Extensive Frost Weathering Across Unglaciated North America During the Last Glacial Maximum

In unglaciated terrain, the imprint of past glacial periods is difficult to discern. The topographic signature periglacial processes, such as solifluction lobes, may be erased or hidden by time and vegetation, thus their import diminished. Belowground, weathering, particularly frost cracking, have imparted a profound influence on weathering erosion rates during climate regimes. By combining mechanical frost-weathering model with full suite Last Glacial Maximum simulations, we elucidate meters-deep magnitude continent-spanning expanse across North America at ∼21 ka. surprising extent modeled suggests, proxy, broad legacy diverse processes. Complementing previous studies that championed role precipitation-driven changes in Critical Zone evolution, our results imply an additional strong temperature control surficial process efficacy much modern America, both climes.