Geochemical Feature And Genesis Of Shihu Gold Deposit In The Middle Of Tai-hang Mountains

ShiHui Gold Deposit located TaiHang mountains polymetallic metallogenic belt ofwestern HeBei province. In Yanshanian the tectono-magmatic activity development,forformation of regional mineral afforded beneficial geological environment conditions.Thispaper systermatic reseach the Ore deposit geological characteristics,geochemicalcharacteristics and genesis of mineral deposit of ShiHui Gold Deposit from Regionalgeological background to Petrologist, mineral deposits, geochemistry of mineral deposits,Fluid inclusions geology and stable isotope geochemistry.Dark inclusions zircon U-Pb chronology studies show MaPeng rock mass intrusions inabout136Ma,belong to TaiHang tectonics and magma actinities product of Yanshanian. Thecharacteristic High Sr-Ba content, High ratio of Sr/Y and La/Yb,and high Mg and K indexreflect MaPeng rock mass form the basis of fractional crystallization product of enrichedmantle basic magma and the earth’s crust granitic magma; Dark inclusions may be basiteresidue of Magma mixing inhomogeneous chemical exchange.Analysis of deposit geological characteristics,author consider SN fracture structurecontrol form of ShiHui Gold Deposit, texture and structure of ores is complexity,sight textureinclude euhedral crystal-granular, subhedral-allotriomorphic granular texture, metasomaticrelict texture,pressure texture, poikilitic texture, emulsion droplet,etc; sight structure massivestructure, disseminated structure, brecciated structure, spotted structure,fine vein structure,vesicular structure; According to the field dodge and weave relationship of vein, thecharacteristic of paragenetic association of minerals and microscope, mineralization of ShiHuiGold Deposit could divide into4stage of mineralization(1) pyrite-quartz stage;(2)pyrite-quartz stage;(3)polymetallic sulfide stage;(4)quartz-carbonate stage;gold with mainlynative gold and electrum, gold and silver form embedded in pyrite, sphalerite, galena andchalcopyrite in sulfide minerals.Fluid inclusion reflect ShiHui Gold Deposit ore-forming fluidbelong to CO2-H2O-NaCl system,from early mineralization low salinity H2O-CO2type go bymain metallogenic stage rich CO2and H2O to late mineralization deficient CO2low salinityH2O solution evolute.In main mineralization the fluid temperature did not evidentchange,about for254.3～440.2℃,in late mineralization because atmospheric precipitationjoin in the fluid,the salinity and temperature obvious lower.Research of host strata and ore stable isotopes reflect metallogenic element coming fromdeep crust,FuPing group Tuanbokou formation as source rock provide gold element. Ore-forming fluid is influenced by atmospheric precipitation and metamorphic fluid mixedcharacteristics of multi-source hydrothermal magmatic hydrothermal fluid.