Nalinggou uranium deposit is located in the Yishan monoclinal structure area of the northeastern Ordos Basin. The upper part of the lower member of Zhiluo Formation of Middle Jurassic is the metallogenic rock. Through the field geological survey, core logging, and combining the methods of the rock-mineral determination, X-diffraction, electron probe, and scanning electron microscope, the characteristics of detrital grain composition, structure, mineral alteration were explained in detail. In the end, some questions about the provenance, tectonic background of source region, formation of green sandstone and the diagenesis were also discussed simply. The results showed that the types of uraniferous sandstone were mainly composed of feldspathic litharenite. Both compositional maturity and textural maturity were poor, the diagenesis was weak, and it exhibited the weak compaction, cementation, dissolution and partial recrystallization. A large number of the thin film shaped chlorites on the particles surface and the intergranular filled chlorites were the major cause why the sandstones displayed green tone. Besides, its provenance was likely to come from the Yinshan Mountains in northern margin of the basin, where developed the Archaean-Proterozoic metamorphic series and Phanerozoic magmatite. The study of alteration mineral assemblage showed that the sequence of mineral formation was the strawberry pyrite, authigenic kaolinite, clay film and intergranular chlorite, coffinite+colloidal pyrite, crystal calcite, calcite vein. And its diagenetic environment experienced respectively the weak reduction phase, acid reduction phase, weak acid/weak alkaline/redox transition phase, and alkaline reduction phase in the end. While uranium enrichment was closely related to the redox and acid-alkali transitional diagenetic environment.
Chen Lulu Li Jianguo Feng Xiaoxi Tang Chao He Jing Guo Hu Chen Yin Zhao Hualei Wang Gui. Petrology and mineralogical characteristics of the uranium-bearing purpose layer in the Nalinggou area of Ordos Basin and their instructions to diagenesis and provence[J]. Chinese Journal of Geology, 2019, 54(1): 225-243.