Research On Metallogenic Fluid Evolution Characteristics Of Lead-Zinc Polymetallic Deposit In Luziyuan,Zhenkang,Western Yunnan

Luziyuan lead-zinc polymetallic deposit located at Baoshan-Zhenkang plots lead-zinc polymetallic metallogenic belt Zhenkang ore district.In skarnization and Pb-Zn mineralization originated from interlaminar fracture zones of Dali rock.Of which gological studies show the main hydrothermal alteration could be atributed to two periods:early of skarn stage,late of skarn stage and low temperature hydrothermal periods.Studies on the typical fluid inclusions in minerals from various periods include rodonite formed in early of skarn stage,fluorite,quartz,sphalerite,calcite formed in skarn degradation and sphalerite,fluorite formed in Epithermal stage indicate that they are all brine system with peak homogenization temperatures of 234?316?,290?320?,112?342?,240?27?,180?270?,187?205?,145?180? and average salinities of 14.42%,10.52%,7.20%,7.26%,4.86%,5.36%,4.2%respectively.Raman microprobe analysis indicated thata majority of H2O and trace of CO32-exist in the forms of liquid phase of inclusion while a majority of CO2,N2 and CH4 could be detected from the gas phase.The evolution of ore-forming fluid of Himalayn periods is a evolution of decreased high temperature and moderate salinity to low temperature and salinity.Hydrogen and oxygen isotopes composition of the fluid inclusion in rhodonite and quartz indicates that the main fluid in early of skarn ore-forming was magmatic with the addition of a little water of meteoric,while the feature of late of skarn main ore-forming fluids was magmatic and mixed with a little water of meteoric and the metamorphic fluid.Sulfur isotope of the Luziyuan Pb-Zn deposit(?34S=10?13‰)is slightly lower than the layer(15‰).Which indicates that ore-forming hydrothermal sulfur isotope are mainly stratigraphic sulfur,have a small amount of mixed characteristics of deep source of sulfur.The lead isotopic composition show that lead has deep of mantle-derived magmatism related with mixed characteristics of crust source of lead.Luziyuan deposit is a mineral precipitation of various periods directly influenced by the temperature,salinity,pressure,component and derived different fluids of the high-temperature gas-liquid fluid magma.The deposit related to acidic concealed rock mass in deep tectonic hydrothermal skarn type Pn-Zn polymetallic deposit.