Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier (2017-2018 à 2019-2020).

The goal of this research is to characterize different types of Fe oxides present in unconformity-related U settings, and identify those closely associated with U mineralization. Iron is an abundant chemical component in the structure of rock-forming minerals. In U-rich settings, Fe and U oxides co-precipitate and/or U will be adsorbed on the surface of Fe oxides, and then will gradually be incorporated into the Fe Oxides structure that results in deposition of U. Fe oxides are stable over a wide range of oxygen fugacity. This stability enables them to preserve their trace element compositions inherited from formation environments. Dispersion of U-rich Fe oxides from weathered and eroded host rocks by different geologic agents such as glaciers and/or rivers can form a characteristics dispersal halos around U deposits. Detecting these halos can guide exploration geologists to undiscovered U deposits. As Fe oxides are not limited to a specific mineral deposit type or lithology, to use them as indicators for U exploration, this research proposes to characterize Fe oxides in targeted U-rich settings, and then use physical, chemical, and isotopic signatures of those closely associated with U mineralization for classification of the source of Fe oxide grains in unconsolidated sediments. To establish criteria for using Fe oxides in exploration for U deposits, this study proposes 1) collecting samples from a representative number of known Canadian U deposits such as Cigar Lake in the Athabasca Basin, their bedrocks, and barren lithologies surrounding these deposits as background; 2) characterizing color, grain size, textures, mineral associations, trace element compositions, and Fe and O isotope geochemistry of Fe oxides in collected samples using state of the art analytical techniques such as scanning electron microscopy (SEM), mineral liberation analysis (MLA), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS); 3) data integration, and data analysis using multivariate statistical techniques to construct discrimination models identifying Fe oxides indicating U mineralization; and 4) establish criteria for using Fe oxides in exploration for U deposits.x000D
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