贵州戈塘金矿萤石微量元素特征及钐—钕测年  

Trace Element Characteristics of Fluorite and Its Sm-Nd Isotopic Dating in Getang Gold Deposit,Guizhou Province

作　　者：黄建国[1,2] 李虎杰[1] 李文杰[1] 董磊[1] 

机构地区：[1]西南科技大学环境与资源学院,四川绵阳621010 [2]贵州大学资源与环境工程学院,贵州贵阳550003

出　　处：《地球科学进展》2012年第10期1087-1093,共7页Advances in Earth Science

基　　金：全国危机矿山接替资源找矿项目"西南地区层控型多金属矿床成矿规律总结"(编号:20089943)资助

摘　　要：对与戈塘金矿共生的萤石微量元素特征研究表明:萤石中Mo,W,As,Cd,Bi等高温元素含量均高于地壳值,V,Cr,Cu,Cs,Th,Mo,Ga和Ge等元素变异系数大,活化能力强。萤石的稀土总量很低,仅为10.299×10-6～17.455×10-6,明显富集重稀土(LREE/HREE为0.48～0.69),并具有Eu和Ce的负异常(δEu为0.71～0.91,δCe为0.62～0.78),Tb/Ca-Tb/La图解显示萤石为热液成因且为热液的晚期阶段。萤石的Rb/Sr比值和初始87Sr/86Sr比值均与地幔值较为接近,反映出其成矿流体主要来源于上地幔或(岩浆)深部。萤石的形成经历了长期演化的热液活动,成矿温度较低(<200°～250°),成矿年龄为(35.83±0.37)Ma(Sm-Nd等时线年龄)。Trace element characteristics of symbiotic fluorite with Getang gold deposit have shown that： Its high-temperature element（including Mo,W,As,Cd,Bi,etc.） have higher contents than the crustal values.Those elements（including V,Cr,Cu,Cs,Th,Mo,Ga,Ge,etc.） have bigger coefficient of variation and strong activation energy.Fluorite＇s total REE is low,only 10.299×10-6-17.455×10-6,and enrichment of heavy rare earth is obvious（LREE/HREE is 0.48-0.69）,and have negative anomalies of Eu and Ce（δEu=0.71-0.91,δCe=0.62-0.78）.The Tb/Ca vs.Tb/La diagram shows that fluorite is hydrothermal and is in its late stage.Rb/Sr ratios of fluorite and its initial 87Sr/86Sr ratios are closer to the mantle value,which reflect that its ore-forming fluids are from the upper mantle or（magma） deep.The formation of fluorite experienced a long-term evolution of the hydrothermal activity,lower ore-forming temperature（200°-250°）,and mineralization age is 35.83±0.37 Ma（Sm-Nd isochron age）.

关 键 词：戈塘金矿 脉石矿物 萤石 微量元素 SM-ND年龄 

分 类 号：P619.215[天文地球—矿床学]