CHARACTERISTICS OF SAND BODY AND URANIUM MOTALLOGENIC POTENTIAL IN SIFANGTAI FORMATION OF YI'AN SAG, NORTHERN SONGLIAO BASIN

Based on the results of drilling and sampling analysis, the paper summarizes the characteristics of sedimentary facies, sand body development and epigenetic alteration of Upper Cretaceous Sifangtai Formation in Yi'an sag, northern Songliao Basin. The Sifangtai Formation can be divided into upper and lower members, with developed braided river facies sediments and meandering river facies sediments respectively. There are usually 1-2 layers of sand body developed in braided river facies, large in scale, with epigenetic oxidation locally. Through the analysis of uranium source, structure, sand body development and epigenetic transformation characteristics, it is considered that Sifangtai Formation has good conditions necessary for sandstone-type uranium mineralization, with great uranium prospecting potential.