Geochemical Characteristics Of Skarn Minerals And Genesis Research Of Luziyuan Pb-Zn Deposit,Wester Yunnan

Baoshan-Zhenkang block in the "Sanjiang" metallogenic belt in SW China is located at the junction of Nujiang fault,Longling-Ruili fault and Kejie fault.Luziyuan deposit is a large Pb-Zn polymetallic deposit developed in this belt.Based on detailed field geological investigation, by means of petrography, Electron microprobe analyzing, rare earth element and fluid inclusion studying, conclusions are drawn as follows:(1)The analysis results of paragenetic association of minerals shows that the evolution of in Luziyuan deposits generally experienced three stages:Skarn stage, in which garnet, diopside, rhodonite, actinolite, epidote, chlorite and other minerals formed; hydrothermal mineralization stage, sphalerite, galena, quartz and calcite formed; supergene oxidation stage, some oxides formed.(2)Eelectronic probe components analysising shows that the garnet is mainly andradite and minor grossularite; That Mn/Fe ratio in pyroxene is often higher than0.1, indicates the mineralization type is lead-zinc mineralization in skarn deposits; Amphibole minerals belong to calcium amphibole, which is mainly actinolite, reflecting the characteristics of calcareous skarn; Rhodonite is a sign of lead-zinc mineralization; the chlorite is rich in iron and poor in magnesium; the sphalerite is formed under medium-high temperature conditions.(3)We made a systematic analysis on the rare earth elements of skarn, and dicsuss the rare earth elements geochemical characteristics, sources, formation mechanism and ore-tracing significance. The result shows that the skarn has characteristics of hydrothermal origin, and the metallogenic environment is a relatively reduction environment.(4)The fluid inclusions includes pure liquid inclusions, gas-liquid inclusions and few multiphase inclusions containing daughter minerals, which are found mainly in rhodonite, fluorite, quartz, sphalerite and calcite. The homogenization temperatures is100～340℃.And laser Raman indicates that the component of fluid inclusions is dominated by CH4、H2O、 N2、CO2etc.(5)Luziyuan lead-zinc polymetallic deposit is a hydrothermal filling metasomatic skarn deposit.