摘要
芨岭铀矿床是解析龙首山成矿带铀成矿作用的关键所在.通过地质编录、镜下观察、电子探针和地球化学特征研究,综合矿床与周边铀矿点的蚀变和地球化学特征,将热液作用分为成矿前、成矿早期、主成矿、后成矿和成矿后等5个阶段.自矿体中心向外(A→F)的6个蚀变带中Na2O、U含量递减,SiO2和Rb含量呈宽缓的"U"型,FeO和MgO在A和E带中形成双峰,而P2O5和HREE则在A和D带含量较高,TiO2、Fe2O3、CaO、MnO、CO2、Zr、V、Cs、REE等组分主要富集于B、C和D带.成矿流体是起源于岩浆演化晚期的再平衡岩浆水,富含Na+、U6+、CO32-.逆向沸腾是主要的成矿机制,pH和Eh的变化进一步促进了沥青铀矿的沉淀.以蚀变组合分带与铀矿化关系为指导,有望在龙首山成矿带中段落实一个大型铀矿基地.
The Jiling Na-metasomatic uranium deposit is one of the most important deposits in the Longshou mountains ore belt,which is a key to the research on uranium mineralization in this area.Based on the logging data,microscope analysis,electronic probe and geochemical characteristics,we divide hydrothermal process into 5 stages including premetallogenic,early metallogenic,main metallogenic,post-metallogenic and after metallogenic stage.The alteration zones can be divided into zone A to zone F from the ore center to the alteration outer,and their geochemical characteristics are as follows:Na2O and U contents decreasing distinctly from zone A to zone F;SiO2 and Rb contents show a relieved"U"type;FeO and MgO contents show bimodal in zone A and zone E,while P2O5 and HREEs contents are relatively higher in zone A and Zone D;TiO2,Fe2O3,CaO,MnO,CO2,Zr,V,Cs and REEs contents are distinctly higher in zones B,C and D.The ore forming hydrothermal solution is rebalanced magma water,which is rich in Na+,U6+and CO32-.Pitchblende was downloaded from hydrothermal solution by fluid boiling for pressure releasing suddenly,and the changing of pH and Eh promoted the conversion from U6+to U4+.It could be hoped for a large scale uranium base are to be found under the guidance of altered mineral assemblages diagram in deep prospecting and ore forecasting.
作者
赵如意
陈毓川
陈云杰
荣骁
王刚
李涛
Zhao Ruyi;Chen Yuchuan;Chen Yunjie;Rong Xiao;Wang Gang;Li Tao(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013 China;Key Laboratory of Metallogeny and Mineral Resource Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;The No.203 Research Institute of Nuclear Industry,Xianyang 712000,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2020年第2期434-450,共17页
Earth Science
基金
中国核工业地质局项目(Nos.201349,201571)
中国地质调查局中国矿产地质与成矿规律综合集成和服务(矿产地质志)项目(No.DD20160346)
中国地质调查局项目(Nos.12120114014901,DD2016013622)
东华理工大学核资源与环境国家重点实验室自主基金项目(No.Z1914).
关键词
龙首山
芨岭
钠交代型铀矿
蚀变矿物组合
地球化学
含铀热液
资源潜力
Longshou mountains
Jiling
Na-metasomatic type uranium
alteration mineral assemblages
geochemistry
U-bearing hydrothermal
resource potential
作者简介
赵如意(1982—),男,工程师,博士后,主要从事矿产资源调查与评价工作,重点进行岩浆岩与成矿研究.ORCID:0000 0001 9877 0262.E mail:93236749@qq.com
