Geochronology of planetary and resource evolution

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The U-Pb age dating of microminerals such as zircon (ZrSiO4) has become the benchmark technique for calibrating the geologic time scale. The extremely slow volume diffusion properties of zircon, its resistance to chemical breakdown in tectonic and impact processes, its crystallization in a wide range of temperature, pressure and fluid environments, and its occurrence in resource deposits and early solar system materials make it an increasingly important tool for planetary science and resource geology. Processes previously inaccessible to geochronologists are now being quantified through pairing of age information from crystal zones with coincident measurements of stable isotope and trace element composition, and microstructure. Recent progress by Moser's group has laid the foundation for geochronology of high temperature deformation and fluid movement within tectonic plates. The proposed program is designed to develop these new geochronology methods using specialized electron beam techniques in Moser's newly established laboratory. These include multispectral Cathodoluminesence and Electron Backscatter Diffraction to reveal the micro- to nano-scale chemical and structural zoning in U-bearing microcrystals in relation to the host mineral assemblages. This critical material science data will be coupled with ion and laser beam analysis of targeted domains for radiogenic isotope, stable isotope and trace element analysis. This methodology will be applied by Moser's growing team of HQP in a range of earth and planetary science projects many of which involve partnership with the Canadian mineral and exploration industry or support economic development in the North. These include; Earth's oldest rocks and the diamond prospectivity of Arctic Canada, tracing impact melt sources in the mineralized Sudbury and Vredefort impact craters, the evolution of meteorite samples of the lunar crust, and the high precision dating of source strata for fossil fuels in Western Canada. A total of nine graduate students and five senior undergraduate students will be trained to measure ages and rates of planetary processes including those which generated the Canadian lithosphere and its resources.