| 甘肃鹰嘴山金矿床地质和成矿地球化学 |
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| 引用本文：.1998.Geology and metallogenic geochemistry of the Yingzushan gold deposit, Gansu Province[J].Mineral Deposits,17(4):297~306 |
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| 基金项目:国家计委科技找矿项目（JG9471902），原地质矿产部定向科研项目（DKJ95-16)和地质矿产部跨世纪人才基金 |
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| 中文摘要:鹰嘴山金矿床是北祁连山西段新发现的剪切带型金矿床。赋矿围岩为粉砂质板岩、英安质碎裂岩和安山质角砾凝灰岩等，蚀变以硅化和绢云母化为特征。成矿作用分为原生成矿期和表生氧化一次生富集成矿期。原生成矿又可分为微晶石英岩矿化阶段和脉状石英硫化物阶段，后者为主成矿阶段，表生成矿期硫化物氧化为硫酸盐类，金除了包含在硫化物中外，还以自然金充填石英颗粒之间或石英裂隙。在原生矿化蚀变过程中，硅质、碱质、CO2和REE带入了成矿体系。均一法测温表明成矿主要温度为320～200℃，成矿流体含有大量CO2，其氧同位素为岩浆水或深部流体为主。 |
| 中文关键词:脉状金矿床，地质特征，地幔流体成矿，北祁连山，甘肃鹰嘴山 |
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| Geology and metallogenic geochemistry of the Yingzushan gold deposit, Gansu Province |
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| Abstract:The Yingzuishan deposit, a gold deposit recently discovered in the western part of North Qilianshan Caledonian orogenic belt, is 15 km away from the Hanshan large-size gold deposit. The strata in the mine arc composed of volcanic, clastic arid carbonate rocks of Middle Cambrian Ge'ermogou Group. The host rock for the gold mineralization mainly comprises silty slate, dacitic cataclastic breccia and andesitic tuffbreccia. Totally 11 0rebodies have so far been found, of which the largest one is about 509 m long and 3 to 5 m wide with an average grades of 9.62×10-6. The orebodies extend 180°to 200°and dip 37°to 82°. Silicification， sericitization and ferrodolomitization are developed in the mine. Mineralization in the Yingzuishan gold deposit diplays two episodes, i.e, endogenetic and exogenetic episodes. The endogenetic episode comprises two stages of mineralization. Stage I mineralization comprises dense massive quartzite formed through replacement of ultrabasic rocks by auriferous hydrothermal solution. Stage II mineralization, the principal gold mineralization stage characterized by small airiferous sulfide cluartz veins, is commonly superimposed upon stage I mineralization. Geochemical studies of the ores and altered rock revcal that silicon, alkalinc components, CO2 and LREE were brought into the metallogenic system during mineralization and alteration, Homogenization temperature of stage II mineralization range from 320℃ to 200℃. Raman laser spectrum analysis of single inclusions shows the existence of abundant CO2 in the fluid. Oxygen isotope data suggest that the ore-forming hydrothermal solution responsible for the gold deposit was mainly derived from the magma of the mantle. |
| keywords:Yingzuishan vein gold deposit, geology, mantle-derived mineralization fluid, North Qilianshan, Gansu Province |
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