Late proterozoic stratigraphy of the Yukon and its record of earth system evolution

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This proposal links with a concurrent Discovery proposal to pursue an interdisciplinary research program on the late Proterozoic (c. 1000-540 Ma) geological record of the Yukon. These rocks are exposed in a series of mountainous inliers extending through the north-central Yukon, from the Alaska border in the west to the border with the Northwest Territories in the east. The exceptionally preserved strata in this region record the tectonic evolution of ancestral North America spanning the break-up of the supercontinent Rodinia. Formerly contiguous sedimentary sequences occur on the margins of the continental fragments that rifted apart from northern and western Canada from about 850 to 550 million years ago. Together, these rocks bear witness to multiple glacial epochs, at least two of which were global in extent, and to a tumultuous transition to a fully oxygenated environment that supported the origin and diversification of animal life. The complex evolution of the Neoproterozoic Earth system reflects interconnetions between tectonics, global climate, the biosphere, and ocean chemistry. My research group will combine rigorous fieldwork in the Yukon with state-of-the-art geochemical techniques and innovative coupled climate-biogeochemical modeling to establish and interpret the 1) the timing and nature of northwestern North America's break-up from the supercontinent Rodinia, 2) the influence of rifting and associated magmatism on climate and marine geochemistry, and 3) the tempo of important biogeochemical and biospheric changes and their connections to other global events. The research will involve a team of McGill undergraduate and undergraduate students and a network of international collaborators. The outcomes will directly assist exploration for sediment-hosted Cu and Fe in northwestern Canada and possible links to mineralized belts on formerly adjacent continents.