【摘要】 银山矿床空间分布与燕山期陆相火山-次火山岩关系密切并具有显著的蚀变-矿化分带特征.蚀变带以英安斑岩为中心,从岩体内部向外水平方向依次为(弱)绢云母化英安斑岩带→黄铁绢英岩化英安斑岩带和千枚岩带→黄铁绢英岩化绿泥石化(碳酸盐化)千枚岩带→绿泥石化碳酸盐化千枚岩带→碳酸盐化绿泥石化火山碎屑岩带.原生矿化分带也以英安斑岩体为中心向外依次为铜矿化带→铜铅锌矿化带→铅锌矿化带→铅(银)矿化带,与蚀变分带呈明显的对应关系.热液蚀变过程中Ca,Mg,Na成分有被淋滤进入流体的趋向,Fe2+的降低与Fe3+的增高与Fe2+→Fe3+的氧化过程有关.成矿流体属酸性硫酸盐-氯化钠型流体.从黄铁绢英岩化英安斑岩→铜铅锌矿石→铅锌矿石,液相成分中K+,Na+,Ca2+,Mg2+,Cl-,F-含量均有降低趋势,SO2-4则有升高趋势,显示流体的氧化程度增大;气相成分中,CO2,CO,H2含量呈增高趋势,CH4含量呈降低趋势,表明流体在从岩体向千枚岩方向运移过程中反应CH4+2H2O→CO2+8H++8e和CH4+H2O→CO+6H++6e是向右进行的.银山矿床的形成经历了岩体初始富集和热液对流两个过程.对流热液主要来源于大气降水.矿床蚀变-矿化分带及其空间耦合关系与热液对流作用有关,对流热液在岩浆岩、地层等不同性质岩石间的循环导致了成矿物质多来源性.在热液对?更多还原

【Abstract】 Yinshan deposit is related closely to land facies’ lava-subvolcanic rocks of Yanshan period and has distinct alteration-mineralization zoning. The dacite-porphyries are centers of alteration-mineralization zoning. From the contract zone of magmatite outward,the alteration zone changes from beresitization zone to beresitization-chlorization zone, chlorization-carbonatization zone and carbonatization zone.Correspondingly,the mineralization zone can be divided into Cu zone,Cu-Pb-Zn zone, Pb-Zn zone and Pb（Ag） zone. Ca,Mg and Na have the trend of being leached from rocks and entering fluid during alteration process.Reduce of Fe³⁺and increase of Fe³⁺in alteration rocks are related to oxidation of Fe²⁺→Fe³⁺. The ore-forming fluid belongs to acidic sulfate-sodium chloride brine.From dacite-porphyries→Cu-Pb-Zn ore→Pb-Zn ore,the content of K⁺,Na⁺,Ca²⁺,Mg²⁺,Cl^-,F^- in liquid phase of fluid inclusion is going to decline while SO^2-₄content is increasing,indicating more oxidability in fluid.In gas phase,the content of CO₂,CO,H₂increases,and CH₄decreases,which is related to reaction of CH₄+2H₂O→CO₂+8H⁺+8e and CH₄+H₂O→CO+6H⁺+6e. Preliminary enrichment of ore-forming matter in magmatic rock and hydrothermal convection are the two processes in mineralization.The convecting fluid come mainly from meteoric water.The zoning and coupling of alteration-mineralization are related to hydrothermal convection.The circulation of convecting fluid during different kinds of rocks,leads to different source of ore-forming matter.The circulation of sulfur is an important reason of ore-forming metal elements’ activation-moving-accumulantion. .更多还原