贵州水银洞金矿构造蚀变体稀土元素地球化学特征  

Geochemical Characteristics of REEs in Structure Alteration Rocks of the Shuiyingdong Gold Deposit,Guizhou Province

作　　者：杨成富[1] 刘建中[2] 陈睿[1] 王泽鹏[3] 闫宝文[3] 夏勇[3] 莫荣思[1] 

机构地区：[1]贵州大学资源与环境工程学院,贵阳550003 [2]贵州省地质矿产勘查开发局105地质大队,贵阳550018 [3]中国科学院地球化学研究所,贵阳550002

出　　处：《矿物岩石地球化学通报》2012年第4期404-413,共10页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：贵州大学研究生创新基金资助项目(校研理工2011014);贵州省地矿局重大科研项目[黔地矿科(2009)11号]

摘　　要：水银洞金矿构造蚀变体(SBT)为产出于茅口租(P2m)和龙潭组(P3l)之间不整合面上的一套强硅化灰岩、灰岩角砾岩、硅化粘土岩组合。采用ICP-MS测定钻孔岩芯中构造蚀变体样品稀土元素组成,对比研究SBT围岩、区域岩浆岩及现代海底热水系统流体稀土元素组成。结果显示,SBT的轻重稀土分馏明显[LREE/HREE=4.92～17.51,(La/Yb)N=5.94～38.37],曲线右倾型;轻稀土分异明显,曲线右倾程度大;重稀土分异不明显,曲线平坦;负Eu(0.61～0.94)、Ce(0.52～1.07)异常明显;SBT及围岩均具有明显W型稀土元素四分组效应,而不同于区域岩浆岩和现代海底热水系统流体,表明热液流体来源以壳源为主。The structural alteration rocks（named as SBT）,composed by heavily silicified limestones,silicified limestone breccias and silicified mudstones are altered from those rocks overlying the unconformity between Permian Maokou Formation and Longtan Formations in the Shuiyingdong gold deposit,southwest Guizhou Province,China.REEs concentrations in SBT samples from drill cores were analyzed by Inductively Coupled Plasma Mass Spectrometry（ICP-MS）.The result showed that REEs in SBT samples are characterized by enrichment of LREEs.LREE/HREE=4.92～17.51,（La/Yb） N =5.94～38.37,notable LREE fractionation with right-inclined REEs distribution patterns,negative Eu anomaly（δEu0.61～0.94） and Ce anomaly Ce（δCe 0.52～1.07）.These characteristics are very similar to those of their host rocks（tetrad effect of REE found in both SBT and host rocks）,and are quite distinct from those of igneous rocks near the Shuiyindong gold deposit and modern seafloor hydrothermal fluids.As a result,it is suggested that hydrothermal fluids in the Shuiyindong gold deposit may mainly derive from the crust.

关 键 词：构造蚀变体 稀土元素 四分组效应 水银洞金矿 

分 类 号：P618.51[天文地球—矿床学] P595[天文地球—地质学]