Characteristics Of Fluid Inclusions And Genesis Of Changgou Gold Deposits In Hanyin County,Shaanxi Province

This paper is based on the project of prospecting and forecasting of key duty area in Changgou area of Shaanxi Shiquan-Xunyang gold deposit survey area,by constructing the study area-facies special geological mapping and related experimental research test,starting from the study of the characteristics of quartz veins in the study area,focusing on a uniform temperature of the fluid inclusions quartz veins different properties,salinity,density,composition characterized studied in detail,the capture pressure and depth of the fluid inclusions are estimated;Then,according to the formation conditions of the Changgou gold deposit,the structural conditions of the mineralization and the characteristics of the magmatic rock,combined with the ore-forming fluid properties and sources,ore-forming material sources and other factors,the mineralization process of the deposit is inferred,and the genesis of the deposit is determined;finally,according to the spatial distribution characteristics of the ore body,the prediction area of the mining area is deduced.Specific knowledge and achievements are as follows:1.The Changgou gold orebodies are mainly composed of mineralized alteration rocks and gold-bearing quartz veins in the shallow metamorphic schist rocks of the second lithologic layer of the Lower Silurian Meiziya Formation,which is mainly controlled by the ductile shear zone in the deformed metamorphic rocks of the Silurian area and its secondary secondary fracture zone.Ore body was lenticular or strip-like,in the plane showed the left column of the right column output,under the section was oblique left side,it is presumed that the Changgou gold mining area may have the oblique output of the ore body in the deeper part of the NW part of the known ore bodies K1 ~ K3 and K4 ~ K6.2.Changgou gold ore types include quartz vein type and structural alteration rock type,mainly in alteration rock type.The ore structure is mainly composed of scaly crystal structure and massive structure,construction including sheet structures,disseminated structure,vein structure,crumb structure and the like,mainly in a sheet configuration.,mainly in a sheet configuration.Silica,pyrite and biotite in the surrounding rock are closely related to gold mineralization.3.The fluid inclusions in the vein of Changgou gold ore are mainly composed of gas-liquid two-phase inclusions,and single-phase and three-phase fluid inclusions are rare.The homogenization temperature of the fluid inclusions is mainly concentrated at 210 ~ 280 ?,the salinity is mainly concentrated in the range of 6% ~ 12% NaCleq,the peak of the density range is between 0.75 ~ 0.95 g / cm3;the gas component and the liquid phase are mainly CO2 and H2 O.The ore-forming fluids are generally medium-low temperature,medium-low salinity,low density CO2-H2 O fluids.4.The development of the Changgou gold deposit corresponds to the three-stage quartz veins corresponding to the study area,compared with the characteristics of the quartz inclusions in the S2 phase and the S3 stage,the characteristics of the quartz vein and the mineral inclusions are similar to those of the quartz inclusions.The comprehensive analysis shows that the S2 fluid is the main ore-forming fluid of the Changgou gold deposit,and the S3 fluid is another fluid with little effect on the mineralization.5.By comparing the characteristics of rare earth trace elements in alteration rock ore,metamorphic schist,S2 quartz vein and diorite vein,metamorphic schist and alimentary rocks have homology,it is inferred that the source of ore-forming material in Changgou gold deposit should be the metamorphic rockof Meiguya Depression in Minzhi Formation.6.By analyzing a series of metallotectonic mine,display brittle-ductile shear zone has a profound impact on the mining of gold,it is concluded that the brittle-ductile shear zone is the main ore-controlling structure of the Changgou gold deposit.7.The tectonic setting,ore-controlling structure,magmatic rock,mineralization type,ore-forming fluid properties and metallogenic age of the integrated Changgou gold deposit,according to the characteristics of ore deposit structure and ore type of Changgou gold deposit,which is specifically defined as brittle-ductile shear zone alteration rock type gold deposit.