柴达木盆地北缘英东地区铀矿物特征及成因分析  

Characteristics and genetic analysis of uranium minerals in the Yingdong area of the northwestern margin of Qaidam Basin

作　　者：陈擎 陈云杰 陈斌 邵恒博 张胜龙 李强 CHEN Qing;CHEN Yunjie;CHEN Bin;SHAO Hengbo;ZHANG Shenglong;LI Qiang(Research Institute No.203 of Nuclear Industry,Xi’an 710000,Shanxi,China)

机构地区：[1]核工业二〇三研究所,陕西西安710000

出　　处：《矿产勘查》2024年第5期745-755,共11页Mineral Exploration

基　　金：中国铀业有限公司-东华理工大学核资源与环境国家重点实验室联合基金(2022NRE-LH-17);中国核工业地质局项目(202219-1)联合资助。

摘　　要：英东铀矿点位于柴达木盆地柴西坳陷的英东地区,是近年来铀矿“新区、新类型、新层系”三新找矿中新发现的一个砂岩型铀矿点。铀矿化赋存于上新统上油砂山组的辫状河三角洲前缘相水下分流河道砂体中,受“层间氧化渗入+油气还原渗出”界面控制;矿石偏铀,铀矿物主要为铀石和钒钾铀矿,分布在石英、长石、角闪石、钛铁矿、黄铁矿、有机质及黏土矿物的边部和裂隙中;铀矿物中U^(6+)/U^(4+)比值为0.91,U^(4+)含量稍微偏高,表明其成矿环境偏还原;铀石是沥青铀矿经过后期油气还原蚀变作用形成的,钒钾铀矿是由早期形成的铀石被现代水氧化形成的,表明其成矿作用持续至今。The Yingdong Uranium Mine is located in Yingdong area of Chaixi Depression in Qaidam Basin,which is a sandstone-type uranium deposit newly discovered in the three new searches for uranium mines of"new area,new type and new layer system"in recent years.Uranium mineralization is hosted in the subaqueous distributary channel sands of the braided river delta front of the Upper Neogene Upper Oil Sands Hills Formation,and is controlled by the interface of"interlayer oxidative infiltration+hydrocarbon reductive seepage";The ore is uranium-biased and the uranium minerals are mainly uraninite and vanadium-potassium uraninite,which are found in the margins and fissures of quartz,feldspar,hornblende,ilmenite,pyrite,organic matter as well as clay miner-als;The U^(6+)/U^(4+)ratio in the uranium ore is 0.91,and the content of U4+is slightly high,indicating a reducing environment for mineralization;Uranite was formed from bituminous uranium ore by later hydrocarbon reduction alteration,and vanadium-potassium uranium ore was formed from early-formed uranium ore oxidized by modern water,suggesting that mineralization has continued to the present day.

关 键 词：铀矿物 成因分析 英东地区 柴达木盆地 

分 类 号：P627[天文地球—地质矿产勘探]