贵州务川涪洋地区萤石矿床稀土元素地球化学特征  

Geochemical characteristics of rare earth elements of samples in some fluorite deposits in the Fuyang area,Wuchuan,Guizhou,China

作　　者：陈登 刘志臣 汤子程[1] 郭宇 张晓东 钟月丽 CHEN Deng;LIU Zhi-chen;TANG Zi-cheng;GUO Yu;ZHANG Xiao-dong;ZHONG Yue-li(102 Geological Brigade of Guizhou Bureau of Geology and Mineral Resources,Zunyi Guizhou 563000,China;Engineering Technology Innovation Center of Mineral Resources Exploration in Bedrock Area,Ministry of Natural Resources,Guiyang 550009,China;College of Resources and Environment,Guizhou University,Guiyang 550008,China)

机构地区：[1]贵州省地矿局一0二地质大队,贵州遵义563000 [2]自然资源部基岩区矿产资源勘查工程技术创新中心,贵州贵阳550009 [3]贵州大学资源与环境工程学院,贵州贵阳550008

出　　处：《矿物学报》2023年第6期861-872,共12页Acta Mineralogica Sinica

基　　金：贵州省找矿突破战略行动重大协同创新项目(编号:黔科合战略找矿[2022]ZD004);贵州省地矿局(编号:黔地矿科合[2020]2)。

摘　　要：贵州务川-沿河地区分布大量萤石矿床(点),这些矿床(点)多与重晶石矿共生,萤石矿赋存在奥陶系桐梓组和红花园组碳酸盐岩内,矿体分布严格受地层与北西向张性断裂控制。本文选择务川涪洋地区双河、鹿坪、一碗水和通木水等萤石矿床开展稀土元素地球化学研究,结果显示,各矿床萤石稀土元素配分模式均为右倾的轻稀土富集型,且具有一定的相似性。∑REE含量分别为28.96×10^(-6)~115.12×10^(-6)、123.10×10^(-6)~124.11×10^(-6)、14.77×10^(-6)~22.35×10^(-6)和20.73×10^(-6)~123.69×10^(-6),总体具有较强的Eu正异常、Ce负异常,表明这类萤石矿形成于较为氧化环境中。区内萤石属于北西向张性断裂和下奥陶统地层碳酸盐岩控制的中-低温热液充填交代型矿床。结合La/Ho-Y/Ho图解及矿床地质特征,本研究认为区内萤石为同一来源的成矿流体在同一成矿期次不同阶段成矿,其中双河矿床经历了多个阶段成矿叠加形成了中型规模萤石矿,鹿坪为成矿早期形成的萤石重晶石矿床,一碗水矿床为成矿晚期形成的紫色萤石矿。此外,通木水萤石矿与双河矿床有较为相似的地质地球化学特征,暗示类似的成矿环境和较大的找矿潜力。A large number of fluorite deposits(mineral occurrences)are distributed in the Wuchuan-Yanhe area of Guizhou Province.Most of them are associated with barite deposits.They occurred in carbonate rocks of the Ordovician Tongzi and Honghuayuan formations,and the distribution of their orebodies is strictly controlled by the strata and the NW-trending tensile faults.In this paper,the geochemical study of rare earth elements(REE)of samples from some fluorite deposits such as the Shuanghe,Luping,Yiwanshui and Tongmushui deposits in the Fuyang area of Wuchuan County has been carried out.The results show that the REE distribution patterns of samples from fluorite deposits are all right-declined LREE-enriched ones,with theirΣREE contents ranging from 28.96×10^(-6) to 115.12×10^(-6),from 123.10×10^(-6) to 124.11×10^(-6),from 14.77×10^(-6) to 22.35×10^(-6) and from 20.73×10^(-6) to 123.69×10^(-6),respectively.In general,they have relatively strong positive Eu anomalies and negative Ce anomalies,indicating that these fluorite deposits were formed in a relatively oxidized environment.The fluorite deposits in the area belong to a medium-low temperature hydrothermal filling metasomatism type deposit controlled by the NW-trending tensile fault and the carbonate rocks of the Lower Ordovician strata.Combined with the La/HO-Y/Ho diagrams and geological characteristics of those deposits,it is concluded that those fluorites were formed by the same sourced ore-forming fluid at different stages o f t he s ame ore-forming period.Especially,the Shuanghe deposit,a medium-scale fluorite deposit,was formed through the metallogenic superposition of three ore-forming stages.The Luping deposit is a fluorite-barite deposit formed in the early ore-forming stage,and the Yiwanshui deposit is a purple fluorite deposit formed in the late ore-forming stage.In addition,the Tongmushui and Shuanghe deposits have relatively similar geological and geochemical characteristics,suggesting that they have similar metallogenic environment and relatively

关 键 词：萤石矿 务川 稀土元素 地球化学 重晶石 

分 类 号：P595[天文地球—地球化学]