铜仁坝黄磷矿稀土元素地球化学特征及其指示意义  

REE Geochemistry Characteristics and Indication Significance of the Bahuang Phosphorite Deposit in Tongren,Guizhou

作　　者：杨旭[1] 谢宏[1] 王志罡 周忠容 Yang Xu;Xie Hong;Wang Zhigang;Zhou Zhongrong(College of Resource and Environmental Engineering,Guizhou University,Guiyang 550025,China;Guizhou Geological Proepecting Institute of China Chemical Geology and Mine Bureau,Guiyang 550003,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]中化地质矿山总局贵州地质勘查院,贵州贵阳550003

出　　处：《中国稀土学报》2018年第6期760-768,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(41662008);贵州省科技计划项目(黔科合平台人才[2017]5788);贵州大学引进人才科研项目(贵大人基合字[2015]37)资助

摘　　要：贵州铜仁坝黄磷矿富含稀土元素,且伴生Ni,Mo,V,U等有益元素。采用电感耦合等离子体-质谱仪(ICP-MS)对研究区含磷岩系稀土元素含量进行了测试分析。结果表明:磷块岩稀土总量较高,高于下伏老堡组硅质岩及近矿围岩,并富集重稀土元素Y,ΣREE与P_2O_5成正相关关系,推测稀土元素可能赋存于碳氟磷灰石中;磷块岩稀土配分曲线略左倾,具有明显Ce的负异常,LREE/HREE较低,Eu具弱负异常至弱正异常,此外在REE-La/Yb关系图上,磷块岩落于沉积岩-玄武岩-花岗岩交汇区域,表明磷块岩具热水沉积特征;剖面上Ce异常及ΣREE的变化特征,揭示磷块岩形成于较深水的陆缘海环境,且在新元古代末到早寒武世,坝黄矿区经历过一次明显的海侵-海退过程;磷块岩Ceanom均小于-0. 1,沉积速率低于近矿炭质页岩及下伏硅质岩,说明坝黄磷块岩形成于相对氧化且沉积速率低的环境。Bahuang phosphorite deposit is enriched in rare earth element and associate with nickel,molybdenum, vanadium,uranium and other beneficial elements.The REE contents of phosphorus rock series in this area are analyzed by ICP-MS method.The results of analysis suggested that the total REE concentrations of phosphorites are higher than the basal Laobao formation silicalite and wall rock,and the Y element is enriched.∑REE is positively correlated with P2O5,which presumed that rare earth elements may exist in the carbonate-fluorapatite.The rare earth distribution curves of phosphorites are slightly leftward,with a negative Ce anomaly,low LREE/HREE, weakly negative Eu anomaly and positive anomaly.In addition,phosphorites falls in the sedimentary rock,basalt and granite areas of the REE-La/Yb diagram,indicating that phosphorites have the characteristics of hydrothermal sedimentation;And the variation of Ce anomaly and ∑REE in the section showed that phosphorites are formed in the epicontinental sea of the deep water,and the Bahuang ore district experienced a marine transgression and regression in the Neoproterozoic to the early Cambrian.Phosphorites Ce are all less than -0.1,and the deposi- tion rate is lower than that of near-mine carbonaceous shale and the basal silicalite,shows that phosphorites are formed in the environment with relatively oxidation conditions and low deposition rate.

关 键 词：稀土元素 地球化学特征 沉积指示意义 磷块岩 铜仁 坝黄 

分 类 号：P595[天文地球—地球化学]