四川米易海塔地区晶质铀矿稀土元素地球化学特征及其成因意义  

Geochemical Characteristics of Rare Earth Elements and Genetic Significance of Uraninite in Haita Area of Miyi,Sichuan Province

作　　者：陈友良[1] 张宝玲 尹明辉 姚建 顾孟娟 詹国鑫 范伟 CHEN Youliang;ZHANG Baoling;YIN Minghui;YAO Jian;GU Mengjuan;ZHANGuoxin;FAN Wei(College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Mianyang Teachers College,Mianyang,Sichuan 621000,China;Reaserch Institute No.280,CNNC,Guanghan,Sichuan 618300,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]绵阳师范学院,四川绵阳621000 [3]核工业二八O研究所,四川广汉618300

出　　处：《世界核地质科学》2022年第4期637-645,共9页World Nuclear Geoscience

基　　金：国家自然科学基金“康滇地轴中南段新元古代钠长岩型铀矿成矿机理研究”(编号:42072096);中国核工业地质局重点科研项目“康滇地轴铀成矿环境及选区研究”(编号:202137-3);成都理工大学珠峰科技计划(编号:2021ZF11413)联合资助。

摘　　要：Th和REE含量的高低是晶质铀矿的重要标型特征,稀土元素含量及其配分模式可以指示铀矿物的成因。文章采用LA-ICP-MS微区分析方法对四川米易海塔地区的粗粒晶质铀矿进行了稀土元素和铀、钍含量地球化学特征研究,结果表明:海塔地区的晶质铀矿可分为两组,第一组具有较高的ΣREE,均值为11 959.91×10-6,第二组ΣREE含量较低,均值为4 519.42×10-6,两组晶质铀矿均具有明显的负Eu异常和正Ce异常,U/Th比值介于5.01~17.97。综合分析表明,粗粒晶质铀矿形成于高温环境(>450±50℃),其形成可能与区内混合岩化过程中的部分熔融作用密切相关,两组具有相对不同稀土配分曲线的粗粒晶质铀矿可能是混合岩化作用不同阶段的产物。Th and REE contents are important typomorphic characteristics of uraninite,the content of REE and their distribution patterns can indicate the origin of uranium minerals.In this paper,the geochemical characteristics of rare earth elements,uranium and thorium contents in coarse-grained uraninite in Haita area of Miyi,Sichuan Province were studied by LA-ICP-MS analysis method.The results showed that rare earth elements characteristics of uraninite in Haita area can be divided into two groups.The first group had highΣREE(mean,11 959.91×10-6),while the second group had lowΣREE(mean,4 519.42×10-6).There are obvious negative Eu anomaly and positive Ce anomaly in both groups,and the U/Th ratio ranges from 5.01 to 17.97.The comprehensive analysis showed that coarse-grained uraninite was formed in high temperature environment(>450±50℃),and its formation may be closely related to partial melting in the process of migmatization in the area.The two groups of coarse-grained uraninite with relatively different REE partition curves may be the products of different stages of migmatization.

关 键 词：晶质铀矿 稀土元素 地球化学 成因意义 海塔地区 

分 类 号：P619.14[天文地球—矿床学] P595[天文地球—地质学]