THE CAROLINA BAYS

Theories of Origin
 


More than a dozen bays are shown in this photo in southeastern North Carolina. Several are cleared and drained for farming.Various theories have been proposed to account for them, including action of sea currents when the area was under the ocean or the upwelling of ground water at a later time. The current theory within the earth sciences academic community is that a combination of processes including climate change, the formation of siliclastic karst by solution of subsurface material during glacial sealevel lowstands and later modification of these depresssions by periodic eolian and lacustrine processes created the shapes and orientations of these ancient landforms.

Various proposals that they were either directly or indirectly created by a meteorite shower or exploding comet are disputed by many scientists for an apparent lack of extraterrestrial material, absence of shocked quartz and "bedrock" deformation associated with larger bays, and extremely low ratio of depth to diameter of the larger bays. More information on these theories can be found at: Carolina Bays.

Quaternary geologists and geomorphologists argue that the peculiar features of Carolina Bays can be readily explained by known terrestrial processes and repeated modification by eolian and lacutrine processes of them over the past 70,000 to 100,000 years. Also, Quaternary geologists and geomorphologists believe to have found a correspondence in time between when the active modification of the rims of Carolina Bays most commonly occurred and when adjacent sand dunes were active during the Wisconsin glaciation between 15,000 and 40,000 years and 70,000 to 80,000 years BP.

In addition, Quaternary geologists and geomorphologists have repeatedly found that the orientations of the Carolina Bays are consistent with the wind patterns, which existed during the Wisconsin glaciation as reconstructed from Pleistocene parabolic dunes, at time when the morphology of the Carolina Bays were being modified.