Bayesian Revision of the Folsom Age Range Using IntCal20

ABSTRACT

Folsom is an early Paleoindian archaeological tradition found in the North American West. Here we report new AMS radiocarbon dates for the Barger Gulch and Lindenmeier sites in Colorado along with unsuccessful dating attempts for Blackwater Draw, the Mitchell Locality, Shifting Sands, and Lipscomb on the Southern Plains. We applied Bayesian modeling using IntCal20 to our updated set of Folsom dates and estimate that the Folsom tradition lasted for a period spanning between 355–510 years at the 68 per cent credible interval or 325–650 years at the 95 per cent credible interval, starting sometime between 12,845–12,770 calendar years ago (cal yr BP) and ending sometime between 12,400–12,255 cal yr BP. Additionally, we model the spans of the start and end boundaries and find that both the adoption and abandonment of Folsom technology occurred over relatively short periods, less than 100 years and likely less than 50 years.

KEYWORDS:

• Folsom
• radiocarbon dating
• Bayesian
• Barger Gulch
• Lindenmeier

Disclosure statement

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

Acknowledgements

This work was partially funded with a University of Tulsa Faculty Research Grant and the University of Wyoming. The authors wish to thank Alan Osborn and the University of Nebraska State Museum for the Lipscomb samples and Richard Rose for the Shifting Sands samples.

Notes

1 We report 33 reliable Folsom dates from the Surovell et al. (2016) study. This number excludes two dates (UCIAMS-122571 and SI-3733) reported from the Agate Basin site that Surovell et al. (2016) suggest may have been contaminated and the two charcoal dates (Beta-173385 and Beta-173381) from Barger Gulch that have been replaced by the calcined dates reported in this study.

Additional information

Funding

This work was supported by University of Tulsa and the University of Wyoming.

Notes on contributors

Briggs Buchanan

Briggs Buchanan is an Associate Professor at the University of Tulsa in Tulsa, Oklahoma. He studies Paleoindian archaeology, lithic technology, and cultural evolution.

J. David Kilby

David Kilby is an Associate Professor at Texas State University and Director of the Ancient Southwest Texas project. Current field research is focused on Bonfire Shelter and the Paleoindian occupation of the Lower Pecos region. His interests include North American Paleoindians, hunter-gatherers, geoarchaeology, lithic technological organization, paleoenvironments, landscape archaeology, and behavioral ecology.

Marcus J. Hamilton

Marcus J. Hamilton is an Associate Professor of Anthropology at the University of Texas at San Antonio, and previously held positions at the University of Missouri, the Santa Fe Institute, and the University of New Mexico. He researches hunter-gatherer societies in the past and present, particularly focusing on the evolutionary ecology of human-environment interactions. His archaeological area of interest is Paleoindian North America.

Jason M. LaBelle

Jason M. LaBelle is an Associate Professor of Anthropology at Colorado State University, where he directs the Center for Mountain and Plains Archaeology. Over the past 25 years, he has supervised field and lab projects related to hunter-gatherer reoccupation, variation in Paleoindian sites, thermal features, high altitude game drives, Fremont granaries, and lithic caches.

Kelton A. Meyer

Kelton A. Meyer is a PhD student in the Department of Anthropology and Geography at Colorado State University. He is a field and lab director for the Center for Mountain and Plains Archaeology. His current research focuses on high altitude settlement systems in the Rocky Mountains, Paleoindian lithic technology, and spatial statistical modeling.

Jacob Holland-Lulewicz

Jacob Holland-Lulewicz is currently Lecturer in Archaeology at Washington University in St. Louis. His research applies quantitative methods to the exploration of the long-term Indigenous histories of North America with a particular focus on the evolution of social networks and institutions of governance.

Brian Andrews

Brian Andrews is an Associate Professor of social science at Rogers State University in Claremore, Oklahoma. He has conducted archaeological research throughout the Great Plains and Rocky Mountains, examining questions of mobility, settlement, technology, spatial patterning, and social organization.

Brooke M. Morgan

Brooke M. Morgan is Curator of Anthropology at the Illinois State Museum. Her research interests include lithic technology, hunter-gatherer community organization, and engaging with descendant communities.

Brendon Asher

Brendon Asher is the Director of the Blackwater Draw National Historic Landmark archaeological site and an Assistant Professor of anthropology at Eastern New Mexico University. His research includes Paleoindian lithic technology, lithic procurement, and landscape use.

Vance T. Holliday

Vance T. Holliday received his PhD in Geosciences from the University of Colorado in 1982. He was on the Geography faculty at the University of Wisconsin-Madison (1986-2002) and is now in both Anthropology and Geosciences at the University of Arizona. He is Executive Director of the Argonaut Archaeological Research Fund, devoted to exploring the early peopling of the greater Southwest. His interests include Paleoindian archaeology and geoarchaeology as well as Quaternary soils and paleoenvironments, and Paleolithic geoarchaeology of eastern Europe.

Gregory W. L. Hodgins

Greg Hodgins is the Director of the University of Arizona Accelerator Mass Spectrometry Laboratory. His research focuses on archaeological and geological dating.

Todd A. Surovell

Todd Surovell is a Professor of Anthropology at the University of Wyoming. He has expertise in Paleoindian archaeology, geoarchaeology, ethnoarchaeology, and lithic technology.