Study On Fluid Inclusions And Isotopic Characteristics Of The Middle Xuefeng Gold-antimony Deposit In Xiangxi

Hunan is one of the important South China nonferrous metal deposit origin, the reputation of "hometown of non-ferrous metals". The gold antimony deposits are mainly distributed in Xuefeng,Xiangxi,Xuefeng gold and antimony metallogenic belt is Hunan Province and even in the South China area important polymetallic metallogenic belt, the distribution of many gold and antimony deposits. This paper of middle Xuefeng mountain gold- antimony ore belt in Xiangxi as the research object,the geological background of the region and the typical ore deposit geological characteristics on the basis of fluid inclusions and hydrogen and oxygen isotopic characteristics was studied in detail,discusses the source of ore-forming fluid and mineralization temperature.The main achievements of this paper can be summarized as follows:1.Middle Xuefeng mountain is located between the South China fold system and Yangtze Huai platform combined with zone, lying south of the whole Xuefeng arc structure. The gold antimony deposit in this region are widely distributed of strata, the main seam position Lengjiaxi group, Banxi group and the lower Sinian system, the main lithology of slate and siltstone. The area of the Structure is mainly controlled by EW-trending and NE-trending.2.The results of analysis of fluid inclusions temperature measurement shows that the freezing temperature of quartz inclusion values between-9.8 and-0.2? for the Longwangjiang; homogenization temperature changes from 82 to 300?; the salinity range from 0.4 to 22.2%; density ranges from 0.87 to 1.12g/cm3; the metallogenic pressure is between 70×105 and 234.9×105Pa; mineralization the depth of the ranges from 0.20 to 1.0km. The homogenization temperature changes from of quartz inclusions in the Fuzhuxi mining area is 105 to 300 ?; the salinity range from0.4 to 12%; the density ranges from 0.80 to 0.98g/cm3; the metallogenic pressure is between 69.7 ×105and 329.1×105Pa; metallogenic depth of 0.20 to 1.1km. The freezing temperature of quartz inclusion values between-8.4 and-4.5? for the Changziping; range ofhomogenization temperature 147 to 310?; the salinity ranges from 7.17 to 12.16%; the density ranges from 0.81 to 0.99 g/cm3; the metallogenic pressure is between 105.99×105and 342.10×105Pa; metallogenic depth of 0.50 to 1.14 km. To sum up three mining areas indicate that the characteristics of metallogenic fluid in the study area mainly in medium low temperature, low pressure, low salinity,medium density and surface hypabyssal metallogenic environment characteristics.3.Results according to the features of hydrogen and oxygen isotopes in the study area in the mining area, the d 18OH2 Ovalue between-0.06 and-8.92%;the d D values between-97.0 and-37.2%,These results show that the middle Xuefeng mountain of the ore-forming fluid was derived mainly from magmatic water and metamorphic water and participate in late accompanied by precipitation.The lead sources are mainly derived from the upper mantle and the lower crust, belonging to the mixed deep source lead; ore sulfur was mainly derived from crust and crust in the deep and surrounding rock, with characteristics of sulfur mixed. Overall that gold antimony ore forming material and fluid source is more complicated and multi-source.