钱家店铀矿床(钱Ⅳ块)层间氧化带分布特征与铀矿化关系

Interlayer oxidation zone distribution pattern and uranium mineralization of Qianjiadian uranium deposit(QianⅣ)in Songliao Basin

通过对钻孔岩心观察、数据统计以及地质剖面对比分析,认为松辽盆地钱家店铀矿床(钱Ⅳ块)形成与层间氧化带、姚家组辫状河砂体还原介质发育等密切相关。该矿床层间氧化带控矿明显,存在红色后生氧化和黄色后生氧化,工业铀矿体均产于氧化还原过渡带内,综合考虑铀矿体与铀矿化体整体形态,铀矿化受层间氧化带控制呈现“卷状”特征产出,铀矿化在剖面上主要定位于红色氧化带减薄或尖灭部位,平面上主要分布于层间氧化带前锋线附近。铀的富集作用与原生还原介质有机碳的吸附作用及黄铁矿发育、 S^(2-)含量等有密切关系。微观上,铀吸附于炭化植物碎屑的植物空腔内,并且局部与黄铁矿共生,U含量与S^(2-)含量呈正相关性。

Based on logging and cross section analysis,it is considered that the formation of Qianjiadian uranium deposit in Songliao Basin is closely related to the interlayer oxidation zone,lithogeochemistry environment,braided river sandstone in Yaojia Formation,the content of reduction medium and structures.The interlayer oxidation zone controlled the uranium mineralization.There are red and yellow epigenetic oxidation.The industrial uranium mineralization conducted in the transition zone.The uranium mineralization is roll front type due to the development of interlayered oxidation zone.On section view,the uranium mineralization usually developed in the place of where the red oxidation zone reduced or disappeared.On the plane surface,the uranium mineralization usually developed in the area near the red oxidation front line.Moreover,uranium accumulation is closely related to the content of organic carbon,pyrite,and S^(2-).Uranium adsorbed and precipitated in charring plant remnants.Uranium and pyrite are intergrowth relationship.Uranium content is positive correlation with the content of S^(2-)in sandstone.