Geology and origin of the Dongsheng uranium deposit in the Ordos basin, North China

The Dongsheng uranium deposit in the Ordos basin, Northern China occurs in fluvial sandstones in the Zhiluo Formation, Middle Jurassic. Geologic characteristics of the deposit such as depositional environments of host sandstones, the distribution of ore bodies, uranium minerals, the mineralization age etc. are described in this paper. A "Multi-stage Uranium Mineralization" model is proposed for uranium ore-formation of the deposit. The mineralization process can be divided into four main stages, namely the preconcentration during diagenesis, the interlayer infiltration mineralization during Late Jurassic to Paleocene time, the reconcentration in Miocene, and the last stage of ore preservation exerted by reducing fluids after Eocene time.