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云南会泽铅锌矿床是扬子块西南缘川―滇―黔接壤区的铅锌银多金属矿集区已探明的唯一超大型铅锌矿床,矿床规模大(Pb+Zn探明储量超过500万吨)、品位高(Pb+Zn平均品位大于25%)、伴生元素多(Ag、Ge、Cd、Ga等),有很高的研究和经济价值。本文在总结该矿床地质特征、成矿流体性质及来源基础上,探讨了成矿流体迁移和沉淀机制。研究表明,低温(150～200℃)条件下,Zn主要以硫氢化物络合物迁移,少量呈氯化物络合物形式;Pb主要以氯化物络合物,少量以硫氢化物络合物形式进行迁移;高温(300～400℃)条件下,Pb、Zn主要以氯化物络合物的形式进行迁移。流体混合作用导致成矿流体温度降低,还原硫和Cl-浓度降低,pH值升高和氧逸度降低是成矿元素沉淀的主要机制。
The Huize Pb-Zn deposit in Yunnan Province is the only ultra-large lead-zinc deposit that has been identified as the lead-zinc-silver polymetallic ore deposit in the Sichuan-Yunnan-Guizhou border region of the southwestern margin of the Yangtze block. The deposits are large in size (Pb + Zn proven reserves exceeding 500 Tons of tons), high grade (Pb + Zn average grade greater than 25%), associated elements (Ag, Ge, Cd, Ga, etc.), a high research and economic value. Based on the summarization of the geological characteristics of the deposit, the nature and source of ore-forming fluid, the mechanism of migration and sedimentation of ore-forming fluid is discussed. The results show that Zn migrates mainly as hydrosulfide complex at low temperature (150 ~ 200 ℃), while a small amount is in the form of chloride complex. While Pb mainly takes chloride complex and small amount of hydrosulfide complex Pb and Zn migrated mainly in the form of chloride complexes under high temperature (300-400 ℃). The mixing of fluids led to the decrease of the temperature of ore-forming fluid, the decrease of the content of reduced sulfur and Cl-, the increase of pH and the decrease of oxygen fugacity.