Relationship between provenance-deposition lobes and uranium mineralization: A case study from the northern Songliao basin

The uranium mineralization in the Sifangtai Formation of the northern Songliao Basin is widely distributed, and the complex origins of its uranium reservoir sand bodies pose significant constraints on uranium deposit prediction and exploration. The uranium mineralization in the Sifangtai Formation of the northern Songliao Basin is extensively distributed, with the complex origins of its uranium reservoir sand bodies posing severe constraints on uranium deposit prediction and exploration. This paper employs comprehensive research methods, including sandstone geochemistry, heavy mineral analysis, and detrital zircon UPb geochronology, to accurately trace the provenance of uranium reservoir sand bodies in the Sifangtai Formation of the northern Songliao Basin. The research results indicate that the average content of quartz, feldspar, and rock debris in the sandstone of the Sifangtai Formation is 42 %, 37 %, and 21 %, and the CIA is from 61.81 to 72.81 with an average of 68.56. The apatite-tourmaline index of heavy minerals (ATi) in the sandstone of the Sifangtai Formation are mostly greater than 50, the Garnet-Zircon index of heavy minerals (ZGi) is mostly less than 50, and the stable coefficient of heavy minerals (ZTR) ranges from 9.63 % to 35.78 %. The main peak value of detrital zircon is concentrated in the Jurassic-Permian, with ages ranging from 165 to 294 Ma, and the secondary peak is concentrated in the Cretaceous, with ages ranging from 92 to 148 Ma. This study indicates that the uranium reservoirs of the Sifangtai Formation are greywacke and feldspathic sandstone, with the parent rock originating from the upper crust and being the Permian-Jurassic and Early Cretaceous medium acidic magmatic rocks formed in the active continental margin. The western provenance of the Sifangtai Formation is provided by the Daxing'an Moutains, the northern provenance is supplied by the Xiaoxing'an Moutains, and the eastern provenance is offered by the Zhangguangcai Mountains. The source-to-sink system of the Sifangtai Formation has led to the formation of three provenance-deposition lobes in the west, north and east of the northern Songliao Basin, which control the development of the uranium reservoirs. The three provenance-deposition lobes show different uranium mineralization potential, in which the western provenance-deposition lobe has the highest metallogenic potential.