地幔流体参与胶东金矿成矿作用的氢氧碳硫同位素证据  

The Relationship between Mantle-derived Fluid and Gold Ore-formation in the Eastern Shandong Peninsula: Evidences from D-O-C-S Isotopes

作　　者：毛景文[1] 李厚民[1] 王义天[1] 张长青[2] 王瑞廷[2] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质大学地球科学与资源学院,北京100083

出　　处：《地质学报》2005年第6期839-857,共19页Acta Geologica Sinica

基　　金：国家重点基础发展规划项目(编号G1999043211);国家自然科学基金委员会重点基金资助项目(编号40434011)的成果。

摘　　要：胶东地区金矿床可以分为三种类型,即石英脉型、破碎蚀变岩型和胶(州)—莱(阳)盆地北缘拆离带中的角砾岩型。挑选玲珑、焦家、三山岛、仓上、望儿山、大尹格庄、邓格庄、蓬家夼、发云夼和大庄子10个矿床中成矿主期的黄铁矿、绢云母和钾长石进行了硫、氢、氧同位素测试,还对个别矿床成矿晚期的碳酸盐矿物进行了碳、氧同位素测定,同时对比测定了玲珑花岗岩和郭家岭花岗闪长岩中黑云母和钾长石的氢、氧同位素,结果表明这些金矿虽然产出形式有差别,但都是同一深部流体库中流体上涌、与围岩发生强烈水岩反应和与地壳流体混合,通过交代和沉淀成矿。胶东金矿在形成时代上晚于侏罗纪玲珑花岗岩(160～150Ma)和白垩纪郭家岭花岗闪长岩(130～126Ma),与煌斑岩墙及其他中基性岩墙同时生成(121～114Ma),两者具有富CO2流体和伴随着以钾交代为特征的蚀变作用,都是中生代岩石圈快速减薄过程的地壳浅部响应。There are three types of gold deposits in the Eastern Shandong peninsula, the largest gold area in China, i. e. quartz vein, fracture altered and breccia types. The former two developed along a group of NE-trending faults and are hosted by Jurassic biotite granite intrusions dated 160- 150 Ma, Precambrian metamorphic rocks and Cretaceous granodiorite dated 130-126 Ma on the Precambrian crystalline basement. And the late one occurs around the northern margin of the Jiaojia-Laizhou Crtaceous basin and the mineralization is controlled by both the detachement fractures and NE-trending faults. In this study we chose 89 samples from ten gold deposits comprising the Linglong, Jiaojia, Sanshandao, Cangshang, Wanglershan, Dayigezhuang, Denggezhuang, Pengjiakuang, Fayunkuang and Dazhuangzi; the Linglong Jurassic biotite granite, Guojialing Cretacceous granodiorite, and Archaean gneiss for the systematic measurements of S, D, O and C stable isototpes. The analyses results of these isotopes reflect the three types gold deposits occur in different modes but deposition by the same mixtured fluid system derived from mantle fluid reservior incorporated with crust fluids by the strong interaction with the host rocks at 120 Ma. Their ore-forming age is later than both the Jurassic biotite granite and Cretaceous granodiotite, and overlaps with the age of diabase and lamprophyre dikes ranging from 121Ma to 114Ma. The hydrothermal fluids which is responsible to both gold mineralization and the retrograde alteration of the diabase and lamprophyre dikes is quite similar, belonging to CO2 and potashenriched fluid system, which is possibly the consequence of the Cretaceous lithospheric thinning and asthenosphere upwelling process in Eastern China.

关 键 词：氢 氧 碳 硫同位素 地幔流体 金矿床 胶东地区 

分 类 号：P618.51[天文地球—矿床学] P597[天文地球—地质学]