浙东南离子吸附型稀土矿床成矿规律与找矿方向探讨  

A discussion on the metallogenic regularity and prospecting direction of ion-absorption type rare earth deposits in southeastern Zhejiang Province

作　　者：陈晨 王成辉[1] 赵芝[1] 杨岳清[1] 樊锡银 党晓亮 张伟 CHEN Chen;WANG Chenghui;ZHAO Zhi;YANG Yueqing;FAN Xiyin;DANG Xiaoliang;ZHANG Wei(MNR Key Laboratory of Metallogeny and Mineral Assessment,Insititute of Mineral Resource,CAGS,Beijing,100037;The Seventh Geological Brigade of Zhejiang Province,Lishui,Zhejiang323000)

机构地区：[1]自然资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所,北京100037 [2]浙江省第七地质大队,浙江丽水323000

出　　处：《地质学报》2020年第1期270-286,共17页Acta Geologica Sinica

基　　金：中国地质调查局“中国矿产地质志”项目(编号DD20160346、DD20190379);“大宗急缺矿产和战略性新兴产业矿产”工程“华南重点矿集区稀有稀散和稀土矿产调查项目”(编号DD20160056);广东省大宝山英安斑岩中铜多金属矿物综合利用研究项目(编号HE1921)资助成果

摘　　要：离子吸附型稀土矿(以下简称iRee)主要分布于我国南岭地区,浙江省虽不在南岭五省之内,但经过浙江省地勘单位三十多年的不断探索,在浙东南地区陆续发现了数个稀土矿及多个成矿远景区,填补了浙江省该类型稀土矿的找矿空白。为探究浙东南iRee矿床地质特征、成矿影响因素以及稀土元素运移、赋存规律,圈定成矿远景区,本文对区内出露的花岗斑岩型iRee,火山岩型iRee以及变质岩型iRee进行系统采样,通过岩相学、岩石地球化学等方法对各类iRee剖面进行对比研究。分析结果表明,荷地花岗斑岩的平均∑REE为271.39×10^-6,凝灰岩围岩平均∑REE为253.36×10^-6,大柘片麻岩∑REE约为517.21×10^-6,而南岭含矿岩体的平均∑REE约为289×10^-6,表明浙东南地区iRee矿床具有较好的成矿母岩条件。此外,通过对原岩中各矿物稀土元素含量的测定,查明了稀土元素主要赋存在独立的稀土矿物及少量的副矿物中,是主要的成矿物质来源;通过风化壳剖面的对比,发现稀土元素地球化学特征主要继承原岩性质,而外生作用条件使得稀土元素发生次生富集。在此工作基础上,结合前人研究成果,初步总结了区内离子吸附型稀土矿矿床成矿规律,并讨论下一步找矿方向。In order to explore the geological characteristics,factors influencingore-formation,migration and occurrence of rare earth elements of iRee deposit in southeastern Zhejiang Province,and to delineate the ore-forming prospect area,this study systematically sampled the outcropped granite porphyry iRee,volcanic iRee and metamorphic iRee,and made a comparative study of various iRee profiles using petrography and rock geochemistry.The results show that the average∑REE of Hedi granite porphyry is 271.39×10^-6,the average∑REE of tuff is 253.36×10^-6,the average∑REE of Dazhe gneiss is 517.21×10^-6,and the average∑REE of Nanling ore-bearing rock is 289×10^-6,which indicates that iRee deposit in southeast Zhejiang Province have good ore-forming rock conditions.In addition,bydetermining the content of rare earth elements in the original rocks,it was found that the rare earth elements mainly exist in independent rare earth minerals and a small amount of accessory minerals which are the main source of ore-forming materials.By comparing the weathering crust profiles it was found that the geochemical characteristics of rare earth elements mainly retain the properties of the original rocks,while the exogenous conditions cause secondary enrichment of the rare earth elements.On the basis of this study,combined with the results of previous research work,this paper presents a preliminary summary of the metallogenic regularity of ion-adsorbed rare earth ore deposits in the area,and discussesfuture prospecting directions.

关 键 词：离子吸附型稀土矿 浙东南 成矿规律 

分 类 号：P618.7[天文地球—矿床学]