论胶西北河西金矿床成因及其动力学条件  

Genesis and Dynamic Condition of Hexi Gold Deposit in Northwest Jiaodong Area

作　　者：徐贵忠[1] 应汉龙[1] 周瑞[1] 佘宏全[2] 闫臻[1] 王艺芬[1] 李兵 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国地质科学院矿产资源研究所,北京100037 [3]山东省第三地质勘查院,山东烟台264000

出　　处：《矿床地质》2002年第3期246-255,共10页Mineral Deposits

基　　金：国家重点基础研究项目 (编号 :G19990 43 2 0 7和G19990 43 2 0 3 )研究成果之一

摘　　要：胶东河西金矿床属于典型的蚀变岩型金矿床。金矿体赋存于玲珑黑云母花岗岩体内 ,并受北东向断裂构造带所控制。87Sr/86Sr的初始比值表明 ,玲珑黑云母花岗岩和郭家岭花岗闪长岩均为壳源深熔花岗岩。地质和同位素年代学资料表明 ,金成矿作用发生在早白垩世。据硫、氧同位素组成判断 ,河西金矿床的成矿作用可能与郭家岭花岗闪长岩的流体活动有关 ,其成矿温度以中温为主 ,成矿压力为 (12 0 0～ 14 0 0 )× 10 5Pa。河西金矿床的花岗岩、蚀变岩和矿石的稀土与微量元素分布模式明显相似 ,说明它们有着共同的成因 。The Hexi gold deposit, located in the Xincheng_Jiaojia gold field of Northwest Jiaodong peninsula, is a typical gold deposit of altered_rock_type. The orebodies were hosted in early Cretaceous Linglong altered biotite granite and controlled by NE_trending faults. The initial 87 Sr/ 86 Sr ratios demonstrate that both Linglong biotite granite and Guojialing granodiorite are derived from deep melted crustal materials. Geological and isotopic chronological data indicate that gold mineralization occurred in early Cretaceous. The sulfur isotope composition of ore minerals in the Hexi gold deposit implies that the sulfur materials for mineralization are mainly derived from the deep remelted granitic magma. Oxygen isotope is steady and varies in a very small range, suggesting that the source of hydrothermal fluids is steady. Based on characteristics of stable isotopic data, we can draw the conclusion that the metallization of the Hexi gold deposit is probably related to the fluid activity of Guojialing granodiorite. The metallogenic temperature is mainly moderate and the pressure is about (1?200～1?400)×10 5 Pa. The composition of the REE and trace elements shows that granite, altered rocks and ores have obviously similar REE and trace element patterns. This implies that they have the same genesis and are related to the remelting of the crustal granite. During the early Cretaceous period, The subduction of Kula_Pacific plate into the Europe_Asia plate caused the ascending of the mantle in Yishu fault zone and Jiaodong area, the thinning of lithosphere and the crustal extension. It should be pointed out that Yishu rift, Jiaolai stretching basin, large_scale tectonic_magmatic activity generated by above geological processes are important geodynamic conditions favorable for gold metallization in this area.

关 键 词：成矿作用 矿床成因 动力学条件 构造-岩浆活动 新城-焦家金矿田 金矿床 

分 类 号：P618.51[天文地球—矿床学]