塔里木盆地中下侏罗统砂岩型铀矿成矿条件分析  

Metallogenic Conditions of Sandstone Type Uranium Deposits in the Middle and Lower Jurassic of Tarim Basin

作　　者：刘念 秦明宽[1] 郭强[1] 许强 肖菁 杨烨[1] 孙红林 LIU Nian;QIN Mingkuan;GUO Qiang;XU Qiang;XIAO Jing;YANG Ye;SUN Honglin(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China;School of Geology and Mining Engineering Xinjiang University,Urumqi,Xinjiang 830017,China)

机构地区：[1]核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室,北京100029 [2]新疆大学地质与矿业工程学院,新疆乌鲁木齐830017

出　　处：《铀矿地质》2022年第5期843-855,共13页Uranium Geology

基　　金：塔里木盆地核能开发项目(编号:地HTLM2101);中核集团第四批青年英才项目(编号:QNYC2102)联合资助。

摘　　要：塔里木盆地是我国最大的中新生代内陆沉积盆地,其中下侏罗统为重要的产铀层位。文章以塔里木盆地中下侏罗统为研究对象,从铀源、构造、建造以及油气还原和后生氧化条件等方面进行综合分析,并在此基础上,探讨了下一步找矿方向。结果表明,塔里木盆地的周缘山体具有优越的外部铀源条件,后期遭受持续性风化剥蚀淋滤,能够为盆地砂岩型铀成矿提供丰富的铀物质。中下侏罗统在盆地边缘的缓倾部位发育辫状河、辫状河三角洲沉积相,在靠盆地中心发育滨浅湖、半深湖沉积相,构成多套砂泥岩互层,是塔里木盆地砂岩型铀矿赋存的理想空间。塔里木盆地中下侏罗统底界埋深往往较大,可探空间集中在孔雀河斜坡,且白垩纪以来的持续性掀斜为砂岩型铀矿的富集成矿奠定了良好的构造条件;多期的油气逸散、含氧含铀水渗入以及后期构造活动的耦合,为中下侏罗统砂岩型铀矿提供了良好的油气还原和后生氧化条件。孔雀河斜坡西部和东部具有较浅的埋深、有利的沉积相带、后期持续缓慢的掀斜以及多期油气流体还原和后生氧化的特征,为塔里木盆地侏罗系砂岩型铀矿找矿的有利方向。This paper conducted a comprehensive analysis of uranium source,structure,sedimentary,oil and gas reduction and epigenetic oxidation conditions of the Middle and Lower Jurassic in the Tarim Basin.On this basis,the next prospecting direction was discussed,which provided a theoretical basis for the decision-making of sandstone-type uranium exploration in the Middle and Lower Jurassic.The results showed that the surrounding mountains of the Tarim Basin had superior external uranium source conditions and suffered continuous weathering and denudation leaching in the later stage,which provided rich uranium materials for the sandstone uranium mineralization in the basin.The braided river and braided river delta sedimentary facies were developed in the Middle and Lower Jurassic at the edge of the basin,and shore-shallow lake and marsh facies were developed near the center of the basin,resulted in the Multiple interbed sets of sand and mudstone,which is an ideal space for the formation of sandstone-type uranium deposits.The burial depths of the Middle and Lower Jurassic in Tarim Basin are usually large,therefore the exploration space was concentrated in Kongquehe slope,a continuous slanting area since the Cretaceous with good structural conditions.The coupling of multi-stage oil and gas migration,seepage and later structural activities provided good reduction conditions for the formation of sandstone-type uranium deposits in the Middle and Lower Jurassic.The west and east areas of the Kongquehe slope are characterized by shallow burial depth,favorable sedimentary facies,continuous slow tilting,and multi-stage hydrocarbon fluid reduction and epigenetic oxidation,which are favorable area for the prospecting of the Jurassic sandstone type uranium deposits in the Tarim Basin.

关 键 词：砂岩型铀矿 成矿条件 中下侏罗统 塔里木盆地 

分 类 号：P619.14[天文地球—矿床学]