鄂尔多斯盆地镇原地区环河组下段铀镭平衡系数特征及其地质意义OA
Characteristics and Geological Significance of Uranium-radium Equilibrium Coefficient in the Lower Member of Huanhe Formation in Zhenyuan Area of Ordos Basin
铀镭平衡系数是衡量铀镭放射性平衡状态的重要参数,可以显著反映铀矿层中铀元素的迁移和富集特征,是γ测井解释及资源量修正的重要参数.文章以镇原地区环河组下段矿石铀镭样品为研究对象,计算单样品铀镭平衡系数,分析矿石铀镭平衡系数频谱曲线特征,探讨了铀镭平衡系数与矿石样品铀含量、埋深、矿石粒度、所处不同地球化学环境以及铀矿体不同赋存部位之间的关系、分析了铀镭平衡变化规律中的地质因素和意义.研究发现,环河组下段矿石样品铀镭平衡系数介于0.23～1.25之间,加权平均值为0.64,数据符合正态分布,铀镭呈明显偏铀状态,表明矿体遭受了氧化改造,发生了铀的运移,且系数变化范围较大,证明发生了多期铀成矿作用.矿石铀镭平衡系数与铀含量之间呈负相关关系;样品粒度越小,铀镭平衡系数越小;处于氧化还原过渡带偏还原带一侧的灰色矿石相较偏氧化带一侧的黄色、褐红色矿石铀镭平衡系数更小;环河组下段3个旋回矿层整体偏铀,铀元素的富集明显,铀成矿作用一直持续至今,氧化带前锋线位置为铀成矿有利区块,从铀镭平衡系数的垂向和横向规律发现矿液在深部运移和富集的趋势,以及地下水活动和地球化学环境,发现铀镭平衡系数变化受多种地质因素控制,系统研究铀镭平衡系数对指导找矿部署,理解矿床成因和演化历史具有重要意义.
Uranium-radium equilibrium coefficient is an important parameter to measure the uranium-radium radioactive equilibrium state,which significantly reflect the migration and enrichment characteristics of uranium elements in uranium ore layers,and also an important parameter for gamma logging interpretation and resource volume modification.In this paper,the uranium ore samples from the lower member of Huanhe formation in Zhenyuan area were collected and used to calculate the uranium-radium balance coefficient and analyze the frequency curve characteristics of uranium-radium equilibrium of ores.The relationship of uranium-radium balance coefficient to uranium content,burial depth,ore grain size,geochemical environment and location of ore body were discussed.The geological factors and significance affecting the uranium-radium balance were analyzed.The study shows that the uranium-radium balance coefficients of the ore samples in the lower member of the Huanhe formation are between 0.23 and 1.5,with a weighted average value of 0.64,which conform to the normal distribution but bias to uranium in the equilibrium,suggesting that ore body has experienced oxidization and uranium migration by multi-stage mineralization.The uranium-radium balance coefficient of the ore is negatively correlated to the uranium content but positively to grain size.The balance coefficient of gray ore in the transition zone of oxidation and reduction is less than that of the yellow and brownish red ore in the oxidation zone.Ore layers in the three sedimentary circle of the lower member of Huanhe formation are uranium bias in uranium-radium balance with obviously enriched uranium,and the uranium mineralization has been forming to present.The vertical and horizontal change pattern of uranium-radium balance coefficient can not only show the migration and enrichment trend of deep ore fluid,but also the activity of groundwater and geochemical environment,and also benefit the analysis of geological factors controlling the the change of uranium-radium balance coefficient.Therefore,systematic study of uranium-radium balance coefficient is of great significance in analyzing the the genetic and evolutionary history of the deposits and guiding the deployment of uranium prospecting.
李磊;王伟;武正乾;刘坤鹏;冯博;刘凯鹏
核工业二〇三研究所,陕西 西安 710086核工业二〇三研究所,陕西 西安 710086核工业二〇三研究所,陕西 西安 710086核工业二〇三研究所,陕西 西安 710086核工业二〇三研究所,陕西 西安 710086核工业二〇三研究所,陕西 西安 710086
天文与地球科学
铀镭平衡系数规律研究环河组下段镇原地区鄂尔多斯盆地
uranium radium equilibrium coefficientpattern researchlower member of Huanhe formationZhenyuan areaOrdos Basin
《铀矿地质》 2026 (2)
315-327,13
中国核工业地质局项目"鄂尔多斯盆地南部旬邑-盐池地区铀矿资源调查评价与勘查"(编号:2022-17)资助.
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