T116 A Healthy Dose of Quaternary Geochronology at the Shoreline: Applications of Luminescence and Other Dating Techniques to Resolving the Timing of Coastal, Estuarine, and Lake Shore Processes

Monday, 5 November 2012
3:45 PM - 5:30 PM
201AB

CAROLINA BAY FORMATION AND EVOLUTION: KACZOROWSKI WAS RIGHT!

Paper number: T116-1
Program: Technical Sessions
Time: 3:45 PM – 4:05 PM

Authors

  • Christopher R. Moore Presenting Author
    Savannah River Archaeological Research Program, South Carolina Institute of Archaeology and Anthropology,USC, New Ellenton, SC
  • Mark J. Brooks
    Savannah River Archaeological Research Program, South Carolina Institute of Archaeology and Anthropology, USC--Retired, Batesburg, SC
  • Andrew Ivester
    University of West Georgia, Carrollton, GA
  • Terry Ferguson
    Wofford College Environmental Studies, Spartanburg, SC
  • James K. Feathers
    University of Washington, Seattle, WA

Abstract

Carolina bays are oriented, shallow upland ponds occurring on the Atlantic Coastal Plain from New Jersey to North Florida. Historically, Carolina bays have received attention from those speculating on a catastrophic emplacement through cometary, meteoric, or airburst impacts. Recently, it has even been speculated that bays formed from steam outgassing within superheated distal ejecta from an impact over the Great Lakes region. In this scenario, Quaternary-aged cover sands along the eastern seaboard, including "enigmatic" sand ridge scarps (e.g., Goldsboro Scarp) and Carolina bays, are purported to be causally linked to a catastrophic impact. Carolina bay shape, orientation, and sand rims are all used as evidence for an alignment with an impact crater not observed and not known to exist. Other researchers have posited that bays are linked with the purported Younger Dryas comet impact/airburst at ca. 12.9 ka, whereby bay formation was through aerial air-bursts or through a rain of distal impact ejecta to form oblique craters.

While these claims persist, our data indicate that Carolina bay origin and evolution are much better explained through more mundane, uniformitarian processes. The evidence gathered from Carolina bays in South Carolina and beyond demonstrate bay genesis as oriented lakes and formation through lacustrine processes of wind on shallow ponded water. Ray Kaczorowski's wind table modeling in 1977 revealed quite clearly how unidirectional winds on ponded water produce subaqueous circulation cells that shape and orient the bays, while constructing their sand rims as high-energy shoreline features.

More recent work, including GPR, granulometry, OSL dating, and evidence from examination of LiDAR data, reveals that bays reflect long-term, pervasive and evolving environmental and climatological factors over millennia, not sudden or catastrophic events. Thus, a catastrophic origin is neither supported by geological data, nor needed to explain features we attribute to Carolina bays; Carolina bays are neither enigmatic, nor mysterious, but rather are relatively well understood oriented lakes. While nuances of bay formation through lacustrine shore processes remain to be resolved, the fundamental concepts are well understood and have been for some time. Kaczorowski was right!