砂岩型铀矿化铀系不平衡特征研究  

The Uranium Isotopic Disequilibrium Characteristics of Sandstone Type Uranium Mineralization

作　　者：刘汉彬[1] 夏毓亮[1] 林锦荣[1] 范光[1] 

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《地球学报》2005年第B09期134-139,共6页Acta Geoscientica Sinica

基　　金：本文为核工业地质局科研项目（编号：测DD-0202）资助.

摘　　要：在讨论砂岩型铀矿化铀系核素主要分离机制的基础上，研究了鄂尔多斯盆地、吐哈盆地和西胡里吐盆地不同类型砂岩型铀矿化不同分带的铀系核素不平衡特征，结果表明，含矿砂岩中^234U／^238U，^230Th／^238U的活度比在不同分带具有不同分布规律。鄂尔多斯盆地古潜水氧化转层间氧化带型铀矿化前锋处于慢速成矿作用体系，成矿环境及矿体的演化呈现相对稳定的状态；吐哈盆地层间氧化还原带型铀矿化前锋处于相对不稳定状态，在上新世以后成矿物质U仍具有迁移活动发生；西胡里吐盆地U系核素在空间上分布说明不同部位的砂体中U具有迁移和富集现象，为判断潜水氧化型铀矿化有利成矿地段提供了依据。Based on discussing main separation mechanisms of U series nuclides in sandstone type mineralization, this paper deals with the uranium series nuclides activity ratios of different sandstone type uranium mineralizations in Ordos basin, Turpan-Hami basin and Xihulitu basin. The analytical results suggest that ^234U/^238U, ^230Th/^238U ratios in ore-hosting sandstone deposits have different distribution regularities in different zones. The front of the mineralization in the transitional place between the relic phreatic water oxidation zone and the interlayer oxidation zone in Ordos basin is in a slow ore-forming system, and hence the ore-forming environment and the evolution of deposits are in a relatively stable condition. The front of the interlayer oxidation zone type mineralization in TurpanHami basin is in a relatively unstable condition, and the ore-forming material U still migrated after Pliocene. The spatial distribution of U series nuclides in Xihulitu basin shows that the uranium in different parts of ore-hosting sandstone has experienced migration and enrichment. All these results provide evidence for determining favorable places in search for sandstone type uranium deposits in the phreatic water oxidation zone.

关 键 词：盆地 砂岩型铀矿 地球化学分带 铀系不平衡 核素活度比值 砂岩型铀矿化 特征研究 鄂尔多斯盆地 ^238U 不稳定状态 

分 类 号：P619.14[天文地球—矿床学] P585.2[天文地球—地质学]