Hyperspectral analysis at Angularli uranium deposit, Northern Territory

Abstract

Angularli is an unconformity-style uranium deposit with an inferred category Mineral Resource of 1.37 Mt at 1.09% U3O8 containing 32.9 Mlbs U3O8. Proterozoic unconformity-style uranium deposits in the Alligator Rivers Uranium Fields (ARUF) are located within structural traps at or adjacent to an unconformity between undeformed redbed sandstone and underlying metamorphosed crystalline basement rocks. At Angularli, high-grade uranium mineralisation is hosted within a steep, northeast-dipping, north-northwest striking fault zone (Angularli fault zone - 'AFZ'). Visual drill core logging by company exploration geologists identified silica-sericite-clay-pyrite alteration around the Angularli uranium mineralisation. Petrography, x-ray diffraction, geochemistry and metre-spaced spectral data complemented the core logging.

This study aims to determine whether there are mineralogical changes in lithologies at Angularli deposit that vary with distance from the uranium mineralisation. Interpretation of the observed mineralogy is in terms of the likely geological formation process, such as diagenesis, metamorphism, alteration or weathering. This report also contains detailed documentation of spectral parameters that are applicable for other hyperspectral studies. An additional aim of this study is to determine how to apply the results as exploration vectors for unconformity-related uranium mineralisation in the ARUF.