelite stage; (II) the quartz-polymetallic sulfide stage; and (III) the quartz-carbonate stage. Based on petrographic observations and microthermometric criteria, the fluid inclusions in the scheelite and quartz are determined to be mainly aqueous two-phase (liquid-rich and gas-rich) fluid inclusions, with minor gas-pure and CO 2 -bearing fluid inclusions. Ore-forming fluids in the Lunwei W deposit show a successive decrease in temperature and salinity from Stage I to Stage III. The homogenization temperature decreases from an average of 299°C in Stage I, through 251°C in Stage II, to 212°C in Stage III, with a corresponding change in salinity from an average of 5.8 wt.%, through 5.2 wt.%, to 3.4 wt.%. The oreforming fluids have intermediate to low temperatures and low salinities, belonging to the H 2 O-NaCl ± CO 2 system. The δ 18 O H2O values vary from 1.8‰ to 3.3‰, and the δD V-SMOW values vary from -66‰ to -76‰, suggesting that the ore-forming fluid was primarily of magmatic water mixed with various amounts of meteoric water. Sulfur isotope compositions of sulfides (δ 34 S ranging from -1.1‰ to +2.4‰) and Re contents in molybdenite (1.45-19.25 μg/g, mean of 8.97 μg/g) indicate that the ore-forming materials originated mainly in the crust. The primary mechanism for mineral deposition in the Lunwei W deposit was a decrease in temperature and the mixing of magmatic and meteoric water. The Lunwei deposit can be classified as a porphyry-type scheelite deposit and is a product of widespread tungsten mineralization in South China. We summarize the geological characteristics of typical W deposits (the Xingluokeng, Shangfang, and Lunwei deposits) in the Wuyi metallogenic belt and suggest that porphyry and skarn scheelite deposits should be considered the principal exploration targets in this area.