松辽盆地南部姚家组沉积特征及铀成矿条件

Sedimentary features and uranium metallogenic conditions of Yaojia formation in southern Songliao basin

松辽盆地是我国东北地区大型的含油气产铀盆地,其盖层中的上白垩统姚家组在盆地南部广泛分布,埋深适中;沉积体系以冲积平原、辫状河、三角洲、湖泊等为主,具有稳定的泥-砂-泥地层结构;砂体厚度稳定,分布范围广,有机质和铀含量高;沉积期的温热-半温热古气候有利于富铀建造的形成。姚家组补-径-排水动力体系完善,后生改造条件较佳。综合分析结果显示,该组具有较好的铀成矿潜力,是松辽盆地南部找铀矿的主攻目的层位。

Songliao basin,NE China,is a large basin containing oil-gas and uranium ore.The upper cretaceous Yiaojia formation is widely distributed at the south part of Songliao basin.It is moderately buried and its sedimentary system consist mainly of fluvial plain,braided river,delta and lacustrine.It has stable mud-sandstone-mud sequence structure and stable thickness of sandbodies.It has high content of organic matter,reduce capacity and uranium.The humid to semi-humid paleoclimate in the sedimentation epoch of Yaojia formation was favorite for the formation of uranium rich strata.Yaojia formation has perfect hydrodynamic system of recharge-run off-discharge and it has good conditons of epigenic reworking and alteration.Comprehensive analysis shows that it has good petential for uranium metallization.It is the key targe layer in southern Songliao basin.