山西灵丘县刁泉银铜矿流体包裹体特征及成矿流体演化  

Characteristics of fluid inclusions and fluid evolution of the Diaoquan AgCu deposit,Lingqiu County,Shanxi Province,North China

作　　者：牛斯达 李胜荣[1] 张聚全[1,2] 王志华 

机构地区：[1]地质过程与矿产资源国家重点实验室中国地质大学地球科学与资源学院,北京100083 [2]石家庄经济学院宝石与材料工艺学院,石家庄050031 [3]西安地质调查中心,西安710054

出　　处：《岩石学报》2014年第11期3432-3442,共11页Acta Petrologica Sinica

基　　金：国家自然科学基金重大研究计划重点支持项目(90914002)资助

摘　　要：刁泉银铜矿位于华北克拉通中北部,燕山造山带与太行山造山带的交切部位,为一矽卡岩型银铜矿,其成矿作用从早到晚划分为矽卡岩期、石英-硫化物期、碳酸盐期3个成矿期,并可进一步划分为5个成矿阶段。本文对石榴子石矽卡岩,含石英脉花岗岩、蚀变斑状花岗岩、黑云母石英二长岩等岩石以及矿石中的石榴子石、石英、方解石开展了详细的流体包裹体特征观察、测温及激光拉曼光谱研究。该矿床流体包裹体类型丰富,主要类型有富气相包裹体、富液相包裹体和含子晶包裹体。石榴子石和石英中的流体由高温高盐度流体和较低温中低盐度流体两种组分构成,方解石中主要为低温低盐度流体。石英流体气液两相包裹体均一温度峰值出现于200~220℃区间。石榴子石中不同类型包裹体有近似的均一温度（380~420℃）,表明矽卡岩期流体的沸腾及其在矿液沉淀和矿质卸载上的重要性。该矿床流体包裹体的盐度（%Na Cleqv）整体变化范围很大,介于0.2%~64.0%,从早期到晚期均一温度和盐度均呈下降趋势。石榴子石中流体包裹体密度分布于两个区间,而其在石英中的密度分布范围较广,在方解石中的密度分布则最为集中。估算矽卡岩期流体包裹体最低捕获压力为23~66MPa,按照静岩压力计算对应的流体深度为0.9~2.6km;石英-硫化物期5~46MPa,按照静水压力计算的流体深度为0.5~4.6km,Mo矿化主要发生在1~3km,而Cu-Ag矿化主要发生在0.5~1.5km。刁泉银铜矿为一与浅成低温热液有关的矽卡岩型矿床。Diaoquan deposit is a skarn Ag-Cu deposit,located in the north and central part of the North China Craton and the combination of Taihang Mountain orogenic belt and Yanshan orogenic belt. The mineralizations of this deposit can be divided into 3periods,including skarn,quartz-sulphide and carbonate period,and can be further divided into 5 stages. The characteristics,homogenization temperatures and laser Raman spectra of the fluid inclusions in garnet,quartz and calcite are studied in this paper.These inclusions are hosted in garnet skarn,granite containing quartz veins,altered porphyritic granite and biotite quartz monzonite.Types of fluid inclusions in the deposit are various,among which the main types are vapor-rich inclusions,liquid-rich inclusions and inclusions containing daughter minerals. Fluids in garnet and quartz are composed by two components,one with low temperature and salinity and the other with relatively higher temperature and salinity,while those in calcite only show the features of low temperature and salinity. Homogenization temperatures of two-phase fluid inclusions in quartz peak at 200 ~ 220℃. Approximate homogenization temperatures（ 380 ~ 420℃） of different types of inclusions in quartz indicate the boiling of fluid,which is of great importance in precipitation and unloading of the metal elements. The distribution of salinity（ % Na Cleqv） of the deposit is wide,ranging from 0. 2%to 64. 0%,showing a downward trend in both temperature and salinity from the early to late period. The distribution of density in garnet emerges in two intervals. That in quartz is wider,while in calcite the most concentrated. It is estimated that the minimum trapping pressure of fluid inclusions of this deposit in skarn period is 23 ~ 66 MPa. Computational fluid depth is 0. 9 ~ 2. 6km in accordance with the corresponding lithostatic pressure. Pressure of quartz-sulfide period is 5 ~ 46 MPa,and the calculated depth according to the hydrostatic pressure of the fluid is 0. 5 ~ 4. 6km. Mo mineralization occur

关 键 词：刁泉银铜矿 矽卡岩 流体包裹体 流体演化 华北克拉通中北部 

分 类 号：P618.41[天文地球—矿床学] P618.52[天文地球—地质学]