CO_2-CH_4流体与金成矿作用:以阿尔泰山南缘和穆龙套金矿为例  

CO_2-CH_4 fluids and gold mineralization:southern margin of Altay,China and Muruntau of Uzbekistan.

作　　者：徐九华[1] 谢玉玲[1] 丁汝福[2] 阴元军[1] 单立华[1] 张国瑞[1] 

机构地区：[1]北京科技大学资源工程系,北京100083 [2]北京矿产地质研究院,北京100012

出　　处：《岩石学报》2007年第8期2026-2032,共7页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(40672060;40572066);中国科学院地质与地球物理研究所矿产资源重点实验室基金资助。

摘　　要：造山型金矿的成矿作用与 H_2O-CO_2流体有着密切的联系。然而对阿尔泰山南缘和穆龙套金矿的流体包裹体研究表明,无水的 CO_2-CH_4流体在中亚成矿域中一些金矿床中具有同样重要意义。阿尔泰山南缘萨热阔布金矿包裹体的 X_(CH_4)达0.20～0.23,穆龙套金矿的 X_(CH_4)为0.07～0.23。CH_4扩大了流体不混溶的范围,有利于对 Au 的富集沉淀。CO_2流体在 Au 成矿中的重要作用至少包括了三方面的意义,即:缓冲流体 pH 值范围、提高流体中的 Au 含量并使其维持与还原硫的络合作用进行迁移;扩大超临界流体的温度范围;增加流体不混溶的区域。CH_4的加入扩大了流体不混溶的范围,有利于对 Au 的富集沉淀。Abstract Gold Mineralization in orogenic gold deposits is closely related to H2O-CO2 fluids. However, aqueous-free CO2-CH4 fluids are also important in some gold deposits of the Central Asia metallogeny province, based on fluid inclusion study on gold deposits of southern margin of Altay in China and Muruntau gold deposit in Uzbekistan. XCH4 of CO2-CH4 fluids at Sarekoubu gold deposit can be up to 0.20～0.23, and those in the Muruntau are 0.07～0.23. The role of CH4 in fluids is to enlarge the mixing area of fluids, and is in favor of gold enrichment. The significance of CO2 fluids in gold mineralzation includes three aspects, that is, including to balance pH range in ore-forming fluid and retain gold content in fluid so as to be complexed with sulfur, to enlarge temperature ranges of critical fluid, and to increase immiscible region of fluid. CH4 is significant for immiscibility, and plays an important role for gold enrichment.

关 键 词：流体包裹体 造山型矿床 CO2-CH4流体 

分 类 号：P618.51[天文地球—矿床学]