Ore-forming fluids characteristics of quartz-vein tungsten deposits in southern Jiangxi Province

Southern Jiangxi is one important cluster of tungsten deposits in China, especially for hosting well developed quartz-vein tungsten deposits. Through analyzingthe latest research achievements of fluid inclusion types, ore-forming fluids characteristics of the quartz-veins tungsten deposit, microthermometry and Raman spectroscopy, and combined with research results of C, H, O and Sr isotope compositions, this study discussed the characteristics of ore-forming fluids of quartz-vein tungsten deposits in southern Jiangxi Province, with an emphasis on the fluid evolution during the mineralization of quartz-vein tungsten deposits. The ore-forming fluids indicated by this study would originate from magmatic waters with the ore-forming fluid evolution beginning at magmatic hydrothermal transitional stage of high temperature and high salinity. The temperature and salinity of fluids related to wolframite mineralization are around 260～360℃ and 4～9 wt%NaCl eq., respectively, suggesting that the ore-forming fluids belonged to a mid-low salinity hydrothermal system enriched in SiO₂, volatile components and ore-forming elements. The ore-forming mechanism in this area was dominated by fluid boiling and mixing, with minor deposits resulting from the ore precipitation due to fluid cooling.