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E. F. Albin (Fernbank Science Center)
In this investigation, forty-four elliptical depressions, with diameters > 1.0 km, have been mapped across the Georgia (USA) coastal plain. These curious features are often called pocosins (an Algonquin name for a bay-covered swamp); however, in the literature the depressions are the so-called ``Carolina Bays" [1]. Controversy has surrounded the origin of the Carolina Bays since they were first recognized in the late eighteenth century [e.g., 2]. Although terrestrial processes have been invoked to explain their origin, a meteoritic related mode of formation cannot be ruled out. Aerial imagery shows the bays on the Georgia coastal plain as dark ovals surrounded by white to light-gray rims. These rims are composed of sandy deposits that are typically less than two meters high and are better developed in the southeastern part of the oval. Magnetic anomalies occur outside of most bay depressions, approximately the distance of the short axis of the bay away from the southeastern rim. On a regional scale, bay trend is from NW to SE -- with the southern most occurring bays having a slight clockwise orientation relative to those found farther north. Arabia Bay, a 4.5 x 6.0 km feature, in Clinch County is the largest bay identified in Georgia. It is suggested that bays are late Pleistocene features produced by a series of ``Tunguska-like" atmospheric bursts associated with the fall of a massive chondritic or cometary bolide. Associated air-shock waves plowed into soft sediments, across the eastern North American coastal plain (from New Jersey to Georgia), forming a myriad of shallow depressions along its path. Further research, including laboratory modeling and field investigations, is ongoing.
References: [1] Prouty, W.F., 1952, Bull. Geol. Soc. Amer., 63, 167-224. [2] Savage, H., 1982, The Mysterious Carolina Bays, Univ. South Carolina Press, 121 p.
The author(s) of this abstract have provided an email address for comments about the abstract: ed.albin@fernbank.edu