Critical Minerals Geology and Exploration

Mineralogy and Chemistry of V-bearing shales at the Van Property, Mackenzie Mountains, Northwest Territories

Online pre-recorded
(Student abstract)


T.A.P. Green (Presenting)
Department of Earth Sciences, University of Manitoba
S.M. Brueckner
Department of Earth Sciences, University of Manitoba
M.A. Reynolds
Northwest Territories Geological Survey, GNWT

Vanadium (V) is a critical metal with important applications in green technologies and steel production, but is underexplored globally and within Canada. Among the different types of V deposits, those hosted in black shale have so far attracted little attention despite their upside potential. This is partly because of the poor understanding of their genetic processes and mineralogy. Vanadium in the Van Property of the Mackenzie Mountains, Northwest Territories, is hosted in shales with up to 1.6 wt% V2O5 (measured by portable XRF). Vanadium mineralization occurs in the Lower Cherty Mudstone Member of the Duo Lake Formation (Road River Group), which was deposited in the Selwyn Basin during the Ordovician to Silurian. This project is designed to investigate the V mineralogy and whole rock lithogeochemistry of a suite of V-rich samples from the property.

Preliminary petrographic observations of hand samples and light and scanning electron microscopy of thin sections show very fine-grained, thinly bedded mudstone with varying graphite content, locally cross-cut by calcite veins. In addition to these methods, samples have been submitted for whole-rock lithogeochemical analysis to determine the composition of the shales including trace element concentrations, total carbon and sulphur, graphite, and organic carbon content. Based on the available literature, we anticipate results to show a positive correlation between V and organic matter content. Additionally, V-bearing minerals are expected to be silicates rather than oxides due to the reducing nature of the host rock. Anticipated future work will include electron probe microanalysis and hydrocarbon speciation to determine the V-bearing minerals, presence and speciation of organic matter, and their correlation.