张家口朱家洼钼矿床成矿流体特征及对成因指示  

Characteristics and genetic indication significance of fluid inclusions in the Zhujiawa molybdenum deposit

作　　者：李随民 李继超 李樋 全素桃[3] 胡志强[3] 李玉红[3] 王京[3] 陈树清[3] LI Suimin;LI Jichao;LI Tong;QUAN Sutao;HU Zhiqiang;LI Yuhong;WANG Jing;CHEN Shuqing(Hebei GeoUniversity,Shijiazhuang 050031,Hebei,China;No.2 Geoexploration Party,Henan Bureau of Geoexploration and Mineral Development,Zhengzhou 450018,Henan,China;No.3 Geological Party,Hebei Geological Exploration Bureau,Zhangjiakou 075000,Hebei,China)

机构地区：[1]河北地质大学,河北石家庄050031 [2]河南省地矿局第二地质勘查院,河南郑州450018 [3]河北省地矿局第三地质大队,河北张家口075000

出　　处：《中国地质》2020年第2期426-439,共14页Geology in China

基　　金：河北省国土资源厅项目(2013045650);河北省地矿局项目(454-0601-YBN-QEXZ)联合资助.

摘　　要：张家口朱家洼钼矿床是近年来华北地台北缘中段继内蒙古曹四夭特大型钼矿床之后发现的又一个规模可达大型的钼矿床。钼矿床主要呈半隐伏-隐伏状围绕分布于骆驼山岩体周边。本次对矿区2个钻孔中采集的11件富含辉钼矿的石英矿物,进行了包裹体岩相学、显微测温、包裹体气、液相成分及氢氧分析。结果显示:该矿床流体包裹体可分为4种类型:富液相包裹体、富气相包裹体、含子晶包裹体和富CO2三相包裹体。其中,富CO2三相包裹体分布较少,其余3种类型包裹体常见。含子矿物的包裹体均一温度、盐度分别在400℃和45%NaCl eqv左右;富液相包裹体均一温度平均值为277.43℃,盐度20%NaCl eqv左右;富气包裹体和富CO2包裹体均一温度分别为380℃和30℃;盐度较低,分别为6%NaCl eqv和2.04%NaCl eqv左右。气液相成分分析显示流体体系成分以H2O、Cl^-、F^-、Na^+、K^+离子为主,Ca^2+,SO4^2-含量较低,特征离子比值暗示流体来源于岩浆流体。成矿流体总体上属于H2O-NaCl体系。氢氧同位素组成显示,成矿流体主要来源于岩浆水。沸腾作用是辉钼矿沉淀的主要机制。The Zhujiawa molybdenum deposit is one of the large-size deposits recently discovered in the middle part of northern margin of North China Platform. The research on this deposit is relatively insufficient. The deposit is similar to the Caosiyao molybdenum deposit in metallogenetic mechanism in that they are both controlled by hypabyssal-super-hypabyssal acidic rock from deep source. The characteristics of ore-forming fluid constitute the key problem in revealing the genesis of ore deposits. In this paper, eleven core samples of molybdenum mineralization were collected from No.ZK2-1 and No.ZK2-2 drill hole. The results show that the fluid inclusions can be divided into four types. They are liquid-rich phase inclusions, daughter-minerals three phase inclusions, gas-rich phase inclusions and CO2-bearing three phase inclusions. Among them, CO2-bearing three phase inclusions are less distributed, whereas the other three types of inclusions are common. Homogenization temperatures and salinities of daughter mineral-bearing three phase inclusions are the highest, at about 400℃ and 45% Na Cleqv respectively. Homogenization temperatures and salinities of liquid-rich phase inclusions are 277.43℃ and 20% Na Cleqv respectively. Homogenization temperatures and salinities of gas-rich phase inclusions and CO2-bearing three phase inclusions are 380℃ and 30℃, 6%NaCleqv and 2.04% NaCleqv respectively. The initial fluid has the characteristics of high temperature, high salinity and rich CO2, and the fluid inclusion has the characteristics of the porphyry mineralization system within the continent. The fluid inclusion composition of gas and liquid phase shows that ore-forming fluid mostly contains H2O, Cl^-, F^-, Na^+, K^+,and minor Ca^2+and SO4^2-. Diagnostic ion ratios indicate that ore-forming fluid was derived from magmatic fluid. The ore-forming fluid in general belongs to the H2O-NaCl system. Hydrogen and oxygen isotopic composition of the fluid inclusion in quartz indicates that the water in ore-forming fluid was deriv

关 键 词：流体包裹体 氢氧同位素 钼矿床 华北地台北缘中段 张家口 朱家洼 

分 类 号：P618.65[天文地球—矿床学]