Geochemical Characteristics And Genesis Of The Hua'ao Bao The Silver-lead-zinc Polymetallic Deposit, Inner Mongolia, China

Silver-lead-zinc deposit of Hua'aobaote is located in the region of Bao ri ge si tai Su-Mu at Xi Ujimqin Qi in Inner Mongolia, and is a recently discovered hydrothermal veiny silver-lead-zinc polymetallic deposit related to magmatic activitis. The deposit has undergone three mineralization stage , including Quartz-Pyrite stage,Sphalerite-Galena stage and Arsenopyrite- Pyrite stage. Ag, Pb, Zn polymetallic mineralization in mine area is mainly located at the shoushangou strata of the Lower Permian, secondly at Times rhyolite and serpentinite. The rocks outcropped in the Mining area are mostly ultrabasic rocks in the late Variscan and vein rocks in Stage of Yanshan . Ore bodies of Hua'aobaote are located in North-East part of MeiLaote fracture.On the basis of geochemical data of silver-lead-zinc polymetallic deposit, this paper analyses the geochemical and fluid inclusion characters of mine area. Compared with the abundance of continental crust in eastern China, the host rocks in this area are strong enriched in Ag,As,Bi,Cd,Hg,In,Pb,Sb,Sn,Zn (K1≥5), enriched in W (1.2≤K1<5).Compared with compositions of the host rocks in this area, the mineralized rocks are strong enriched in Ag,Cd,Cu,Hg,In,Pb,Sb,Zn (K2≥5), enriched in As,Bi,Mo,Sn (1.2≤K2<5). It shows that the stratum of the mine area have some of the ore-forming potential. sulfide'sδ34S of ore bodies in Hua'aobaote ranges between -3.61‰~+1.21‰, the source of sulfur of this polymetallic deposit is relatively single,mainly derived from the deep. Ore deposits of lead isotope composition mainly derived from mantle-derived lead,partly reflects mixed features with lead related to magmatic. Ore-forming fluids are mixed hydrothermal solutions including mospheric precipitation and magmatic water.By the analysis of micro-measurement of fluid inclusions,quartz,calcite,sphalerite are mainly primary inclusions and rich-liquid phrase inclusions. Homogeneous temperature of fluid inclusion are between 146.7~274.3℃, the salinities w (NaCleq) are in the range of 0.54~8.52%, the density are in the range of 0.790～0.943g/cm3, the pressure are in the range of 9.60～20.26MPa and the mineralization depths may be about 0.96~2.03km.Ore-forming fluid is a typical non-saturated solution of low salinity and low density. The formation of Hua'aobaote deposits mainly due to a favorable strata and acidic subvolcanic magmatic rocks supply metallogenic material and heat source,and The north east Meilaote deep fracture provide channels and reserve mine place for ore fluid migration.Combined geological with geochemical characteristic,it can be concluded that the deposit may be a typical intermediate-epithermal veiny silver-lead-zinc polymetallic deposit associated with tectonic magmatic activity.