河北木吉村铜(钼)矿床辉钼矿Re-Os年龄及成矿流体特征  

Re-Os dating of molybdenite from the Mujicun Cu(-Mo) deposit in Hebei Province and characteristics of the ore-forming fluids

作　　者：陈超[1] 王宝德[1] 牛树银[1] 马国玺[2] 张建珍[1] 孙爱群[1] 马宝军[1] 陈志宽[2] 张福祥[1] 王自力[3] 

机构地区：[1]石家庄经济学院资源学院,河北石家庄050031 [2]河北省保定地质工程勘查院,河北保定071051 [3]天津华北地质勘查局,天津300170

出　　处：《中国地质》2013年第6期1889-1901,共13页Geology in China

基　　金：全国危机矿山项目(20109901;20089948);国家自然科学基金(40872137);我国典型金属矿科学基地研究(200911007);河北省科技厅项目(11277106D)联合资助

摘　　要：木吉村铜(钼)矿床位于河北省涞源县杨家庄镇木吉村,大地构造处于太行山脉中北段阜平幔枝构造的北东倾伏端,涞源哑铃状杂岩体连接处西侧上盘拆离带的次级断陷盆地中,已探明为一大型铜(钼)金银多金属矿床。在成矿地质背景的基础上,通过对不同钻孔不同深度矿心中5件辉钼矿Re-Os同位素的测定,获得模式年龄变化范围(143.2±2.2)Ma^(144.9±2.3)Ma,加权平均值为(144±1)Ma;并计算得出等时线年龄为(143.8±1.2)Ma,可厘定成矿时限为燕山晚期,这与太行山中北段区域多金属成矿大爆发事件基本一致。此外,根据流体包裹体特征和矿石辉钼矿Re含量,表明包裹体主要有气液两相包裹体、富气相包裹体、含二氧化碳包裹体和气液固多相包裹体4种类型。液相成分和气相成分均以H2O为主,其中气态包裹体还可见CO2;成矿温度大体为中温,盐度为中低盐度;成矿物质来源于地球深部。Located in Mujicun Village of Laiyuan County, Hebei Province, the Mujicun copper （ molybdenum ） deposit has been proved to be a large-size copper （molybdenum） - gold and silver polymetallic deposit in northern Taihang Mountains, geotectonically lying in the secondary fauked basin in the upper block of the detachment zone on the western side of Laiyuan dumbbell-shaped complex rock body, along the northern section of Fuping mantle branch structure. In order to study the metallogenic ages of the Mujicun copper （ molybdenum） deposit, the authors mainly analyzed the Re-Os isotopes of 5 pieces of molybdenite samples from different drill holes at different depths on the basis of the metaUogenic geological background, and obtained three important metallogenic ages, i.e., （143.2±2.2） Ma～（144.9±2.3） Ma （model age）, （144＋±1） Ma （weighted mean model age） and （143.8±1.2） Ma （isochron age）. The dating result suggests that the ore deposit was formed in the Late Jurassic of Yanshanian period, which is consistent with polymetallic metallogenic event in northern Taihang Mountains. In addition, according to the characteristics of fluid inclusions and the content of Re in molybdenite, this paper also indicates that the inclusions are composed of 4 types, i.e., gas-liquid inclusions, rich gas inclusions, CO2-bearing inclusions and gas-liquid-solid multiphase inclusions, in which H20 is the main composition for gas-liquid inclusions and rich gas inclusions. The ore-forming process took place under the condition of medium temperature and middle-low salinity, and the ore-forming materials were mainly derived from the depth of the earth.

关 键 词：辉钼矿 RE-OS同位素年龄 成矿流体 铜(钼)矿床 河北木吉村 

分 类 号：P597.3[天文地球—地球化学] P618.41[天文地球—地质学] P618.65