The mosaic of images that began the C-bay-origin debate.
Click the image for more info.
Recent (2005) photos of C-bays
The Age and Tropic History of Lake Waccamaw, North Carolina
Sediment cores were collected in Lake Waccamaw, a Bay Lake in southeastern North Carolina. The cores were analyzed for information that might be relevant to concerns about the age and trophic status of the lake which is home to several endemic species. Analysis of the diatoms and sponge spicules in the sediments revealed that the lake has always been nearly eutrophic. Analyses of sediment carbon and phosphorus content also support this view. The sediment record indicates that Lake Waccamaw has had periods of shallowing followed by deeper phases. Our interpretation of the geologic history of the Lake Waccamaw area, the sediment record, and the relevant data of others is that Lake Waccamaw is a relatively young lake, probably around 15,000 years old or less. The presence of endemic fauna in the lake is probably a result of the lake's unique chemistry and productivity and not the result of a long period of reproductive isolation from other populations.
Clay Mineralogy of Some Carolina Bay Sediments
Kaolinite, a 14 Ao clay mineral, and illite were identified in 23 samples collected from five Carolina Bays in southern North Carolina. The 14 Ao clay mineral does not have the characteristics of any of the usual 14 Ao clay minerals and can with some justification be called expanded illite, vermiculite, chlorite, or montmorillonite. White Lake and Singletary Lake, both near Elizabethtown, have a kaolinite - 14 Ao clay mineral - illite assemblage; and three small sediment-filled bays near Laurinburg have a kaolinite - 14 Ao mineral assemblage. The available facts are consistent with the conclusion that the clay minerals in the bay sediments were washed or blown into the bays from surrounding surficial Pleistocene (?) sediments and that they have undergone little alteration since deposition.
The Carolina Bays
William F. Prouty's contention (1952) that the Carolina Bays were formed by impact has not been refuted by direct evidence nor has it been tested by more modern methods. Recently, however, several papers have been published which relate evidence that could be viewed as supportive of Prouty's hypothesis. For instance, P.S. Martin's "over-kill" scenario is in trouble due to finds of mammoths in Europe which date 5,000 years younger than earlier discovered specimens. This closes the gap between the youngest date for mammoths in America (10,500 B.P.) and for Europe (12,000 B.P.) to 1,500 years (see G.R. Coope and A.M. Lister, Nature Vol. 330, 3 Dec. 87, pp. 472-474)
A Re-evaluation of the Extraterrestrial Origin of the Carolina Bays
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.
Fire &Water: A Bobs view on Carolina Bay formation
In that there has been an increasing interest in the Carolina Bays as possible impact features I felt that the reader might like to know of my own opinion on how these features came to be. Simply put, I believe that these near flat, shallow, structures were formed by terminal flare induced steam explosions of wet exposed ground.
A recent Mammoth Trumpet article that shows evidence of neutron bombardment ~12,500 years ago. Terrestrial Evidence of a Nuclear Catastrophe in Paleoindian Times, by Richard B. Firestone and William Topping. (in PDF format) (html version, sans figures, etc.)
Speculation on the possibility of generating neutron radiation from deuterium rich carbonaceous material. Could an impact with a comet produce the evidence Topping and Firestone present in the article above?
Beavers and Bays
One of the intriguing aspects of the Carolina Bays is that they frequently overlap one another. Prouty reasoned that bays impinging on other bays were the result of multiple, serial, impacts with the last in the sequence retaining the common Carolina Bay form. A problem with this method of creating Carolina Bays is that the rim height of ostensibly later formed bays is generally about the same height as the rim of those bays that were impinged upon. It is difficult to find a convincing way for multiple impacts to produce a bay within a bay with a rim height that matches the bay that contains it. The gloss over to this hard to account for property is that the bays are so shallow that virtually any rim height would be enough to bring later formed bays up to about the level of the earlier formed bays. This is a weak explanation and also points to another problem with a direct impact modelthe shallowness of the features.
A Comprehensive Bibliography of the Carolina Bays Literature
Carolina Bays research has been conducted for more than a century and the results of the research efforts have appeared in a multitude of journals, books, and monographs. More than 350 bibliographic entries have been identified here, most of which pertain directly to Carolina Bays. The remainder provide insights and information important to the scientist engaged in Carolina Bays studies. Examination of the literature shows that the focus of research has shifted over the years. Most of the early work concentrated on theories of origin. For the past several years ecology, limnology, and soil characteristics have received more attention than origin studies.
Some considerations with regard to large comets:
A major difference in possible damage to the biosphere across the potential physical size range of Earth orbit crossing objectsEOCOsis the increased capacity for larger EOCOs to produce adverse effects without a direct impact. In other words, an EOCO 1 km across, with sufficient relative velocity to avoid being captured by Earths gravity, could come within 1,000 km of Earths surface and cause no problem; a 100 km across EOCO with the same velocity is not apt to make such a clean get away.
The Goldsboro ridge, an enigma:
This ridge, which we call the Goldsboro ridge, is oriented northwest-southeast and is only 3/4 mile wide. The ridge is between West Bear Creek and Walnut Greek and is completely surrounded by nearly level topography with a relief of about 5 feet. It is slightly asymmetric and is steeper on the southwest side. It has a gently undulating crest and two distinct Carolina bays at the southeast end.
Carolina Bays in the upland gravels of Virginia
Circular to elliptical depressions occur on relatively undissected tracts of upland gravels at altitudes of 350 to 370 feet. The depressions which are less than 15 feet deep are commonly bounded by a raised rim. They vary in maximum diameter from a few hundred feet to more than three quarters of a mile. Their centers are often swampy due to the lack of external drainage. These depressions are tentatively designated as Carolina Bays.
The Ecology of Southeastern Shrub Bogs (Pocosins) and Carolina Bays: A Community Profile
This is a 1982 publication of the U.S. Department of the Interior, Fish and Wildlife Service, that provides a good overview of the Carolina Bays. (DjVu format )
The Romance of the Beaver
This is a 1914 publication on the history of the beaver in the Western Hemisphere, by A. Radclyffe Dugmore. (DjVu format )
The Origin of the Carolina Bays
This is a 1942 study of the Carolina Bays by Professor Douglas Johnson of Columbia University. The book provides many images and geologic details of these features. This fully searchable publication, in the DjVu format, was kindly made available for academic use, by permission from Columbia University Press. Please respect their copyrights.
The Mysterious Carolina Bays
This is a 1982 study of the Carolina Bays by Henry Savage Jr. The book provides many images and geomorphic details of these features. It also provides a history of research as well as a comprehensive bibliography. This fully searchable publication, in the DjVu format, was kindly made available for academic use, by permission from The Nature Conservancy. Please respect their copyrights.
Mysterious Carolina Bays still intrigue scientists
Carolina Bays Fact Sheet
The Riddle of the Carolina Bays
A recent essay on the Carolina Bays
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