| 江苏观山铜铅金矿床成矿流体地球化学和成因 |
| 点此下载全文 |
| 引用本文：梁业恒，孙晓明，翟 伟,马 春，吴志强，丁存根，王堂喜,李爱菊，梁金龙.2008.Geochemistry of ore_forming fluids and genesis of Guanshan Cu_Pb_Au polymetallic deposit in Jiangsu Province [J].Mineral Deposits,27(5):605~612 |
| Hits: 2195 |
| Download times: 1633 |
|
| 基金项目:江苏省有色金属华东地质勘查局委托研究项目 |
|
| 中文摘要:观山铜铅金矿矿石中含有4种类型的流体包裹体：(Ⅰ)纯液相水溶液包裹体;(Ⅱ)富液相气液两相水溶液包裹体;(Ⅲ)富气相气液两相水溶液包裹体;(Ⅳ)纯气相包裹体。它们的气相分数变化较大，显示，成矿过程中可能发生过沸腾作用。 流体包裹体的显微测温结果显示，成矿流体的冰点温度为-0.3℃～-4.7℃，流体盐度w(NaCleq)变化范围为0.48%～7.39%，均一温度为133～304℃，对应流体密度为0.70～0.98 g/cm3。同位素测定显示成矿流体的氢氧同位素组成分别为δD水＝-810‰～ -900‰，δ18O水＝0.1‰～2.3‰，说明成矿流体主要为大气降水,但在矿体深部可能有少量岩浆水的加入。热液方解石碳同位素δ13C方解石＝-1.2‰～2.9‰，显示其中的C主要来源于流体对流循环过程中对基底岩石中碳酸盐地层的溶解。综合成矿地质特征、成矿流体的证据与围岩蚀变类型，初步推断观山铜铅金矿为高硫型浅成低温热液金属矿床，沸腾作用可能是引起矿质发生沉淀富集成矿的重要因素之一。 |
| 中文关键词:地球化学 流体包裹体 氢氧同位素组成 浅成低温热液矿床 观山铜铅金矿 |
| |
| Geochemistry of ore_forming fluids and genesis of Guanshan Cu_Pb_Au polymetallic deposit in Jiangsu Province |
|
|
| Abstract:Four types of fluid inclusions were recognized in the Guanshan Cu_Pb_Au deposit, i.e., (Ⅰ) liquid aqueous inclusions, (Ⅱ) liquid_rich two_phase fluid inclusions, (Ⅲ) gas_rich two_phase inclusions, and (Ⅳ) pure gaseous inclusions. Different types of inclusions with remarkably varied vapor/liquid ratios exist together, implying that boiling might have occurred during mineralization. Microthermometric measurement of the fluid inclusions show that the ice melting temperatures range from -0.3℃ to -4.7℃, and the corresponding salinities vary from 0.48 wt % to 7.39 wt% NaCleq. The homogenization temperatures range from 133℃ to 304℃, with densities from 0.70 to 0.98 g/cm3 Isotopic analyses show that δD.H2O and δ18O H2O values of the ore_forming fluids are -81.0‰ to -90.0‰ and 0.1‰ to 2.3‰, respectively, indicating that the ore_forming fluids are composed mainly of meteoric water, probably with the involvement of magmatic fluids. Carbon isotopic composition of hydrothermal calcites form the ore veins (δ13C calcite) are -1.2‰～2.9‰, suggesting that carbon in the ore_forming fluids was derived from carbonate sediments in the basement rocks. Geological characteristics, ore_forming fluid geochemistry and alteration assemblage suggest that the Guanshan Cu_Pb_Au deposit might be a high sulfidation type epithermal polymetallic deposit, and boiling seems likely to be the main factor for the deposition of ore solutions. |
| keywords:geochemistry, fluid inclusions, δD and δ18O composition, epithermal hydrothermal deposit, Guanshan Cu_Pb_Au deposit |
| View Full Text View/Add Comment Download reader |
|
|
|
