沉积特征对砂岩型铀成矿类型的制约——以松辽盆地南部姚家组为例

Constrain of sedimentary characteristics on the mineralization type of sandstone hosted uranium deposits——A case study of Yaojia Formation in the southern Songliao Basin

不同沉积体系砂体的特征不同,在后生铀成矿过程中所起的作用也不同。通过对松辽盆地南部姚家组地层沉积特征的研究,提出沉积特征对铀成矿类型有制约作用;上白垩统姚家组沉积体系以冲积平原、辫状河、三角洲和湖泊等为主,形成了稳定的泥-砂-泥地层结构,受沉积体系的控制,该区砂体厚度稳定、分布范围广,是松辽盆地南部寻找层间氧化带型铀矿的找矿有利目的层。

Sand bodies of different sedimentary systems have different lithologic characteristics and play different roles in the formation of epigenetic uranium ore mineralization. Sedimentary features of Yaojia Formation in the southern Songliao Basin are studied and,it is found that the sedimentary systems of Upper Cretaceous Yaojia Formation are mainly predominated by alluvial plain,braided river,delta and lake etc.,which forms a steady mud-sand-mud strata structure. Controlled by sedimentary systems,the sand bodies are characterized by steady thickness,large distribution. Therefore,Yaojia Formation in the southern Songliao Basin is the favorite sequence for prospecting inter-layered oxidation zone uranium deposits.