陕西省双王金矿床成矿流体特征及其地质意义  

Characteristics and Geological Significance of Fluid Inclusions in the Shuangwang Gold Deposit,Shaanxi Province

作　　者：刘必政[1] 王建平[1] 王可新[1] 刘家军[1] 谢海鹰[1] 曹瑞荣 惠德峰 程建军 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]陕西太白黄金矿业有限责任公司,陕西太白716000

出　　处：《现代地质》2011年第6期1088-1098,共11页Geoscience

基　　金：国家自然科学基金项目(41030423);中国黄金集团公司科技项目"陕西省太白县双王金矿床地质特征;成矿规律及找矿靶区再研究"

摘　　要：双王金矿位于陕西省太白县西南部,矿床赋存于秦岭泥盆系地层中。双王金矿床8号、9号、7号、5号、6号、2号矿体内热液矿物流体包裹体系统研究表明:成矿早期、主成矿期和成矿后期包裹体均一温度主要范围分别为300～463℃、220～340℃和100～279℃。主成矿期成矿流体具有低盐度(2.1%～22.7%NaCleqv)、富CO2和含有N2、CH4等气体的特征。从矿区东部向西部成矿压力有逐渐降低的趋势,流体体系趋于开放。成矿流体来源较为复杂,以岩浆水和变质水为主,后期有大气降水的混入。包裹体的多样性及演化特征和角砾岩型矿化特征显示双王金矿床成矿流体具有不混溶性特征,成矿压力约为100～170 MPa。流体的减压沸腾是导致金沉淀成矿的重要原因。The Shuangwang gold deposit is located in the southwest of Taibai County,Shaanxi Province.It occurred in the Devonian strata of the Qinling orogenic belt.Systematic fluid inclusion study of hydrothermal minerals from No.8,7,9,5,6 and 2 ore bodies shows that the inclusions of the Shangwang gold deposit had diversity of characteristics.The range of homogenization temperature of inclusions in early ore-forming stage,main ore-forming stage and late ore-forming stage are from 300 to 463 ℃,220 to 340 ℃,and 100 to 279 ℃ respectively.The characteristics of main ore-forming stage fluid are low salinity content（2.1%-22.7% NaCl eqv）,rich in CO2 and containing N2,CH4 and other gases.From east to west,the trapping pressure is gradually decreasing,and the open fluid system tends to be dominant.Mineralizing fluids were mixed fluids which mainly originated from magmatic and metamorphic water.At the later stage,some meteoric water joined into the fluid system.The diversity and evolution of fluid inclusions and a large number of breccia ores indicate that ore-forming fluids of the Shuangwang gold deposit have the characteristics of fluid unmixing,the metallogenic pressure is from 100 to 170 MPa.Boiling caused by decreasing of fluid pressure is the most important reason of gold deposition.

关 键 词：双王金矿床 成矿流体 流体包裹体 流体不混溶性 

分 类 号：P618.51[天文地球—矿床学]