地质通报2011，Vol.30Issue(5)：766-772,7.
CO2-H2O流体不混溶对Au溶解度的影响——以贵州省贞丰县水银洞金矿床为例
The effect of CO2-H2O fluid immiscibility on the solubility of Au: a case study of the Shuiyindong gold deposit, Zhenfeng County, Guizhou Province
摘要
Abstract
Based on the theory and method of thermodynamics, this paper discusses the effect of CO2-H2O fluid immiscibility on the solubility of Au. The results indicate that the ore-forming fluid in the Shuiyindong gold deposit was a kind of volatiles-rich (f∞2=707.946bar),acid (pH=3.71),reducing (fo2=5.012×10-36bar),mid-temperature (267℃) and overpressure (1800bar) gold-bearing fluid (a∑Au=3.744×10-8mol/L). When the closed layer of overpressure fluid was destroyed by the fault, pressure suddenly decreased (285～353bar), CO2-H2O fluid immiscibility occurred, and a large amount of CO2 overflowed. The fugacity of CO2 and O2 decreased (f∞2=8.054bar ,fo2=2.512×10-41bar), pH increased (pH=4.32), and temperature decreased too (224℃) with the fluid immiscibility. This led to the solubility of Au in ore-forming hydrothermal solution(a∑Au=3.790×10-9mol/L), rapid precipitation of Au, and the formation of ore deposit.关键词
水银洞金矿床/流体包裹体/CO2-H2O流体/不混溶作用/Au的溶解度Key words
Shuiyindong gold deposit/ fluid inclusion/ CO2-H2O fluid /immiscibility/ solubility of Au分类
天文与地球科学引用本文复制引用
李保华,顾雪祥,李黎,徐仕海,付绍洪,陈翠华,董树义..CO2-H2O流体不混溶对Au溶解度的影响——以贵州省贞丰县水银洞金矿床为例[J].地质通报,2011,30(5):766-772,7.基金项目
国家自然科学基金项目《滇黔桂地区卡林型金矿床流体不混溶成矿作用研究》(批准号:40873036)和《沉积盆地中金属成矿与油气成藏关系研究--以右江、兰坪盆地为例》(批准号:40930423) （批准号:40873036）
