甘肃北山南部总口子盆地砂岩型铀矿成矿条件及找矿潜力分析

Analysis on Metallogenic Conditions and Prospecting Potential of Sandstone-type Uranium Deposit in Zongkouzi Basin,Southern Beishan,Gansu Province

总口子盆地基底形态总体特征是两凹夹一隆,东部凹陷对砂岩型铀成矿最为有利,下白垩统下沟组是该区找矿目标层位,沉积类型以扇三角洲平原亚相为主。通过对构造演化、沉积建造、铀源和氧化还原蚀变特征等进行研究,结合最新钻探成果,分析总口子盆地砂岩型铀矿的成矿条件及找矿潜力,认为该区红柳大泉凹陷具有较平稳的构造环境、丰富的铀源条件、有利的扇三角洲平原亚相。找矿目的层经历了古气候的多次频繁转化,发育一套灰、绿灰、暗灰色砂岩、粉砂岩、泥岩夹砂砾岩,夹煤层、煤线、油页岩,动植物化石丰富,具备良好的还原条件。经钻探查证,在总口子盆地首次发现了工业铀矿孔,指示了该区砂岩型铀成矿条件良好。

The general characteristics of the basement morphology of the Zongkouzi basin are two depressions and one uplift.The eastern depression is the most favorable for sandstone-type uranium mineralization.The lower Cretaceous Xiagou Formation is the target horizon for prospecting in this area,and the sedimentary type is mainly fan delta plain subfacies.Based on the research on structural evolution,sedimentary formation,uranium source and redox alteration characteristics,combined with the latest drilling results,this paper analyzes the metallogenic conditions and prospecting potential of sandstone-type uranium deposits in the Zongkouzi basin.It has a relatively stable tectonic environment,rich uranium source conditions,and favorable fan delta plain subfacies.The ore prospecting target layer has undergone many frequent transformations of paleoclimate,and developed a set of gray,green gray,dark gray sandstone,siltstone,mudstone intercalated with glutenite,intercalated coal seam,coal line,oil shale,which is rich in animal and plant fossils,with good recovery conditions.Through drilling and verification,industrial uranium ore holes were discovered in the Zongkouzi basin for the first time,indicating that the sandstone-type uranium metallogenic conditions in this area are good.