Frost Action during the Younger Dryas Inferred from Soil Micromorphology at Connley Cave 5, Oregon

The Younger Dryas chronozone is an abrupt climate event terminating the last glacial period similar to 12,900-11,700 calendar years ago marked by rapid changes in regional human, floral, and faunal population dynamics across the globe. Working at Connley Cave 5 in the Fort Rock Basin, Oregon, we demonstrate that this cold event generated microscopic cryogenic features (frost action) which can be used to identify the presence of the Younger Dryas in the northern Great Basin, shed light on paleoenvironmental conditions, and inform archaeologists about site formation processes occurring across the Late Pleistocene to Early Holocene transition. These data inform us about cryoturbation at Connley Caves and have implications for Younger Dryas-aged archaeological sites preserved throughout the Great Basin.