【作者】 刘正邦； 苗爱生； 焦养泉； 吴立群； 丁叶； 刘洁梨；

【Author】 LIU Zheng-bang;MIAO Ai-sheng;JIAO Yang-quan;WU Li-qun;DING Ye;LIU Jie-li;Beijing Research Institute of Chemical Engineering and Meteallurgy,CNNC;Geologic Party No.208,CNNC;University of Geosciences;Institute of Western Drilling Logging Company;

【机构】 核工业化工冶金研究院； 核工业二O八大队； 中国地质大学； 西部钻探测井公司研究所；

【摘要】 鄂尔多斯盆地东胜铀矿床的成因已经引起广泛关注,准确认识该矿床成因,对该区下一步勘探部署具有重要的意义。本文通过密集钻孔控制和详细沉积学编图等手段,对东胜铀矿床东段进行了精细解剖发现,该矿床的古层间氧化带产出于直罗组下段下亚段中,铀矿化作用受控于适当规模的辫状河道-辫状分流河道砂体,富矿体主要产于与绿色砂岩相邻的灰色砂岩中。在此基础上,结合地质背景和室内地球化学测试分析,对该矿段成因分析表明,该矿床的形成主要经历了4个阶段:含矿岩系沉积预富集阶段、古层间氧化作用成矿阶段、后期层间氧化改造阶段与晚期还原作用保矿阶段。其中在古层间氧化作用成矿阶段,还原介质的含量对铀成矿作用以及矿体特征具有重要影响;在后期层间氧化改造阶段,受新构造运动的影响,东胜铀矿床东部铀矿体遭受改造、叠加富集作用;在晚期还原作用保矿阶段,还原气体(烃类)沿断裂或砂体内部孔隙运移增强了赋矿载体的还原能力,使矿体形态呈似层状、板状,卷状矿体。更多还原

【Abstract】 The genesis of Dongsheng uranium deposit in the Ordos basin has attracted widespread attention,and accurate understanding of the genesis has the vital significance for the further exploration.Based on intensive drilling and detailed sedimentology mapping,the east sect of Dongsheng uranium deposit was depicted,the paleo-interlayer-oxidation zone of the deposit formed in lower submember in lower member of Zhiluo Formation,it was controlled by braided channel and braided distributary channel sand,the rich ore body mainly formed in the grey sandstone adjacent to green sandstone.On this basis,combining geological background and indoor geochemical test,four stages were mainly experienced of the deposit:ore pre-enrichment stage,the paleo-interlayer-oxidation metallogenic stage,interlayer oxidation reduction stage and reductive protecting ore of late stage.During the paleo-interlayer-oxidation metallogenic stage,the content of reduction medium had an important influence on uranium mineralization and orebody characteristics.In the interlayer oxidation reduction stage,the uranium ore body of the east sect of Dongsheng uranium deposit was reconstructed and enrichment superimposed.And in reductive protecting ore of late stage,the reductive gas(hydrocarbon) enhanced ore-hosting reductive ability which can moved through the fault and sandbodies pore,and the ore body were layer shape,board shape and roll shape.更多还原