Pleistocene Glaciations in Central Utah – A Review

Abstract Several mountain ranges in central Utah were glaciated during middle and late Pleistocene time. The Wasatch and Fish Lake Plateaus supported significant areas of cirque and valley glaciers during the last glacial maximum (LGM, ~21 ± 2 ka). Evidence for an older glaciation on the Fish Lake Plateau is unambiguous, but a consensus has not been reached regarding the presence of pre-LGM glacial deposits on the Wasatch Plateau. The Pahvant Range, Sevier Plateau, and Tushar Mountains all supported smaller areas of glacier ice during the LGM. Evidence for an older glaciation is present on the Sevier Plateau and possibly in the Tushar Mountains. Reconstructions of equilibrium line altitudes (ELAs) of paleo-glaciers suggest that the average temperatures during the LGM in central Utah were between 4 and 14°C colder than present. The proximity of some central Utah mountain ranges to Pleistocene Lake Bonneville may have enhanced or even facilitated glaciations due to “lake-enhanced” snowfall lowering local ELAs. Further dating and paleo-glacier reconstructions are needed to fully understand the paleoclimatic significance of central Utah glacial advances and to more directly test hypotheses regarding possible lake-enhanced snowfall from Pleistocene Lake Bonneville.