CAROLINA BAYS STRUCTURE
- Type: Simple
- Age: 12,000 to 140,000 years ago a
- Diameter: <100 metres
- Location: Carolinas USA
a age has not been firmly quantified
The Carolina Bays
Carolina Bays are marshy, shallow depressions with sandy rims that occur in sandy, unconsolidated ground close to the water table. They are located along the Atlantic seaboard, but similar bays are also found in Nebraska and Kansas, where they are called “rainwater basins”. The bays in these Midwestern states differ from the ones in the East Coast in that their major axes are aligned from the northeast to the southwest, almost perpendicular to the orientation of the east coast bays. Projections along the length of the Nebraska bays and of the Carolina bays intersect around the Great Lakes, hinting that whatever created the bays radiated from the Great Lakes Region.
The bays in Nebraska occur at altitudes of 400 to 900 meters above sea level, which is about 1,300 to 3,000 feet above sea level. The sandy soils of Kansas and Nebraska once were the shores of the Western Interior Seaway of North America which disappeared by the Paleocene Epoch 60 million years ago when the Laramide Orogeny uplifted the Rocky Mountains region. These bays near the geographic center of the United States are 2000 kilometers away from the Atlantic and Pacific oceans. Fewer bays can be seen in the Midwestern states because only the larger bays have endured the erosion by rain and the accumulation of layers of wind-blown dust and silt.
Here is a summary of the main morphologic characteristics of the Carolina Bays (Eyton 1975):
- The width-to-length ratio averages 0.58 for both, the Carolina Bays and the Nebraska rainwater basins.
- The Carolina Bays are ellipses although some lack bilateral symmetry along either the major or minor axis. The southeast portion of many bays is more pointed than the northwest end and the northeast side bulges slightly more than the southwest side. Known major axis dimensions vary from approximately 60 meters to 11 kilometers.
- The Carolina Bays display a northwest-southeast orientation. Deviations from this orientation appear to be systematic by latitude (Prouty, 1952).
- The bays are shallow depressions below the general topographic surface with a maximum depth of about 15 meters. Large bays tend to be deeper than small bays, but the deepest portion of any bay is offset to the southeast from the bay center.
- Many bays have elevated sandy rims with maximum development to the southeast. Rim heights vary from 0 to 7 meters.
- Carolina Bays frequently overlap other bays without destroying the morphology of either depression. One or more small bays can be completely contained in a larger bay.
- The stratigraphy beneath the bays is not distorted (Preston and Brown, 1964; Thom, 1970).
- Bays occur only in unconsolidated sediments. Bays in South Carolina are found on relict marine barrier beaches associated with Pleistocene sea level fluctuations, in dune fields, on stream terraces and sandy portions of backbarrier flats (Thom, 1970). No bays occur on modern river flood plains and beaches.
- Carolina Bays appear to be equally preserved on terraces of different ages and formational processes.
- Bays are either filled or partly filled with silt of organic and inorganic origin. Ghosts of semi-obliterated Carolina Bays appear to represent former bays which were filled by terrestrial sediments and organic materials.
In 1933 Melton and Schriever published one of the first publications to ascribe an impact origin to the Carolina Bays. The publication was later criticized by Johnson in 1942 and studied by Prouty in 1952.
“The Carolina ‘Bays’ – Are They Meteorite Scars?”
Melton, F. A., and Schriever, W. 1933. Journal of Geology
ABSTRACT: Aerial photographs of a district on the coastal plain of South Carolina reveal hitherto unknown relationships among surface depressions of a peculiar type, the origin of which has long been a subject of speculation. These relationships include (1) a smoothly elliptical shape, (2) parallel alinement in a southeastern direction, (3) a peculiar rim of soil which, with unimportant exceptions, is invariably larger at the southeastern end than elsewhere, and (4) mutual interference of outline. Consideration of all of these facts leads to the conclusion that the origin is not directly attributable to ordinary geologic processes. On the contrary, a hypothesis involving impact by a cluster of meteorites is presented as the most reasonable explanation. The supposed swarm must have been large enough to possess a cross-sectional area at right angles to the direction of movement of the order of magnitude of 50,000 square miles.
The research completed by Professor Johnson refuted the bolide impact hypothesis for Carolina Bays origin.
The Origin of the Carolina Bays
Douglas Johnson. © 1942 Columbia University Press
Bay morphology and morphometry is used to refute an astronomical origin for the Carolina Bays. The bays lack the elevated structural rims associated with known meteorite impact craters; craters tend to be deep and round whereas the bays are shallow ellipses; known meteor crater clusters do not result in thousands of depressions across a wide area; and, no known meteorites are genetically related to bays.
Dr. Prouty uses the shape of the Carolina Bays to assume a meteoritic impact origin but does not have impact evidence.
CAROLINA BAYS AND THEIR ORIGIN
W. F PROUTY, 1952
Abstract: The Carolina Bays have a known distribution along the Atlantic Coastal Plain from northeast Florida to southeast New Jersey. Estimates based on actual counts in limited regions indicate a conservative figure of half a million bays in the entire area. Local areas show over 50 per cent coverage by bays.
Statistical studies of orientation show a greater divergence of smaller bays from the mean than of larger bays. Smaller bays also show greater variation in ellipticity than do larger bays. Both facts are most satisfactorily explained by the meteoritic theory of origin. Multiple and “heart-shaped” bays overlap in patterns explained most logically by the impact of tandem meteorites, some likely explosive in nature. The probable mechanics of such phenomena is illustrated. Study of near-coast bays indicate that the bays are younger than the youngest Pleistocene terrace and some of the Coastal Plain drainage and older than at least one of the more recent marine transgressions.
Magnetometer studies of 26 different bays all indicate associated spot highs, with no definite highs observed that are not readily associated with some bay.
Laboratory experiments with projectiles involving simulated Coastal Plain conditions duplicate remarkably the cross-section and rim characteristics of the Carolina Bays and strengthen the meteoritic theory.
Although the meteoritic theory in general is indicated by all critical analyses of the bays, a modified meteoritic theory (air-shock wave) is offered to better explain additional data.
Dr. Eyton proposed shock waves from cometary fragments exploding above the surface creating the series of Carolina Bays.
by J. Ronald Eyton & Judith I. Parkhurst
ABSTRACT: Controversy as to the origin of the Carolina Bays has centered on terrestrial versus extraterrestrial theories. Meteoritic impact has been considered the primary causal mechanism in extraterrestrial models, but alternatives such as comets and asteroids have not been adequately considered. Comets may explode during fall and produce depressions which would conform to the morphology of the Bays. Only a comet appears to satisfy the constraints imposed both by extraterrestrial requirements and observed terrestrial characteristics.
Mr. Antonio Zamora posits that the conical craters were formed on ground liquefied by secondary impacts of glacier ice boulders ejected from a primary impact site somewhere on the North American ice age glacier.
Interpreting Carolina Bays as Glacier Ice impacts – Video Presentation
Antonio Zamora, 2014
ABSTRACT: The origin of the Carolina Bays remains a mystery more than eighty years after their discovery. This paper explores the hypothesis that the Carolina Bays were formed as the result of impacts of glacial ice ejected when a meteorite struck the Laurentide ice sheet in the Great Lakes region. A new impact model describes the elliptical Carolina Bays as conic sections representing the intersection of the tilted conical craters formed by the oblique entry of the glacier chunks with the level surface of the Earth. Melting of the ice impactors created pools that became shallower through viscous relaxation of the substrata and deposits of terrestrial sediments. The impact model can be used to predict the location where stones carried by the glacial ice impactors may have been deposited.
Brent Dalrymple, Radiometric Dating Does Work! Reports of the National Center for Science Education
Eyton, J.R; Judith I. Parkhurst A Re-Evaluation Of The Extraterrestrial Origin Of The Carolina Bays, 1975
Melton, F. A., and Schriever, W. 1933. “The Carolina ‘Bays’ – Are They Meteorite Scars?” Journal of Geology, Vol. 41, pp. 52-66.
Johnson, Douglas, The Origin of the Carolina Bays, 1942 Columbia University Press
Prouty, W. F., 1952. Carolina Bays and their Origin, Bulletin, Geological Society of America, vol. 63, pp. 167-224.
Antonio Zamora, Solving the Mystery of the Carolina Bays