A model for the geomorphology of the Carolina Bays
Abstract
Geometrical analysis of the Carolina Bays using Google Earth in combination with LiDAR data makes it possible to postulate that the bays formed as the result of impacts, rather than from eolian and lacustrine processes. The Carolina Bays are elliptical conic sections with width-to-length ratios averaging 0.58 that are radially oriented toward the Great Lakes region. The radial distribution of ejecta is one characteristic of impacts, and the width-to-length ratios of the ellipses correspond to cones inclined at approximately 35°, which is consistent with ballistic trajectories from the point of convergence. These observations, and the fact that these geomorphological features occur only on unconsolidated soil close to the water table, make it plausible to propose that the Carolina Bays are the remodeled remains of oblique conical craters formed on ground liquefied by the seismic shock waves of secondary impacts of glacier ice boulders ejected by an extraterrestrial impact on the Laurentide Ice Sheet. Mathematical analysis using ballistic equations and scaling laws relating yield energy to crater size provide clues about the magnitude of the extraterrestrial event. An experimental model elucidates the remodeling mechanisms and provides an explanation for the morphology and the diverse dates of the bays.
- Publication:
-
Geomorphology
- Pub Date:
- April 2017
- DOI:
- 10.1016/j.geomorph.2017.01.019
- Bibcode:
- 2017Geomo.282..209Z
- Keywords:
-
- Impact cratering;
- Geomorphology;
- Crater remodeling