Petrogeochemical characteristics of Nalinggou uranium deposit, Ordos basin

Nalinggou uranium deposit is one of the newly discovered in situ leachable sandstone type uranium deposits in China. The orebody is of platy shape which is localized in sandbody of braided river in Zhiluo formation of middle Jurassic and controlled by paleo-interlayer oxidation zone. The petrogeo- chemical characteristics of uranium ore and surrounding rocks shows that the ore host sandstone is low in composition maturity and it is closely related to organic matter. The hosting rocks is of higher content of FeO, Al₂O₃, CaO, Na₂O and lower content of Fe₂O₃, Mgo than that of the ore. The reason for this difference is the combination of reducing alteration. The content of Se. Mo, V in uranium ore increased with uranium content and Re content is linearly associated with U content. The relations between Sc content and uranium content are not significant. Characteristics of trace and rare elements in sandstone from Zhiluo formation seems crustal granite (S-type granite), which indicated that uranium rich granite from ancient Yinshan land was an significant material source for lower Zhiluo formation deposition in this area, and was also important uranium source for later uranium mineralization. (authors)