Kalin T. McDannell , C. Brenhin Keller , Robert H. Rainbird, Keith Dewing, Jeremy W. Powell, Paul B. O'Sullivan

It has long been speculated that isolated Paleoproterozoic basins of northern Laurentia are remnants of a once contiguous sedimentary cover due to similarities in stratigraphy, paleocurrent directions, sediment provenance, and geochronological data. However, corroborating evidence for this 'superbasin hypothesis' has been lacking outside the footprints of the preserved basins. We present new zircon and apatite (U-Th)/He and fission-track thermochronology data and time-temperature inversions from metamorphic basement that support the previous existence of sedimentary cover over currently exposed shield regions, bridging the gap between preserved basin strata across a large expanse of northern Canada. Inversions also reveal a notably synchronous and relatively rapid cooling event consistent with deep erosional exhumation during supercontinent breakup and Snowball Earth glaciations. Our study provides a comprehensive dataset from the exposed craton in northern Canada that supports an originally more widespread Proterozoic basin and offers additional evidence of ~4.3 ± 1.1 km of Neoproterozoic erosional exhumation that played a role in the formation of the Great Unconformity surface across North America.