Grant: Discovery Grants Program - Individual

My research focuses on deciphering the mechanisms and processes by which metals and metalloids migrate from buried mineralization to the surface through thick cover. This work is important because most near surface mineral deposits have been discovered; exploration needs to extend to greater depth. Furthermore, these metal migration processes also have significant in understanding human and ecosystem health. Currently, my research team includes 3 PDF, 2 PhD, 7 MSc and 2 BSc students (some co-supervised). This team will increase with the 2 PhD, 3 MSc and 5 BSc students included in this proposal. My team's work has revealed that metals can migrate through thick cover via different mechanisms based on the climate, seismicity and groundwater composition. Although we have been able to add much to the understanding of metal migration through thick cover, a number of theoretical and practical questions remain unanswered, including 1) the importance of ionic and electrochemical transport, including the role of microbes; 2) how metals and metalloids are sequestered in surface; and 3) how thick cover influences exploration techniques and mitigation of water and soil contamination. The key to answering these questions and understanding element migration processes requires a multidisciplinary approach (geochemistry, geology, microbiology, and soil science) that operates from the nano- and micron-scale (laser ablation, SEM, TEM) to the scale of an ore deposit. To address these questions I propose research using two field sites; the Martiniere deposit (Ontario) is a mixed Au and base metal deposit with thick till cover and the Sisson W-Mo deposit is dominated by metalloids (i.e., W, Mo, Tl). Field techniques (in situ pH, Eh, redox sensitive species) and samples (i.e., soil, till, groundwater) will be augmented by laboratory experiments (column, redox, and adsorption) to determine and quantify vertical migration of metals through till. We will investigate in detail where metals are being sequestered and what happens under variable conditions of water-rock-soil interaction in different geological media. Another key aspect of this research will be to use traditional and non-traditional isotopic techniques (e.g., Pb, Se, Cu, Fe) to quantify redox processes and better fingerprint metal sources. This project will involve developing sampling protocols to preserve the speciation of these metalloids as they migrate away from the ore deposit source and undergo changes in redox and water chemistry. This research will lead to new understanding of metal versus metalloid speciation and migration, refinement of models for migration of metals through thick cover, and novel approaches to understanding geochemical baselines. The proposal will result in the training of HQP at the PhD, MSc and BSc level in state-of-the-art analytical methods, geochemical modeling and field protocols.