CAJ | 학술논문

铜山大型铜矿床位于小兴安岭西北部,是中亚-兴蒙造山带北东段最著名的斑岩型铜矿床之一,矿体产于加里东期花岗闪长岩和中奥陶世多宝山组安山岩、凝灰岩中,铜矿化与硅化-绢云母化关系密切.流体包裹体研究表明,铜山铜矿床主要发育气液两相包裹体、含CO_2包裹体和含子矿物多相包裹体.成矿流体在形成过程中经历了早、中、晚3个阶段的演化.成矿早阶段发育气液两相水溶液包裹体和少量含子矿物多相包裹体,均一温度介于420℃～＞5500C之间,流体盐度介于13.72 wt%～59.76 wt%NaCl eqv之间;中阶段为铜山矿床的主成矿阶段,发育气液两相水溶液包裹体和含CO_2包裹体,均一温度为241℃～417℃,流体盐度介于2.96 wt%～14.04 wt%NaCl eqv之间,主成矿期成矿流体总体上属H_2O-CO_2-NaCl体系;晚阶段仅发育气液两相水溶液包裹体,均一温度为122℃～218℃,盐度介于3.71 wt%～15.96 wt%NaCl eqv之间,表明晚阶段有大气降水的混入.成矿早、中阶段的流体均为不混溶流体,流体沸腾作用是金属硫化物大量沉淀的主要机制.铜山矿床形成于陆缘弧环境.
동산대형동광상위우소흥안령서북부,시중아-흥몽조산대북동단최저명적반암형동광상지일,광체산우가리동기화강섬장암화중오도세다보산조안산암、응회암중,동광화여규화-견운모화관계밀절.류체포과체연구표명,동산동광상주요발육기액량상포과체、함CO_2포과체화함자광물다상포과체.성광류체재형성과정중경력료조、중、만3개계단적연화.성광조계단발육기액량상수용액포과체화소량함자광물다상포과체,균일온도개우420℃～＞5500C지간,류체염도개우13.72 wt%～59.76 wt%NaCl eqv지간;중계단위동산광상적주성광계단,발육기액량상수용액포과체화함CO_2포과체,균일온도위241℃～417℃,류체염도개우2.96 wt%～14.04 wt%NaCl eqv지간,주성광기성광류체총체상속H_2O-CO_2-NaCl체계;만계단부발육기액량상수용액포과체,균일온도위122℃～218℃,염도개우3.71 wt%～15.96 wt%NaCl eqv지간,표명만계단유대기강수적혼입.성광조、중계단적류체균위불혼용류체,류체비등작용시금속류화물대량침정적주요궤제.동산광상형성우륙연호배경.
The large-sized Tongshan porphyry copper deposit is located in the northwestern part of Lesser Hinggan Range,which is one of the most famous porphyry copper deposits in the northeast section of Central Asian-Mongolian-Hinggan orogenic belt.Its copper orebodies are mainly hosted in Caledonian granodiorite and Middle Ordovician Dubaoshan Formation andesite and tuff.Copper mineralization is closely associated with silicifieation and sericitization.In quartz veins three types of fluid inclusions are distinguished,namely aqueous two-phase,CO_2-bearing phase and daughter mineral-bearing multiphase inclusions.The evolution of the hydrothermal mineralization system includes three stages.Fluid inclusions of the early stage in quartz are mainly aqueous two-phase inclusion with minor daughter mineral-bearing multiphase inclusion,their homogenization temperatures and salinities vary from 420℃ to ＞ 550℃ and from 13.72 wt% to 59.76 wt% NaCl equivalent,respectively.The middle-stage fluid inclusions are mainly composed of aqueous twophase inclusion and CO_2-bearing phase inclusion,their homogenization temperatures and salinities vary from 241 ℃ to 417℃ and from 2.96 wt% to 14.04 wt% NaCl equivalent,respectively.The middle stage is main stage of ore-forming material enrichment,with affinities to H_2O-CO_2-NaCl fluid system.The late-stage fluid inclusions are characterized by aqueous two-phase inclusion,with homogeneous temperatures of 122℃ to 218℃ and salinities of 3.71 wt% to 15.96 wt% NaCl equivalent respectively,suggesting that this stage of ore-forming fluid is significantly mixed with meteoric water.Both early-and middle-stage fluids belong to immiscibility fluid,and the boiling action of ore-forming fluid is the dominant factor for metallic sulfide deposition.We conclude that the Tongshan porphyry copper deposit may occur in continental arc.