鄂尔多斯盆地东北部东胜铀矿床古层间氧化带精细解剖  

Detailed Investigation of the Paleo-Interlayer-Oxidation Zone of Dongsheng Uranium Deposit in Northeastern Ordos Basin

作　　者：苗爱生[1,2] 焦养泉[1,3,4] 常宝成[2] 吴立群[1] 荣辉[1] 刘正邦[2] 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]核工业208大队,内蒙古包头014010 [3]中国地质大学构造与油气资源教育部重点实验室,武汉430074 [4]中国地质大学生物地质与环境地质教育部重点实验室,武汉430074

出　　处：《地质科技情报》2010年第3期55-61,共7页Geological Science and Technology Information

基　　金：国家自然科学基金项目(40772072;40802023);国家重点基础研究发展计划项目(2003CB214603)

摘　　要：鄂尔多斯盆地东北部的东胜铀矿床是一个古砂岩型铀矿床。由于二次还原作用,古层间氧化带呈现为特殊的绿色或浅绿色。大量的钻探和精细解剖发现,研究区的古层间氧化带具有明显的分带性,完全氧化带主要发育于河道上游,还原带主要位于河道下游,过渡带位于二者之间。河道砂体中沉积韵律的迅速变化既可以控制区域性的古层间氧化带前锋线的发育部位,也可以导致古层间氧化带出现多卷头现象。铀矿体主要形成于古层间氧化带前锋线附近的过渡带中。但是,当完全氧化带中出现残留的、原始的灰色还原带时也可以出现铀矿化。研究认为,对古层间氧化带前锋线产出位置的不断修正,是扩大东胜铀矿床规模、预测富铀矿体产出部位的有效手段。而河道砂体沉积韵律或沉积微相发生明显变化、灰色砂岩与绿色砂岩接触、铀异常扩散晕发育等现象的出现,都是寻找富铀矿体的标志。Dongsheng uranium deposit is a paleo-sandstone-type uranium deposit in northeastern Ordos Basin.Because of second deoxidation,the paleo-interlayer-oxidation zone appears in special green or light-green.A large number of drilling data and detailed investigations reveal the obvious zonation of the paleo-interlayer-oxidation zone.The complete oxidation zone mainly develops in the upstream of channel,while the reduction zone is mostly located in downstream of channel with the transitional zone inbetween.The rapid change of sedimentary rhythm in channel sand can not only control the development position of territorial vanguard line of the paleo-interlayer-oxidation zone but also may lead to many fronts of the ore-roll of the paleo-interlayer-oxidation zone.The uranium ore body mainly develops in the transitional zone nearby the vanguard line of the paleo-interlayer-oxidation zone.However,when the residual-original grey reduction zone appears in the complete oxidation zone,the uranium mineralization can be formed.The gradual modification of the location of the vanguard line of the paleo-interlayer-oxidation zone is an effective means to enlarge the scale of Dongsheng uranium deposit and predict the development location of rich uranium ore body.The parts of significant change of sedimentary rhythm or sedimentary facies in channel sand body,the parts of the contact between gray sandstones and green sandstones,the parts of diffuse halo of uranium anomalies are all the criteria for the prospecting of the rich uranium ore body.

关 键 词：古层间氧化带 东胜铀矿床 鄂尔多斯盆地 

分 类 号：P619.14[天文地球—矿床学]