| The Lengshuikeng Ag-Pb-Zn deposit lies in the south side of suture zone between theYangtze block and the South China block,the northeast margin of the South China plate,southeastmargin of the QinHang metallogenic belt,the Wugongshan-Kuaijishan front overthrust belt.ItsAg-Pb-Zn scale is super large gold deposit,and associated copper-gold poly-metal minerals hasinfluence in the world.The Lengshuikeng Ag-Pb-Zn deposit has a unique style of mineralizationcharacteristics,the typical porphyry-type Ag-Pb-Zn ore body is divided into three ore block:Yinluling,Baojia,Yinzhushan,the stratiform silver lead-zinc mine body is composing ofYinglin,Xiabao,Yinkeng three ore block.Porphyry type mineralization in a plane roughlynorth-east zonal distribution,lenticular orebodies along the contact zone of granite porphyry and invivo distribution,consistent with porphyry occurrences.Stratiform ore body positioning spacestrictly limited to Late Jurassic volcanic breccias,and mineralized breccia layer of the sameoccurrence,horizontal or gently inclined output,slightly undulating,layered-bedded.Based on the work of predecessors,this work took the ore body as the main researchobject,and gave attention to other ore block by adopting macroscopic and microcosmicmethods.Mainly on the mineral characteristics,which is including the ore type,ore fabric,chemicalcomposition,and metallogenic conditions of the ore deposit are discussed in detailed research.According to the ores’ structure characteristics,the ores can be divided into fine disseminatedtype ore,fine vein type ore,veinlet disseminated type ore,vein type ore,block ore; according to thedifferent useful components and content in the ore,the ores can be classified into silver ore,lead zincore,copper ore,Iron and manganese silver ore,Iron manganese,lead and zinc ore; the ores’ structuremainly include disseminated ore,vein structure,block structure,brecciated structure,crumbstructure,banded structure and a small amount of skin shell structure; the ore texture mainly includethe replacement of crystalline texture,solid solution separation texture,pressure texture and volcanicsedimentary-metamorphic texture.Main metallic minerals in the ore are mainly of sphalerite,galena,pyrite,chalcopyrite,arsenopyrite,pyrrhotite,sulfide minerals etc,acanthite,naturalsilver,sulfur silver tin mineral,pyrargyrite,kustelite,electrum,native gold,silver gold mineralsetc,,iron manganese carbonate minerals,magnetite,hematite,iron manganese minerals etc.The maincarrier minerals of silver are galena,sphalerite and pyrite,the other are given priority toacanthite,silver minerals,disseminated form of silver crystal gap,cracks,inclusions silver,silver evenscattered raw silver,silver; Lead,zinc mainly respectively occurre in galena,sphalerite,; the mostimportant minerals content in iron and manganese in mining area are iron manganese carbonateminerals and magnetite; to copper,copper’s content in copper ore is highest,with chalcopyrite formis given priority to,or embedded throughout sphalerite and pyrite; gold content is similar in all kindsof ores,ores according to the content in increasing order are iron ore for tables-silver ore-lead-zincore-iron manganese silver ore-copper sulfide ore.According to field output characteristics,wall rockalteration,ore type,ore fabric,ore mineral paragenetic association characteristics of porphyry typeore body and layer type ore body in the ore deposits,the ore deposit metallogenic process could bedivided into volcanic eruption-sedimentary mineralization period,hydrothermal mineralizationperiod,supergene period.Research results mineralization conditions of the following aspects:regional geologicalbackground,mine structural conditions,magmatic rocks conditions surrounding conditions.Areanorth east,north west trending faults jointly controlled the Yuefengshan area volcanic rift basinevolution,control magmatic rocks ejected,intrusive volcanic activity and continental sedimentarybasins Fe,Mn ore and stratiform ore formation；shallow region of acidic porphyry intrusive controlof the porphyry silver lead and zinc metallogenic specialization.Level structure can be divided intothree sequences: regional faults and volcanic structure,regional structure of the secondary faultsystem,the contact zone,fractured zone,breccia ore ore belt structure.Mineralization can be dividedinto before breaking rupture which is F1,mineralization of fracture which is F2,fracture aftermineralization which is NW-trending fault.Porphyry ore-magmatic zircons measured weightedaverage age of150.3±1.6Ma(MSWD=1.3) by the LA-ICP-MS U-Pb method,represents a porphyrytype mineralization mineralization age,description porphyry ore then formed later than thestratiform ore bodies; Ore-bearing porphyry remelting by the crustal evolution of the formation ofmagmatic differentiation,both ore fluids carry the body,but also the ore rock.Jurassic system SwanLake Ridge on group drumming is top volcanic rocks directly lead-zinc depos its of silver,theformation of a layered ore provided the material preparation and storage space.Mineralizationoccurs mainly in conditions of the low temperature(113~383℃) and ultra shallow(1.5kbar),thesalinity changed from high to low. |
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