Abstract:
Based on a systematic analysis of uranium source conditions, tectonic features, ore-hosting target layer characteristics, hydrogeological and paleoclimate conditions, drilling verification, and uranium mineralization features in the Liangjing area of the Southern Songliao Basin, it is inferred that the Sifangtai Formation (K
2s) possesses the fundamental geological conditions necessary for sandstone-type uranium mineralization in this region. The area is characterized by abundant uranium sources and a gentle slope structure trending NE-SW, with higher elevations in the east and lower elevations in the west. Oil-source faults penetrate the T
2-T
03 formations, facilitating fluid migration. A braided river sedimentary system is well-developed, featuring multiple sand bodies with good continuity and stability. These sand bodies exhibit high hydrocarbon content and significant reductive capacity. Stable mudstone-sandstone-mudstone sequences are present, along with a well-developed groundwater system characterized by a complete recharge-discharge-drainage mechanism. A weakly alkaline, oxidizing paleoclimate with alternating dry-heat and temperate-humid conditions promotes the activation and migration of uranium and other elements. This environment favors the formation of oxygenated uranium-bearing groundwater and the superposition of epigenetic oxidation processes, which enhance uranium mineralization. Uranium anomalies are predominantly developed in the middle to lower members of the K
2s Formation, with clear mineralization information and drilling verification results. The study suggests prioritizing exploration targets in the following areas: the sand-clay interbedding interface between distributary channel and inter-channel microfacies in the lower-middle section of the Sifangtai Formation, as well as zones of rock geochemical parameter anomalies. These features collectively represent optimal targets for identifying sandstone-type uranium mineralization in the Liangjing area.