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

ABSTRACT

The Younger Dryas chronozone is an abrupt climate event terminating the last glacial period ∼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.

KEYWORDS:

• Younger Dryas
• geoarchaeology
• soil micromorphology
• Paleoindian
• Great Basin

Disclosure statement

No potential conflict of interest was reported by the author(s).

Acknowledgements

We thank the Klamath Tribes, Fort Bidwell Indian Community, Burns Paiute Tribe, and Confederated Tribes of Warm Springs for the opportunity to conduct research at Connley Caves, which are situated within their traditional territories. Special thanks to the MNCH Field School students who helped make this study possible. We also thank William Cannon, the Lakeview District Bureau of Land Management, and University of Oregon Museum of Natural and Cultural History for the many years of support for Connley Caves research. Partial funding of this project was provided by the Geological Society of America’s Graduate Student Research Grant (JAH). Finally, we are grateful for the feedback we received from the two anonymous reviewers whose comments and suggestions greatly improved this manuscript.

Additional information

Notes on contributors

Justin A. Holcomb

Justin A. Holcomb (PhD, Boston University) is Postdoctoral Researcher within the Kansas Geological Survey at the University of Kansas. He is an anthropological archaeologist with a focus on the geoarchaeology of human-environment interaction. His research interests include site formation processes and human dispersals, especially in the context of the peopling of new landscapes (Americas, Aegean Basin, Solar System).

Katelyn N. McDonough

Katelyn McDonough (PhD, Texas A&M University) is an Assistant Professor of Anthropology and Director of the Museum of Natural and Cultural History Archaeology Field School at the University of Oregon. She is an environmental archaeologist who studies relationships between people, foodways, disease, and ecosystems, with an emphasis on the Pleistocene-Holocene transition in western North America.

Richard L. Rosencrance

Richard L. Rosencrance is currently a PhD student at the University of Nevada, Reno and instructor at the University of Oregon archaeological field school. He earned his MA at the University of Nevada, Reno in 2019. His research interests include the peopling of the Americas, the Western Stemmed Tradition, chronology building, lithic technology, and human adaptive strategies in the Great Basin and Columbia Plateau.

Lisa-Marie Shillito

Lisa-Marie Shillito (PhD, University of Reading) is a Professor of Geoarchaeology and Director of the Wolfson Archaeological Laboratory at Newcastle University. Her research focuses on using soil micromorphology, phytolith analysis, and geochemistry to understand human behavior and landscape change.

Dennis L. Jenkins

Dennis L. Jenkins (PhD, University of Oregon) is a Senior Research Archaeologist II and emeritus Director of the Northern Great Basin archaeological field school at the University of Oregon Museum of Natural and Cultural History. His research interests include the first settlement of North America, Northern Great Basin archaeology, obsidian sourcing and hydration, and Great Basin settlement-subsistence patterns.