Quantifying fertile alteration in the Patterson Lake corridor, Saskatchewan, through visible-near infrared-shortwave infrared spectroscopy

Abstract

Visible-near infrared - shortwave infrared (VNIR-SWIR) spectroscopy, gamma-ray logs, and magnetic susceptibility measurements were taken on drill core samples that span the Patterson Lake exploration corridor (PLC) on the south-western margin of the Athabasca Basin. Clay mineralogy and mineral properties (composition, crystallinity) derived from reflectance spectra were compared with gamma-ray and magnetic susceptibility profiles to assess relationships between uranium mineralization and alteration in the crystalline basement. In all drill core, the clay mineralogy is similar to the clay alteration in deposits of the eastern portion of basin, although in the PLC, dickite is uncommon and kaolinite horizons are associated with high-grade mineralization. Several drill core exhibit trends between spectral parameters related to the crystallinity and thermal maturity of clays (illite and kaolinite) and uranium mineralization. A non-mineralized drill core with moderate clay alteration was expectantly nonmagnetic. In comparison, the magnetic susceptibility within a mineralized hole that included multiple lithologies correlated with observed parameters computed from reflectance spectra. These results highlight the efficacy of VNIR-SWIR reflectance spectroscopy in characterizing clay alteration associated with uranium mineralization. As shown throughout the Athabasca Basin, mineralogy and spectral parameters may vector towards fertile fluid conduits when expanded to property- or corridor-scales.