Refit and Oxygen Isotope Analysis of Freshwater Mussel Shells from the Tillar Farms Site (3DR30), Southeast Arkansas

ABSTRACT

We investigate the link between the consumption of foodstuffs, excavation of a large pit, and disposal of waste at the Tillar Farms site (3DR30), southeast Arkansas, using refit and oxygen isotope analyses of well-preserved freshwater mussel shells from Feature 1. Only 0.13% of 7,408 valves analyzed were unidentifiable to species.The refit analysis produced 460 refits across 23 species and strongly indicates that the shell midden represents a single episode of shellfish gathering, consumption, and discard. Oxygen isotope analysis of five randomly selected shells are used as a test of the refit results. δ¹⁸O values from the five archaeological shells are compared to modern control samples of live-collected specimens from Bayou Bartholomew in winter of 2011. Refit analysis suggests the accumulation of mussel shells occurred quickly, likely as a result of one collection, consumption, and discard event. δ¹⁸O values suggest this activity took place during a single winter season.

KEYWORDS:

• Tillar Farms
• oxygen isotope analysis
• freshwater mussel shell
• mussel shell refit analysis
• Bayou Bartholomew

Acknowledgments

We would like to thank John Harris for collecting the modern freshwater mussels from Bayou Bartholomew for us in January 2011. The Arkansas Archeological Survey provided access to and permission to use field records and photographs from Tillar Farms. Analysis of mussel shell was conducted at the Cobb Institute of Archaeology, Mississippi State University, Starkville, Mississippi. Joseph Mitchell aided in acquisition of pertinent literature. Partial funding for the instrumentation at the University of Alabama Stable Isotope Lab (ASIL) used in the project was provided by the National Science Foundation Instruments and Facilities grant number EAR-0949303. We thank Dr. Joe Lambert of the University of ASIL for help with the isotope analyses.

Notes on Contributors

Joe D. Collins is an Assistant Professor in the Department of Geosciences at Middle Tennessee State University. His research focuses on reconstructing ancient environments; the transportation, composition, and characteristics of sediments; and geoarchaeology.

C. Fred T. Andrus is Professor and Chair in the Department of geological Sciences at the University of Alabama. His research primarily utilizes biogeochemical and sclerochronological techniques to address questions of past climate and environmental change using archaeological and fossil remains.

Robert J. Scott is a research assistant at the Arkansas Archeological Survey’s research station at the University of Arkansas–Pine Bluff. His research interests include the Late Prehistoric and Contact Period archeology of the Lower Mississippi Valley.

Amy Moe-Hoffman is an Instructor of Geology in the Department of Geosciences and Curator of the Dunn-Seiler Museum at Mississippi State University. Her research has focused on the reconstruction of paleoclimate using environmental tolerances of extant taxa as an analog for fossil insect assemblages.

Evan Peacock is an evolutionary and environmental archaeologist and Professor Emeritus with the Department of Anthropology & Middle Eastern Cultures at Mississippi State University.

Notes

1 Species names reported in Peacock et alia (2013) updated to accord with Williams et alia (2017).