摘要
云英岩型锂矿作为近年来新的锂矿类型,具有重要的理论研究和经济价值。然而,在中国南岭及其周缘世界级的钨锡成矿省中,伴生云英岩型锂矿化的综合评价却稍显不足。本课题组在赣南岩背斑岩锡矿田新发现了云英岩型的锂矿,矿体产于密坑山岩体与上覆鸡笼嶂组火山岩的接触带附近的云英岩带内,发育三种矿化类型:云英岩带型和花岗岩、火山岩内的含锂云母-石英脉型。矿体中Li_(2)O的含量最高可达1.04%,主要集中于0.2%~0.3%,具有显著的综合利用价值。为了确定云英岩型锂矿中Li的赋存状态及Li、Sn之间的关系等特征,本文开展了详细的镜下观察,扫描电镜、电子探针和LA-ICP-MS分析,确定了岩背矿田不同于国内外其他典型云英岩型锂矿床大量发育锂云母-铁锂云母系列,其Li载体矿物主要为黑鳞云母,具有高Si、Al、K、Fe、Li的特征,且未经历极端的流体分异演化过程。Li的成矿主要与矿区含斑细粒花岗岩有关,在岩浆晚期高温热液阶段与Sn共同富集,并以Si^(4+)+Li^(+)←→Al^(Ⅳ)+Fe^(T)耦合类质同象形式进入云母。
Greisen-type Li ore,a new type of lithium ore in recent years,is of great theoretical research and economic value.However,there is slightly insufficient in comprehensive evaluation of greisen-type Li ore in such a world-class Nanling W-Sn metallogenic province and its surroundings.In this work,we found greisen-type Li mineralization firstly in the Yanbei Sn-ore field,Huichang district,Jiangxi Province.The lithium mineralization occurred at the greisen belt near the contact zone between the Minkengshan granitic batholith and overlying volcanic rock of the Jilongzhang Formation.Three types of mineralization were identified:the greisen type,the quartz vein type in granite,and the quartz vein type in volcanic rock.The content of Li_(2)O reaches 1.04% and mainly ranges from 0.2%-0.3%,which is of significant comprehensive utilization value.The occurrence state of lithium and the metallogenic characteristics based on the detailed microscopic observation,scanning electron microscope(SEM)images,electron probe microanalysis(EPMA)and laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)is determined here.There is a potential difference between the Yanbei ore field and other domestic and international typical greisen-type lithium deposits,which develop lepidolite-ferrolepidolite series.The main Libearing mineral is protolithionite in the Yanbei ore field,and it is identified as high Si,Al,K,Fe and Li with no significant extreme fluid differentiation process.The Li,co-accumulated with Sn in the post-magmatic hightemperature gas-liquid stage,can be linked to the porphyritic fine-grained granite and enter mica via coupling substitution of Si^(4+)+Li^(+)←→Al^(Ⅳ)+Fe^(T).
作者
秦锦华
刘善宝
郭志强
王成辉
张树德
钟先源
QIN Jinhua;LIU Shanbao;GUO Zhiqiang;WANG Chenghui;ZHANG Shude;ZHONG Xianyuan(Key Laboratory of Metallogeny and Mineral Assessment,Ministry of Natural Resources/Institute of Mineral Resource,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Chongyi Zhangyuan Investment Holding Co.,Ltd.,Chongyi 341300,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2024年第4期546-557,共12页
Rock and Mineral Analysis
基金
国家重点研发计划项目课题“南岭钨锡多金属矿集区三维综合探测与深部成矿预测”(2022YFC2905101)
中国地质调查局地质调查项目“中国矿产地质志”(DD20221684,DD20190379)
中国地质科学院基本业务费项目“江西会昌淘锡坝—岩背矿田多期成锡机制研究”(KK2218)。
关键词
斑岩锡矿田
锂
黑鳞云母
扫描电镜
电子探针
云英岩
赋存状态
porphyry tin ore field
Li
protolithionite
scanning electron microscope
electron probe microanalyzer
greisen
occurrence state
