Study On The Mineralogical Characteristics And Genesis Of The Huanghuagou Lead-zinc Polymetallic Deposit In The Shaolang River Metallogenic Belt, Inner Mongolia

The Shaolanghe metallogenic belt in Chifeng area of Inner Mongolia is located in the accretion zone on the northern margin of the North China Plate.Affected by the Xilamulun River fault,Chifeng-Kaiyuan fault and Nenjiang fault,the regional metallogenesis is affected by volcanic activity in Mesozoic era and the superposition and transformation of several metallogenic domains,which results in the complex metallogenic background,excellent metallogenic conditions,rich and diverse deposits,large metallogenic intensity and multiple stages.Secondary characteristics.The research object of this paper is the typical Pb-Zn-Ag polymetallic deposit-Huanghuagou polymetallic deposit in Shaolanghe metallogenic belt.The mining area is located in the north of Shaolanghe fault zone and is obliquely penetrated by the NW-SE trending of Huanghuagou-Shanzuizi basement fault.The main host rocks in this area are rhyolite,dacite,tuff and tholeiite,which are distributed in Erlitu Formation,Manitou Formation and Baigaoyin Formation.The metallogenic period is in the Jurassic Period of Late Mesozoic.The ore bodies in the deposits are mainly hosted in the volcanic lavas and pyroclastic rocks of the Late Paleozoic and Mesozoic.They are distributed in the craters or volcanic channels in veins,reticular veins and radial shapes,and are often metasomatically graded with the surrounding rocks.Microscopic identification,EPMA and EDS analysis show that the main ore minerals of the deposit are galena,sphalerite,pyrite,hard manganese ore,and a small amount of siderite,pyrolusite,silver pyroxene and chalcopyrite.The ore-forming fluid of this deposit is a medium-low temperature fluid mixed with magmatic water and atmospheric precipitation,and the ore-forming material is extracted from surrounding rock during magmatic water intrusion.The main alteration mineral assemblages are:silica-rich mineral assemblages:quartz-opal-chalcedony,aluminium-rich mineral assemblages:albite-illite-sericite,manganese-rich alteration mineral assemblages:waxy silicomanganese-rhodochrosite and calcium-rich alteration mineral assemblages:siderite-rhodochrosite,and a small amount of barite,chlorite and other alteration minerals.Among the ore fabric characteristics,the main structural types are vein,reticulate vein,strip,disseminated,chlamydiform,stratiform and breccia.The main structural types are semi-automorphic grain structure,inclusion structure,mosaic structure,co-junction edge structure,silkworm structure,metasomatic residual structure and crushing structure.The fluid characteristics,ore minerals and altered wall rock assemblages of the deposit show that the deposit has the mineralization characteristics of low sulfur epithermal deposit.It is preliminarily inferred that the deposit is a low sulfur mixed hydrothermal vein type lead-zinc polymetallic deposit controlled by structure.