| 云南大坪喜马拉雅期碰撞造山型金矿流体包裹体及其H-O同位素组成 |
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| 引用本文：.2009.Fluid inclusions and H-O isotopic compositions of Daping Cenozoic orogenic type gold deposit in Yunnan Province, China[J].Mineral Deposits,28(Z):13~27 |
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| 基金项目:国家自然科学基金（编号：40830425、40673045、40373027）、国家重点基础研究发展规划（973）项目（2002CB412610、2009CB421006）项目和高等学校博士学科点专项科研基金（编号：200805580031） |
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| 中文摘要:大坪金矿区金矿石可分为2种类型：晚元古宙闪长岩岩体中者（a）和D2灰岩地层中者（b），其中闪长岩岩体中金矿石可分为4个主要成矿期：白钨矿期（阶段Ia）、主成矿期（阶段IIa）、碳酸盐期（阶段IIIa）和无矿期（阶段Ⅳa）, 而灰岩地层中样品可分为2个期次：主成矿期（阶段IIb）和碳酸盐期（阶段IIIb）。本文利用显微测温和拉曼光谱分析，对大坪金矿晚元古宙闪长岩岩体和D2灰岩地层中含金石英脉中的含CO2流体包裹体和H-O同位素进行了研究, 结果显示：闪长岩岩体中金矿石主成矿阶段的包裹体中气相组成为CO2、N2和C2H4，盐度w(NaCleq)为4.80 % ~ 12.23 %，完全均一温度290.6 ~ 460.1℃，而灰岩地层中主成矿阶段的包裹体气相组成为CO2和CH4，盐度w(NaCleq)为0.63 % ~ 8.66 %之间，均一温度249.6 ~ 360.7 ℃。比较而言，灰岩中主成矿期金矿石流体包裹体的均一温度和盐度均较闪长岩中者为低，而两者成矿流体的δD-δ18OH2O组成区别不大，均主要落在原生岩浆流体和变质流体范围内，显示两者成矿流体来源基本一致，均主要来自下地壳和上地幔，但闪长岩中金矿成矿早于灰岩中者。 |
| 中文关键词:地球化学 含CO2流体包裹体 氢氧同位素 喜马拉雅期造山型金矿 大坪金矿 哀牢山金矿带 |
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| Fluid inclusions and H-O isotopic compositions of Daping Cenozoic orogenic type gold deposit in Yunnan Province, China |
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| Abstract:Gold ores in the Daping gold deposit in Yunnan Province may be divided into two types: (a) Late Proterozoic diorite hosted; (b) Middle Devonian (D2) limestone hosted. Mineralization in the type a can be divided into four stages: scheelite stage( Ia), main metallogenic stage (IIa), carbonate stage (IIIa), and barren stage (IVa), while that in the b can only divided into two stages: main metallogenic stage (IIb) and carbonate stage (IIIb). In this study, microthermometric measurement and Laser Raman analysis were performed for the CO2-bearing fluid inclusions in the auriferous quartz veins in Daping gold deposit, and their H-O isotopic compositions were also determinated. The results show that the gaseous phases of fluid inclusions in main metallogenic stage of diorite hosted gold ores (IIa) are composed mainly of CO2, N2 and C2H4, and the salinity w(NaCleq) and homogenization temperature th are 4.80 % ~ 12.23 % and 290.6 ~ 460.1℃，while the gaseous phases of fluid inclusions in main metallogenic stage of limestone hosted gold ores (IIb) are composed mainly of CO2 and CH4, and the salinity and homogenization temperature are 0.63 % ~ 8.66 % and 249.6 ~ 360.7℃. Comparatively speaking, the Th and salinity in the type b ores are lower than those in type a, but δD-δ18OH2O compositions of ore-forming fluids in the two different type gold ores are nearly the same, both of them were projected in the fields of primary magmatic water and metamorphic fluid, suggesting that the ore-forming fluids in the different gold ores in the Daping mine might have derived from same source: lower crust and upper mantle. The gold mineralization in the diorite hosted ores may be earlier than the limestone hosted. |
| keywords:geochemistry, CO2-bearing fluid inclusions, H-O isotopic composition, Cenozoic orogenic type gold deposit, Daping gold deposit, Ailaoshan gold belt |
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