The Middle Proterozoic Record of Tectonic, Biogeochemical, and Eukaryotic Evolution

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Earth's middle age, ca. 1.8 to 0.8 billion years ago, witnessed the diversification of early eukaryotic and the gradual oxygenation of the environment that set the stage for the origin of animals. This billion-year interval was bracketed by the formation of two supercontinents whose assembly and break-up likely profoundly influenced ocean chemistry and the spatial and temporal distribution of sediment-hosted mineral deposits. Elucidating the patterns and linkages between tectonic, biogeochemical, and eukaryotic evolution during the middle Proterozoic Era is a grand scientific challenge that is made possible by the extensive and well-preserved middle Proterozoic sedimentary record in northern Canada. In the next five years, I will lead an interdisciplinary effort to document and calibrate the middle Proterozoic record of paleoenvironmental change and test the interconnections and feedbacks between the evolving biosphere, ocean oxygenation, and plate tectonics. This research program will be grounded in fieldwork in northern Canada and focused on understanding and parsing the sedimentary successions in which these records are archived. Hence, this research will entail field seasons devoted to stratigraphic and sedimentological analysis of Proterozoic sedimentary basins to better constrain their age, tectonic context, and geological history. This fieldwork will also serve to collect appropriate high quality samples for diverse analyses and approaches to interrogating the sedimentary record, including radiometric dating, isotope geochemistry, micropaleontology, and paleomagnetism. Analytical work will be performed by my highly skilled and diverse research group and by colleagues with complementary, specialized research expertise. Providing HQP with the opportunity to train in cutting edge analytical methods will be prioritized. Resulting data will serve both to document the evolution of the middle Proterozoic environment and to develop and test mechanistic models for what drove these changes. At the same time, these data will inform stratigraphic correlations and interpretations of depositional environments. Samples collected over the course of this research program will be carefully catalogued and made available for other research projects. This research program will improve the stratigraphic framework for Proterozoic basins in Arctic Canada, the origin of which will be linked with emerging models for the tectonic evolution of Proterozoic North America. Data from these basins will in turn be integrated with datasets from other middle Proterozoic basins in order to better calibrate and construct the middle Proterozoic geological time scale. These results will both inform the economic potential of these basins and shed new light on the global paleoenvironment that was the cradle of early complex life.