Reconstructing Terminal Pleistocene-Early Holocene Environmental Change at Page-Ladson, Florida Using Diatom Evidence

ABSTRACT

The Page-Ladson site, currently buried and submerged in a sinkhole in northwestern Florida, demonstrates evidence of human occupation in North America by 14,550 calendar years ago (cal yr BP). This paper combines new diatom evidence with existing palynological data to strengthen paleoenvironmental interpretations at the site. The Page-Ladson sinkhole was not entirely submerged between ∼15,100 and 14,400 cal yr BP. Conditions at the site became warmer and wetter, and the sinkhole became a turbid pond from ∼14,400 to 12,900 cal yr BP. From ∼12,900 cal yr BP until ∼11,000 cal yr BP, a disappearance of diatoms in the coring location suggests the sinkhole margin was dry. Water levels rose between 11,000 and 9000 cal yr BP, submerging the coring location on the pond margin. These environmental data help contextualize the archaeological data in the region.

KEYWORDS:

• Page-Ladson
• diatoms
• Sporormiella
• Late Quaternary environments

Acknowledgements

Thank you to J. and B. Ladson and the Ladson family for site access and assistance with the project; E. Green, T. and B. Pertierra, J. Simpson, and S. Ellison for fieldwork, equipment, and logistics support; LacCore for core storage, analysis, and assistance; Capital Rubber, University of Wisconsin–La Crosse, Wakulla Dive Center, the Center for Maritime Archaeology and Conservation at Texas A&M University, and Florida Bureau of Archaeological Research Underwater Archaeology Division for field equipment and technical support; and to J. Albertson, S. Joy, M. Smith, D. Thulman, G. Farr, N. Puckett, and B. Fenerty for assistance in collecting the cores. Thank you also to the three anonymous reviewers whose comments were helpful in improving the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Angelina Perrotti earned her PhD in Anthropology from Texas A&M University and is currently an Assistant Professor of Anthropology at Arkansas Tech University. Current research interests include late-glacial environments of North America, the use of coprophilous fungi as indicators of megaherbivore abundance, and the peopling of the Americas.

Barbara Winsborough earned her PhD from the University of Texas at Austin, Division of Biological Sciences. Dr Winsborough is an independent consultant. Her specialty is the taxonomy and ecology of diatoms and using diatoms to interpret ancient paleoenvironments. A major focus of her research has been to expand the application of diatom paleoecology as a tool in addressing archaeological questions. She has used diatoms to identify el Niño events, river floods, tsunamis, and climate shifts.

Jessi J. Halligan earned her PhD in Anthropology from Texas A&M University in 2012. She is an Assistant Professor of Anthropology at Florida State University. Her research focuses upon the geoarchaeology of inundated terrestrial sites, including environmental reconstructions and site-formation processes related to sea-level rise. This research is especially focused upon understanding terminal Pleistocene archaeological sites and the peopling of the Americas.

Michael R. Waters earned his PhD in Geosciences from the University of Arizona in 1983. He is a Distinguished Professor of Anthropology at Texas A&M University and Director of the Center for the Study of the First Americans. His research interests focus on understanding the late-Pleistocene peopling of the Americas through archaeological, geoarchaeological, genetic, and paleoenvironmental investigations.

ORCID

Angelina G. Perrotti http://orcid.org/0000-0001-6003-0082

Jessi J. Halligan http://orcid.org/0000-0002-1971-9416

Additional information

Funding

This work was funded by the Elfrieda Frank Foundation; the North Star Archaeological Research Program and the Chair in First Americans Studies at Texas A&M University; The University of Wisconsin-La Crosse; National Geographic Waitt Foundation grant W224-12; Geological Society of America (GSA) graduate research grant 10445-14; the Society for American Archaeology Geoarchaeology Interest Group MA/MS Research Award; the Texas A&M Department of Anthropology; and the Claude C. Albritton Jr Award of the Archaeological Geology division of the GSA.