松辽盆地开鲁坳陷西部四方台组铀成矿条件及找矿方向  

Conditions and prospecting direction of uranium metallization in Sifangtai For⁃mation in West of Kailu Depression,Songliao Basin

作　　者：佟术敏 封志兵[2] 张婷婷 宁君[1] 姜山[1] 杨文达[1] 柳东良 臧亚辉 TONG ShuMin;FENG ZhiBing;ZHANG TingTing;NING Jun;JIANG Shan;YANG WenDa;LIU DongLiang;ZANG YaHui(Geological Party No.243,CNNC,Chifeng 024006,Inner Mongolia,China;Key Laboratory of Nuclear Resources and Environment,Ministry of Education,East China Institute of Technology,Nanchang 330013,Jiangxi,China;Education Teaching Direction Center in Hongshan District of Chifeng City,Chifeng 024006,Inner Mongolia,China)

机构地区：[1]核工业二四三大队,内蒙古赤峰024006 [2]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [3]赤峰市红山区教育教学指导中心,内蒙古赤峰024006

出　　处：《矿床地质》2023年第6期1247-1265,共19页Mineral Deposits

基　　金：中国核工业地质局项目(编号:202212);核工业二四三大队自主科研项目联合资助。

摘　　要：开鲁坳陷位于松辽盆地西南部,通过系统地分析开鲁坳陷西部铀源、构造、岩性-岩相、砂体氧化-还原、水文地质和铀矿化特征,笔者认为区内四方台组具备砂岩型铀矿成矿的基本地质条件。经统计蚀源区和地层本身砂体铀含量,数据显示该区具备丰富的内外双重铀源。深部还原流体可沿主干断层直接进入四方台组,这些断层也为地下水排泄提供通道。四方台组发育冲积扇、辫状河沉积体系,泥-砂-泥结构稳定,具备良好的地下水补径-排和水中铀水文地质条件。文章从氧化带、砂体Th/U值变化规律、Fe2+/Fe3+值及有机碳含量分布特征等方面阐述其与铀成矿的关系。铀成矿主要受铀源、构造、岩性岩相及砂体氧化-还原等关键因素控制,各种成矿要素匹配良好,具备形成中型及以上砂岩型铀成矿潜力。Kailu depression is located in Southwest Songliao Basin.Based on the systematic analysis of uranium source,structure,lithology-lithofacies,sand body oxidation-reduction,hydrogeology and uranium mineralization characteristics in the western Kailu depression,the author believes that the Sifangtai Formation has the basic geological conditions for sandstone type uranium mineralization.The statistical analysis of uranium content in the erosion source area and the sand body of the Formation indicates that there are abundant internal and external dual uranium sources in the area.Deep reduction fluids can enter the Sifangtai Formation directly along the main faults,which also provide channels for groundwater discharge.The Sifangtai Formation has developed alluvial fan and braided river sedimentary system with stable mud-sand-mud structure,good groundwater recharge,diameter and drainage and hydrogeological conditions of uranium in water.In this paper,the relationship between oxidation zone,Th/U value of sand body,Fe2+/Fe3+value and organic carbon content distribution are discussed.Uranium mineralization is mainly controlled by key factors such as uranium source,structure,lithology&lithofacies and oxidation and reduction of sand body,etc.All metallogenic elements are well matched in the Sifangtai Formation of the West Kailu Depression,where there is mineralization potential for forming of medium-size and above sandstone-type uranium deposits.

关 键 词：砂岩型铀矿 成矿条件 找矿方向 成矿潜力 开鲁坳陷 

分 类 号：P619.14[天文地球—矿床学]