Characteristics Of Fluid Inclusions And Its Research Significance Of Zhuxi Tungsten Polymentallic Deposit In Jiangxi Province

Zhuxi tungsten polymentallic deposit is located in Fuliang country,Jingdezhen city,the Northeast of Jiangxi Province,the tectonic location is located in the Jiangnan ancient island arc eastern part of the Yangtze plate and the the southeastern margin of Jiangnan orogenic belt.The deposit is a large-scale tungsten deposit which produced in Carboniferous-Permian shallow marine carbonate strata,the main type is skarn type.These layered and thick plate-like orebodies produced in granite porphyry?biotite gra-nite and Huanglong formation?Chuanshan formation carbonate strata contact zone,or the interlayer tectonic belt of the metamorphic sandstone in Shuangqiao Mountain Gr-oup.Wall rock alteration development,it mainly included skarn?epidotization?silicifi-cation and carbonation.The ore-forming period can be divided into hydrothermal mineralization?surface oxidation weathering two periods,hydrothermal mineralization period also can be div-ided into five stages,they are early skarn stage?late skarn stage?oxide stage?quartz-sulfide stage and quartz sulfide-carbonate stage.Zhuxi tungsten polymentallic deposit's inclusion types mainly are gas-liquid H₂O inclusions?gas-liquid H₂O inclusions containing daughter minerals and CO₂-H₂O three-phase inclusions.these inclusions mainly produced in quartz?fluorite?garnet?scheelite?diopside?calcite by isolated distribution?zonal distribution and Scattered distribution,their shapes are oval,nearly oval and cube-shaped,size more concentrated in the 5²5?m.Analysis of individual fluid inclusions shows that the vapor compone-nt of the inclusions mainly composed of H₂O?a certain amount of CO₂?a small amount of N₂?CH₄ and other gases,the liquid component is a brine solution containing A certain amount of SO₄^2-,but the salinity is low and the solid content is high melting point transparent minerals or capture crystals,such as calcite minerals or few cube shape halite crystal.The results of inclusions'micro thermometry and count are shown skarn stage average homogenization temperature is 345.7?,average salinity is 4.64wt%NaCl,av-verage density is 0.66g/cm³;oxide stage average homogenization temperature is 300.0?,average salinity is 4.44wt%NaCl,average density is 0.81g/cm³;quartz-sulfide stage average homogenization temperature is 172.1?,average salinity is 2.67wt%NaCl,av-erage density is 0.89g/cm³;quartz sulfide-carbonate stage average homogenization temperature is 143.9?,average salinity is 1.05wt%NaCl,average density is 0.93g/cm³.From early stage of mineralization to late stage of mineralization,the temperature and salinity of ore-forming fluid are decreasing,but the density of the fluid is increasing.T-he formation pressure of the deposit is 523.0bar,the mineralization depth about1.9km.The pH value decreases and the Eh value increases of ore-forming fluid from skarn stage to oxide stage,it indicates the metallogenic environment changes from a weak reducing environment to an oxidizing environment;the pH value increases and the Eh value decreases to negative value,it indicates the metallogenic environment changes from high oxygen oxidation-weak oxidation environment to low oxygen fugacity reduction environment.The early ore-forming fluid is mainly composed of magmatic water source,The later with the addition of atmospheric precipitation,the source of ore-forming fluid is mainly composed of magmatic water and atmospheric precipitation.The transport form of W in ore-forming fluid is mainly WO₂F₄^2-,followed by WO₄^2-.The main causes of tungsten precipitation is the interaction between tungsten containing fluids and carbonate minerals?skarn minerals,the combination of calcium and tungsten precipitation,the pH value increases and the temperature decreases of the ore-forming fluid,WO₂F₄^2-occurs decomposition,the formation of WO₄^2-and Ca²⁺combined to form scheelite,F^-and Ca²⁺combined to form fluorite,eventually enrichm-ent of mineralization.