黑龙江省铜山斑岩铜矿床流体包裹体研究

Fluid inclusion study of the Tongshan porphyry copper deposit,Heilongjiang province,China

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℃～>550℃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。

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 silicification and sericitization.In quartz veins three types of fluid inclusions are distinguish...