【作者】 李晓峰； 毛景文；

【Author】 Li Xiaofeng, Mao Jingwen (Institute of Mineral Resources, Chinese Academy of Geological Science, Beijing, China 100037)

【机构】 中国地质科学院矿产资源研究所；

【摘要】 四川大渡河金矿田位于扬子地台西缘金成矿带北段,受大渡河剪切带控制。本文以该矿田黄金坪、白金台子、黑金台子为例,根据对黄铁矿流体包裹体氮氲同位素组成测定结果,讨论了大渡河金矿田成矿流体的来源。结果显示,该金矿田黄铁矿流体包裹体中的³He/⁴He变化较小,为0.16～0.86Ra,而⁴⁰Ar/³⁶Ar的变化较大,为338～3288。本文认为大渡河金矿田成矿流体是地幔流体与地壳流体混合作用的结果,其中,以地壳流体占主导地位。而地壳流体端元又是大气降水来源流体与变质水来源流体的混合流体,并且流体的温度小于200℃。从矿田的南部到北部,大气降水加入成矿流体的比例越来越多。更多还原

【Abstract】 Helium and argon isotopic composition of fluid inclusions released by crushing pyrites are reported from the gold deposits along Daduhe River, Sichuan Province, China. The gold deposits are hosted in Precambrian basement of Kangding complex. 3He/4He ratios of fluid inclusions in pyrite range from 0.16 to 0. 86 Ra, whereas40 Ar/36Ar range from 332 to 3288. Analyses of He, Ar isotope from three gold deposits demonstrate the paleofluids were a mixture between mantle-derived fluid and crustal fluid, the crustal fluid is dominated. The endmember of crustal fluid is a consequence of metamorphic water mixing with meteric water, and the temperature of it is less than 200℃. From south to north in the Daduhe ore district, more and more meteoric water was involved in ore-forming fluid system.更多还原