贵州水银洞金矿床成矿物理化学条件及金的迁移和沉淀

摘要

对水银洞金矿床流体包裹体开展了研究和热力学计算,解析了该矿床成矿物理化学条件及金的迁移形式和沉淀机制.研究表明:金的主成矿温度为215℃～267℃,压力28.5MPa～37.2MPa;成矿流体具弱酸性(pH=4.312)、还原性(fo2＜10-35.315×105Pa).金在成矿溶液中主要以AuHS0等络合物形式进行迁移,HS-活度和氧逸度降低以及pH值升高是促使金沉淀的主要机制.%Based on the research of fluid inclusions and thermodynamics calculate in shuiyindong gold deposit, we have studied the physical-chemical conditions of mineralization, and the transportation form and deposition mechanism of the deposit. The research shows that the main temperature of gold mineralization is 215℃~267℃ ,and the pressure is 28. 5MPa~37. 2MPa;the ore-forming fluid with characteristics of weak acidity(pH = 4. 312), reducibilityCfq, < 10'35-315 X105 Pa);AuHS0 is the main transportation form of Au in the ore-forming solution; the main deposition mechanisms of Au are the decrease in the activity of HS~ and fq, and an increase in pH values.