A Southeastern North America River Community Forty-Thousand Years Ago

Authors

Zack J. Quirk, University of Michigan Ann ArborFollow
Dennis B. Blanton, James Madison UniversityFollow

Abstract

Understanding how past communities have been shaped by environmental alterations can provide insight into the impacts of future climate change. Local climate and river systems have changed significantly over the last glacial maximum, but little is known about the communities of the Georgian Coastal Plain earlier in the period. Plant fossils from Coffee Bluff, a Quaternary organic river deposit of the Ocmulgee River in southeastern Georgia, were used to determine past environmental and climatic conditions. The paleoflora were found imbedded in a mud matrix and were removed by a slaking method; they were later identified and separated to respective ecological environments. Of the eleven species identified, one was a wetland species (marsh sedges), while the remaining ten were woodland species. From using the coexistence approach with the plant fossils and aligning their growing conditions, we suggest that Coffee Bluff was a stream/riverine habitat with loamy and well-drained soils; local climate was humid, with temperatures and annual precipitation ranging from 10 to 21⁰C and 1016 to 1524 mm, respectively. Few gymnosperm specimens were recovered in the material, though groups like conifers were dominant in the coastal plain environment during the late Pleistocene. It is most likely that there were fewer conifer trees near the collection area.

Acknowledgements

The first author wants to graciously thank the Fernbank Museum of Natural History for the permission to use and analyze the material that was found during their archaeological expedition of 2006. Both authors thank Frankie Snow for his advice and help with information regarding the material’s origins. Both authors also value the access to the property provided by the landowner, Glass Land & Timber Co., LLC. Both authors also kindly thank Dorothy Peteet for her invaluable help with identification of the plant macrofossils. The first author would also like to thank Melanie DeVore and Kathleen Pigg for their invaluable insight. The original paper was greatly improved with comments by John Tarduno, Penny Higgins and Rory Cottrell.

Recommended Citation

Quirk, Zack J. and Blanton, Dennis B. (2020) "A Southeastern North America River Community Forty-Thousand Years Ago," Georgia Journal of Science, Vol. 78, No. 2, Article 6.
Available at: https://digitalcommons.gaacademy.org/gjs/vol78/iss2/6