Research Article
Origin and Role of Kaolinization in Roll-Front Uranium Deposits and Its Response to Ore-Forming Fluids in the Yili Basin, China
Table 1
Altered minerals and geochemical indexes of each geochemical zone in the Mengqiguer uranium deposit.
| Altered minerals and geochemical indexes | Oxidation zone | Transition zone (mineralized zone) | Primary zone | Strong oxidation zone | Weak oxidation zone |
| Colors | Red, light-red | Yellow, yellowish-white | Gray, grayish-white | Gray, dark-gray | Fe-minerals | Hematite, limonite | Limonite, rare pyrite | Pyrite, goethite | Pyrite, magnetite and siderite | Alterations | Hematitization, limonitization, kaolinization | Kaolinization, silicification, and uranium mineralization | Carbonation and chlorite | U-content (ppm) | 4.0–6.0 | 6.5–20.6 | >100 | 6.0–10.0 | Total organic carbon (TOC) (wt%) | 0.05–0.07 | 0.08–0.10 | >0.5 | >0.20 | Fe3+/Fe2+ | >0.9 | 0.5–0.8 | 0.3–0.5 | 0.2–0.4 |
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