Geochemical and mineralogical controls on metal(loid) mobility in the oxide zone of the Prairie Creek Deposit, NWT

A significant discovery at the Prairie Creek Zn-Pb-Ag deposit within Nahanni National Park reveals that smithsonite and cerussite, primary metal carbonates in the oxidized zone, host substantial concentrations of trace elements like Pb, Cd, Cu, As, Sb, Hg, Ag, and Se. These minerals can retain up to 53% of Hg and 79% of Ag within their structure, posing potential environmental risks if released during mining operations. The study employed advanced microanalytical techniques, including electron microscopy, laser-ablation spectrometry, and synchrotron-based mapping, to characterize these mineralogical controls on metal(loid) mobility under mine waste conditions. Findings suggest that while near-neutral pH may initially retain trace elements in solids, long-term oxidation and dissolution could mobilize these contaminants, particularly in localized flow paths or acidified environments.

Stavinga, D., Jamieson, H., Layton-Matthews, D., Paradis, S., & Falck, H. (2017). Geochemical and mineralogical controls on metal(loid) mobility in the oxide zone of the Prairie Creek Deposit, NWT. Geochemistry: Exploration, Environment, Analysis, 17(1), 21–33. https://doi.org/10.1144/geochem2015-378