Geochemical Characteristics And Genesis Of The Laizhi Lead-Zinc Deposit In Guizhou

Wuzhishan Nayongzhi Pb-Zn Deposit,a large-size Pb-Zn deposit under north-westtectonic settings in the lead and zinc metallogenic zone in the northwest of Guizhou,is located at Southwest of the Yangtze paraplatform,the westen margin of Guiyang complex tection deformation zone and south adjacent of Youjiang orogenic belt.The area is surrounded by three deep faults,which are Ziyun-Yadu fault,Nayong-Xifeng fault and Anshun-Zhenyuan fault.The oreodies are hosted in Qingxudong Fromation dolomite of the series Cambrian or fault zone.his paper researches the geological characteristics of Nayong branch deposit geochemistry,combined with microscopic study mineralography,judge the matter source,by contrast,with the MVT type and SXDEX type lead-zinc deposit is summed up,the metallogenic model,under the guidance of further prospecting work.It is summarized as follows:The formation of lead-zinc deposits in the study area is controlled by the stratigraphic lithology of the mining area.The lead and zinc mineral in the Qingxudong formation.In fracture fracture type ore belt,ore controlling structure obviously.Through indoor microscope polishedsection identification,deposits in the mineral composition is simple,the main metal minerals are sphalerite,galena,pyrite,and gangue minerals are mainly dolomite,quartz and calcite.The metallogenic methods are mainly of metasomatism and filling,and the ore body is the pulse and lens output.The structure of the ore,such as granular structure,block structure,vein structure,concentric ring structure and strip-band-layer,impregnation,impregnation,breccia and net vein.Some of the minerals still retain the constitutive features of the protosedimentary and metallogenic processes,such as the laminar structure of the sparktite and the strawberry-like structure of pyrite.By lead and zinc ore trace and rare earth elements,S,Pb,C and O stable isotope test and analysis,show that the ore-forming material deposit is Liu Yuan detrital material to join,come minerals from the ore deposit formation may be even more ancient basement strata.The source of sulfur is a mixture of sulfates and mantle sources in Cambrian,and the formation mechanism is thermochemical reduction.The lead is derived from the lower basal strata and the orogenic belt,which has the characteristics of multiple sources and has no genetic connection to the basalt rocks in the adjacent area.The main source of carbon is Marine carbonate,and the formation of C02 in the mineral fluid is related to the dissolution of Marine salt.MVT type,with typical type SEDEX pb-zn deposit geology and geochemical characteristics after contrast that pb-zn deposit in this region is more close to the MVT type pb-zn deposit,preliminarily established the "sedimentary enrichment" ?transform ? metallogenic model.