Palaeogeomorphologic features in the critical period of uranium mineralization in Binxian area, southern Ordos Basin

During Middle Jurassic period, i.e., the sedimentary period of Lower Zhiluo Formation, the braided channel was a favor-able sand body of uranium reservoir that hosted uranium, and uranium was mainly controlled by palaeogeomorphology and mainly developed in low-lying areas. The Late Jurassic, Early Cretaceous-Paleocene and Eocene-Miocene were main uranium mineralization stages. Palaeogeomorphology controlled the migration of underground water, the distribution of the redox zone and the enrich-ment of uranium deposits. During the Late Jurassic uranium pre-mineralization period, diving leaching caused the migration of uranium-bearing materials from the uplift to the slope and low-lying areas; during the main uranium mineralization period of Early Cretaceous-Paleocene, palaeogeomorphology controlled the direction of the water flow with oxygen and uranium, and the redox zone was distributed mainly in the slope area of the ancient landform.