Petrological, mineralogical, carbonate C-O and sulfide S isotope study of the Bayinqinggeli sandstone-hosted uranium deposit in the northern Ordos Basin

作者：Xiaowen Hu, Ming‐Xing Ling, Jianbing Xu, Qing Gong, Xiaoyong Yang, Huaming Li, Chao Lü, Zhan Li, Longhui Wang, Zhiyong Jason Ren, Tao Guo, Yujie Hu, Gaofeng Du, Wei Xie, Yijun Feng · 发表于：Ore Geology Reviews · 年份：2024 · DOI：10.1016/j.oregeorev.2024.106334 · 被引用次数：10 · 研究领域：Radioactive element chemistry and processing、Geological and Geochemical Analysis、Hydrocarbon exploration and reservoir analysis

• The mineralizing fluids were primarily sourced from oxidized surface water. • Organic matter and Fe 2+ -bearing minerals served as the reducing agents for U. • Calcite cementation preserved a lot of primary U minerals. Many sandstone-hosted uranium deposits have been discovered in the northern Ordos Basin, including the Bayinqinggeli deposit, exhibiting tremendous potential for uranium exploration and prospecting. This region is characterized by complex fluid activities, yet unknowns or controversies still exist regarding the source and properties of the fluids and their influence on uranium mineralization. In this study, we employed optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), micro X-ray fluorescence (μ-XRF), C-O isotope of calcite, and in situ S isotope of pyrite, to investigate the genesis and evolution of the Bayinqinggeli deposit. Pyrite and calcite are closely associated with uranium minerals, and all exhibit distinct characteristics in rocks of varying grades. In high-grade mineralized rocks, ore-related pyrite, characterized by euhedral and colloidal forms, mainly predated uranium mineralization, evidenced by the extensive coffinite replacement. The mostly negative δ 34 S values with a broad range (−24.6 ‰ to 23.9 ‰; mean = −4.2 ‰) point to microbial sulfate reduction under restricted conditions. In low-grade and barren rocks, pyrite unrelated to mineralization, mainly as large granular or colloidal cement, shows generally positive δ 34 ...