USING RE-OS AND SM-ND ISOTOPES TO DETERMINE THE AGE AND PROVENANCE OF THE PALEOPROTEROZOIC HURONIAN SUPERGROUP

The Paleoproterozoic may have been a critical time for the evolution of complex life, in part because the Huronian glacial events and the Great Oxidation Event would have fundamentally changed the nature of surficial chemical weathering and thus the flux of nutrients to the oceans. The relative timing of these events and of the oxygen proxy record through this interval is of great interest, yet age constraints are sparse. In this study, we used the Re-Os geochronometer to determine the depositional age of the Gowganda Formation of the Huronian Supergroup, Ontario. This age can be used to correlate with other glacial deposits to infer the global extent of this glaciation. In addition, we determined Sm-Nd isotope compositions of sediments from the Huronian Supergroup to evaluate the shifting sedimentary provenance, which has implications for Paleoproterozoic tectonic models and changes in weathering.