Research On Fluid Mineralization Of Skarn Tungsten Deposit Of Yunnan Province Malipo County Gouyanghemining Area

Scheelite deposit of Gouyanghe mining area is located in the east of tungsten-tinpolymetallicmetallogenic belt of Southeast Yunnan Laojunshan, tungsten orebodiesexist in the Nanyangtian rock group, ore body shape is simple, the output ismainlylayered like, and it is closely related to skarn in space. The metallogenicprocess from early to late stage is divided into3stages: skarn stage (early stage),degenerate alteration stage (middle stage) and quartz sulfide stage (late stage).Scheelite mainly formed in the degenerate alteration stage.Fluid inclusion of Gouyanghe tungsten deposit is mainly divided into fourcategories: rich liquid inclusions (Ⅰ), rich vapor inclusions (II), offspringmineralbearing polyphase inclusions (Ⅲ) and pure vapor inclusions (IV), in quartz minerals,these types are all developed, while in the sub-granate and epidote, only Ⅰ and Ⅱtwo types are developed. In early stage, the salinity of inclusions is1.74~9.60wt%,complete homogenization temperature is335~394℃, the peak is340~370℃, andwith even liquid; in the middle stage, the salinity of inclusionsis1.06~9.47wt%,homogenization temperature is253~340℃, the peak is260~270℃, and with evenliquid; in late stage, the salinity of inclusions is3.71~5.41wt%, homogenizationtemperature is162~269℃, most are250~260℃, and with even liquid. As can beseen, from early to late stage, homogeneous temperature, salinity and density of fluidinclusion showed decreasing trend. According to estimates, the density of the fluid ofGouyanghe tungsten deposit is0.988g/cm3on average, metallogenic pressure isbetween13.36~37.13Mpa, the average is26.66Mpa, the formation depth may be2km,belonging to epithermal deposit. Combined with the laser Raman test results of quartzfluid inclusions, show that the fluid inclusions in this area are mainly vapor fluidinclusions with middle temperature and low salinity.Melt inclusionsare found insub-garnets, in quartz, melt inclusions and fluid inclusions are found coexistent, it is a sign of melt and hydrothermal coexistingsystem, is the evidence of magma hydrothermal, it is also indicating that it wasin animmiscible state with melt and fluid coexistence. So that the formation of the skarn isprobably early Yanshanmelt assimilated calcareous rocks andthen formed immisciblemelts, bedding filling and formed skarn, belongs to magma metamorphic skarn.