Experimental and theoretical studies of trace species in Earth materials, from mantle geodynamics to environmental applications and mineral exploration

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Trace species, such as substitutional or interstitial ions/molecules, vacancies and radiation-induced defects representing incipient radiation damage, in minerals and other Earth materials (e.g., melts and fluids) exert profound impacts on physical properties such as color, density, rheology, stability, electrical and thermal conductivity, magnetism, seismic velocity and many more. Trace species in Earth materials also have wide applications in solid and environmental Earth sciences from geochemical modeling to radiation dosimetry, geochronology, remediation of heavy metal/metalloid contamination, nuclear waste disposal and mineral exploration. The long-term objective of this research program is directed towards quantitative and mechanistic understanding of trace species in Earth materials, with emphasis on their geometric and electronic structures, physical properties, and applications. Scientific approaches include field-based investigations to identify specific trace species important to geological processes or directly relevant to environmental and technological applications. Laboratory experiments are designed to complement field-based research and to provide synthetic materials for spectroscopic studies that are often impossible for natural samples. Trace species in selected minerals and melts are characterized by use of multiple state-of-the-art analytical techniques, such as electron paramagnetic resonance, infrared, Raman, nuclear magnetic resonance and synchrotron X-ray absorption spectroscopy as well as periodic first-principles calculations and first-principles molecular dynamics simulations. Specific objectives for the next funding cycle are: 1) nature of radiation-induced defects in quartz and other silica with applications to mineral exploration, 2) effects of trace species in calcium carbonate minerals and carbonatitic melts from surface to lower-mantle conditions with relevance to environmental applications and mantle geodynamics, and 3) bromine systematics in rock-forming minerals and silicate melts with applications to magmatic-hydrothermal ore deposits. This research program on mechanistic understanding of trace species in Earth materials is unique in Canada and is innovative in exploring the frontiers of both experiments and theories. Also, this research program provides an excellent opportunity for highly qualified personnel (HQP) training in a multidisciplinary environment. The multidisciplinary nature of this research program is demonstrated by the attraction of high-quality HQP with diverse academic backgrounds from chemistry to engineering, geology, geophysics, materials science and physics, in-depth collaborations with chemists, materials scientists and physicists, and our publications in not only Earth science journals but also those in chemistry, materials science and physics.