Carolina Bay

Carolina bays are elliptical depressions concentrated along the Atlantic seaboard within coastal Delaware, Maryland, New Jersey, North Carolina, South Carolina, Virginia, Georgia, and northcentral Florida (Prouty 1952, Kaczorowski 1977). In Maryland, they are called Maryland basins (Rasmussen and Slaughter 1955). Other landform depressions, not widely accepted as Carolina bays, are found within the northern Gulf of Mexico coastal plain within southeast Mississippi and Alabama where they are known as either Grady ponds or Citronelle ponds (Otvos 1976, Folkerts 1997). Carolina bays vary in size from one to several thousand acres. About 500,000 of them are present in the classic area of the Atlantic Coastal Plain, often in groups with each bay invariably aligned in a northwest-southeast direction. The bays have many different vegetative structures, based on the depression depth, size, hydrology, and subsurface. Many are marshy; a few of the larger ones are (or were before drainage) lakes. Some bays are predominantly open water with large scattered pond cypress, while others are composed of thick, shrubby areas (pocosins), with vegetation growing on floating peat mats. Generally the southeastern end has a higher rim composed of white sand. They are named for the Bay trees that are frequently found in them, not because of the frequent ponding of water (Sharitz 2003).

Undrained, often circular to oval, depressions exhibiting a wide range of area and depth are also a very common feature of the Gulf of Mexico coastal plain within Texas and southwest Louisiana. These depressions vary in size from 0.4 to 3.6 km (0.25 to 2 miles) in diameter. Within Harris County, Texas, raised rims, which are about 0.65 m (2 ft) high, partially enclosed these depressions. In the scientific literature they are known by a variety of names, including “pocks”, “pock marks”, “bagols”, “lacs ronds”, and “natural ponds” (Aronow nda, ndb).

Similar oval basins occur south of the Platte River on the loess-covered landscape of Nebraska where they are called Rainwater basins. Unlike the Carolina bays, the oval Rainwater basins are the surface expression of elliptical depressions developed in fluvial sands and gravels buried by a blanket of several meter-thick loess. These basins are palimpset landforms created by the draping of a younger loess blanket over these underlying depressions (Zanner and Kuzila 2001). The loess, which overlies these features, contains an intact sequence, from bottom to top, of Middle Wisconsinan Gilman Canyon Formation, Late Wisconsin Peoria Loess, Brady Soil, Holocene Bignell loess resting upon a Late Illinoian Sangamon Soil developed in the fluvial sand and gravels in which these depressions have developed (Zanner et al. 2007). The intact layering of these different loesses and associated paleosols, which are each called “soil” by Zanner et al. (2007), prove that the loess has not been disturbed since it started accumulating over 27,000 years ago. Thus, these buried elliptical depressions are over 27,000 years old (Zanner and Kuzila 2001).

Ecological Significance and Biodiversity

The bays are especially rich in biodiversity, including some rare and/or endangered species. Species that thrive in the bays' habitats include birds, such as wood storks, herons, egrets, and other migratory waterfowl, mammals such as deer, black bears, raccoons, skunks, and opossums. Other residents include dragonflies, green anoles and green tree frogs. The bays contain trees such as black gum, bald cypress, pond cypress, sweet bay, loblolly bay, red bay, sweet gum, maple, magnolia, pond pine, and shrubs such as fetterbush, clethra, sumac, button bush, zenobia, and gallberry. Plants common in Carolina bays are water lilies, sedges and various grasses. Several carnivorous plants inhabit Carolina bays, including bladderwort, butterwort, pitcher plant, and sundew.

Some of the bays have been greatly modified within human history, under pressure from farming, highway building, housing developments and golf courses. Carvers Bay, a large one in Georgetown County was used as a bombing practice range during World War II. It has been drained and is mostly used for tree farming today. Others are used for vegetable or field crops with drainage.

In South Carolina, Woods Bay, on the Sumter-Clarendon County line near Turbeville has been designated a state park to preserve as much as possible in its natural state. Also in Clarendon County (near Manning) another bay, Bennett's Bay is a Heritage Preserve.

Another bay in Bamberg County, South Carolina is owned by the South Carolina Native Plant Society which has been developing a 52 acre preserve called the Lisa Matthews Memorial Bay, which is trying to preserve and increase the federally endangered wildflower "Oxypolis canbyi" (Canby's Dropwort) in the bay. The uplands area surrounding the bay is being restored from a loblolly pine plantation to the original longleaf pine. Included in the longleaf restoration is the restoration of wiregrass ("Aristida beyrichiana") as a key understory plant. Its flammability aids in periodic burning, which is necessary for Canby's Dropwort and many of the other species unique to the environment.

Orientation

As measured by Johnson (1942) and Kacrovowski (1977), the orientation of the long axes of Carolina Bays systematically rotate northward along the Atlantic Coastal Plain from northern Georgia to northern Virginia. As measured by Johnson (1942) and Kacrovowski (1977), the average trend of the long axes of Carolina Bays varies from N16°W in eastcentral Georgia to N22°W in southern South Carolina, N39°W in northern South Carolina, N49°W in North Carolina, and N64°W in Virginia. Within this part of the Atlantic Coastal Plain, the orientation of the long axes of Carolina Bays varies by 10 to 15 degrees (Johnson 1942, Kacrovowski, 1977, Carver and Brooks 1989). If the long axes of these Carolina Bays, as measured by Johnson (1942), are projected westward, they converge, neither in the Great Lakes nor Canada, but in the area of southeastern Indiana and southwestern Ohio.

At the northern end of the distribution of Carolina Bays within the Delmarva Peninsula, the average orientation of the long axes of Carolina Bays abruptly shifts by about 112 degrees to N48°E. Further north, the orientation of the long axes of Carolina Bays becomes, at best, distinctly bimodal and exhibits two greatly divergent directions and, at worst, completely random and lacking any preferred direction (Kacrovowski, 1977). Plate 3 of Rasmussen and Slaughter (1955), which is reproduced as Figure 51 of Kacrovowski (1977), illustrates the disorganized nature of the orientations of the long axes of Carolina Bays within the northernmost part of their distribution within Somerset, Wicomico, and Worcester counties, Maryland.

At the southern end of their distribution, the Carolina Bays in southern Georgia and northern Florida are approximately circular in shape. In this area, they have a weak northerly orientation (Kacrovowski, 1977). The Carolina Bays in southern Mississippi and Alabama are elliptical to roughly circular in shape. The measurement of the long axes of 200 elliptical Grady / Citronelle ponds found a very distinct orientation tightly clustered about N25°W in southwestern Baldwin County, Alabama (Otvos 1976).

Within the Atlantic Coast Plain, the measured orientation of the long axes of Carolina Bays and the Pleistocene direction of movement of adjacent sand dunes, where present, are generally perpendicular to each other. In southern Georgia and northern Florida, the northerly orientation of Carolina Bays is matched by a westerly orientation of the direction of Pleistocene movement of sand dunes (Markewich and Markewich 1994). Northward from northern Georgia to Virginia, the average orientation of direction of Pleistocene movement of parabolic sand dunes systematically shifts along with the average orientation of the long axes of Carolina Bays as to always lie approximately perpendicular to them. In The Delmarva Peninsula, the 112 degrees shift in the average trend of the long axes of Carolina Bays is also accompanied by a corresponding shift in the average direction of Pleistocene movement of parabolic sand dunes such that their direction of movement is also perpendicular to the long axes of the Carolina Bays as is the case in the rest of the Atlantic Coastal Plain (Carver and Brooks 1989).

Age

The age of the Carolina Bays is constrained by a variety of dating techniques as predating the end of the Pleistocene by ten of thousands to over a hundred thousand years. The techniques, which demonstrate a pre-terminal Pleistocene age for the Carolina Bays, are radiocarbon dating, Optically Stimulated Luminescence (OSL) dating, and palynology.

Radiocarbon dates: As illustrated in [http://www.hallofmaat.com/images/003Fig.jpgFigure 3] of Heinrich (2005), numerous radiocarbon dates have been collected from the sediments, which fill the basins, of Carolina Bays. The majority of these samples, from which these dates were obtained, were collected from cores of undisturbed sediments that filled Carolina Bays in North and South Carolina. These cores were collected to reconstruct region paleoenvironmental records using pollen, diatoms, and other fossils found in the distinctly and conformably layered sediments that fill the Carolina Bays (Brooks et al. 2001, Frey, 1953, Frey 1955, Gaiser et al. 2001, Watts 1980, Whitehead 1981). Additional radocarbon dates have been obtained from organic matter collected from the undisturbed sediments filling Carolina Bays by Blilet and Burney (1957). Kaczorowski (1977), Mixon and Pilkey (1976), and Thom (1970). Many radiocarbon dates, which were obtained from organic matter preserved within undisturbed sediments, which fill Carolina Bays, are greater than 14,000 BP radiocarbon in age. The finite radiocarbon dates range in age from 440 ± 50 to 27,700 ±2,600 BP radiocarbon in age (Whitehead 1981, Gaiser et al. 2001). Some samples are so old that they contained insufficient radiocarbon for dating, which results in "greater than dates". For example, samples from sediments filling Carolina Bays have been dated at greater than 38,000 to 49,550 BP radiocarbon years (Frey 1955, Brooks et al. 2001).

In case of Carolina Bays where multiple radiocarbon dates have been determined from a single core, radiocarbon dates are consistent in terms of their stratigraphic position within a core and accumulation rates calculated from them with only the occasional exception. Given the nature of radiocarbon dating, such discordant dates occasionally occur even in undisturbed deposits, when multiple samples were dated. The occasional discordant date by themselves are meaningless as an indicator of disturbance, contrary to the arguments of Firestone (2006). The intact internal stratigraphy of the bay sediments, their paleosols, and their pollen zones, i.e. as observed by Brook et al. (2001) in case of Big Bay, refutes such arguments.

As discussed by Gaiser et al. (2001), radiocarbon dates reported from any Carolina Bay are all minimum dates for their formation. Because only organic matter can be dated by radiocarbon dating, the reported radiocarbon dates only represents times during which organic matter of some type accumulated in Carolina Bays and was later preserved. At other times, datable organic matter would either not have been preserved as sediment accumulated within them or older organic matter destroyed when they dried out completely. During glacial periods when sea level was 130 meters (400 ft) below present, the water table would have been below the bottom of the vast majority of the bays. At such times, any organic matter would have been destroyed by oxidization and weathering of the lake bottom. Also, at that time eolian processes would have eroded any existing sediments filling the bottom of many bays removing any older lake sediments and the pollen, and datable organic matter. As a result, it is highly unlikely that organic matter dating to the exact age of any Carolina Bay would have been preserved except in the deepest of them. Thus, the oldest radiocarbon date from a Carolina Bay only indicates when the water table rose high enough for a permanent lake or swamp to exist within it (Gaiser et al. 2001).

Optically Stimulated Luminescence (OSL) dating: Over the last several years, Ivester et al. (2002, 2003, 2004a, 2004b, 2007) have dated the sand rims of numerous Carolina Bays using Optically Stimulated Luminescence (OSL) They found sand rims of many Carolina Bays to be as old as 80,000 to 100,000 BP. For example, Ivester et al. (2002) wrote about Flamingo Bay, a Carolina Bay:

In the upper Coastal Plain, dates from Flamingo Bay indicate the rim was active at 108.7 ± 10.9 ka BP and again at 40.3 ± 4.0 ka BP. The nearby Bay-40 had an actively forming sand rim at 77.9 ± 7.6 ka BP. Near the confluence of the Wateree and Congaree Rivers in the middle Coastal Plain, an eolian sand sheet was dated to 74.3 ± 7.1 ka BP.

About Carolina Bays in general, Ivester et al. (2004a) concluded:

Luminescence and radiocarbon dating of inland dunes and Carolina bay rims indicate activity during multiple phases over the past 100,000 years. Some bays have evolved through phases of activity and inactivity over tens of thousands of years, as evidenced both by multiple rims along a single bay and by multiple ages within single rims.

and

Both dunes and bays were active during the Wisconsin glaciation, with ages tending to fall between 15,000 and 40,000 years BP, and near the isotope stage 5/stage 4 boundary 70,000 to 80,000 years BP.

Based on OSL dating, Brooks et al. (1996, 2001), Grant et al. (1998), and Ivester et al. (2002, 2003, 2004b) argue that lacustrine and eolian processes have periodically modified the shape and size of the Carolina Bays during the last 100,000 to 120,000 years. For example, Ivester et al. (2003), using OSL dating, dated the nested, concentric sand rims, which are found in Big Bay, a Carolina Bay in South Carolina. From the outside to the inside the age of the rim becomes progressively younger, i.e. 35,660±2600; 25,210±1900; 11,160±900; and 2,150±300 years BP. These dates demonstrate that Big Bay has shrunk over the last 36,000 years by 1.6 miles (1 km). Ivester et al. (2004a) also found these rims to be composed, not of impact ejecta, but rather "are composed of both shoreface and eolian deposits". Concerning the Carolina Bays, they concluded:

The optical dating results indicate that present-day bay morphology is not the result of a single event, catastrophic formation, but rather they have evolved through multiple phases of activity and inactivity over tens of thousands of years. This is evidenced both by multiple rims of differing ages along the same bay, and by multiple ages within single rims.

On the basis of 45 OSL dates from and sedimentological analyses of rims of Carolina Bays in Georgia and South Carolina, Ivester et al. (2007) concluded that a single Carolina bay was actively modified between 12,000 to 50,000 BP; 60,000 to 80,000 BP; and 120,000 to 140,000 BP. His conclusions is collaborated by the OSL dating done by Brooks et al. (1996, 2001), Grant et al. (1998), and Ivester et al. (2002, 2003, 2004b) on other Carolina Bays and the fact not all Carolina Bays are as perfectly aligned as they are claim to be. In any one location, the orientation of their long axes of Carolina Bays varies by 10 to 15 degrees as discussed in Johnson (1942), Kacrovowski (1977), and Carver and Brooks (1989). Plate 3 of Kacrovowski (1977) also shows the long axes of Carolina Bays becomes, at best, distinctly bimodal and exhibits two greatly divergent directions and, at worst, completely random and lacking any preferred direction within the northernmost part of their distribution, i.e. Somerset, Wicomico and Worcester counties, Maryland. Stratigraphy of Big Bay: The physical relationship of Pleistocene sand dunes to Big Bay, North Carolina, and an adjacent Carolina Bays further demonstrates that they are tens of thousands of years old (Brooks et al. 2001). In this case, during the Pleistocene sand dunes have migrated from the valley wall of the Wateree River into and partially filled Big Bay and an adjacent Carolina Bay. According to basic principles of cross-cutting relationships and superposition, both Carolina Bays were first created and the sand dunes later migrated into them. Thus, the sand dunes must be younger the Carolina Bays. Since the sand dunes have been dated by OSL dating at 29,600±2,4000 to 33,200±2,800 BP, both Carolina Bays must be older than these dates.

Palynology: The sequence of pollen zones recovered from cores taken from various Carolina Bays Frey (1953, 1955), Watt (1980), and Whitehead (1964, 1981) document the presence of full glacial pollen zones within the sediments filling Carolina Bays. The thick sediments, which were recovered in these cores and contain pollen characteristic of full glacial conditions could only have accumulated within these Carolina Bays only if they had existed prior to end of the last glacial epoch. The radiocarbon dates reported by Frey (1953, 1955), Watts (1980), and Whitehead (1964, 1981) from these Carolina Bay cores fully collaborate both the glacial age of the pollen and the undisturbed nature of the sediments filling these Carolina Bays as indicated by the reported layering of the sediments filling them and increasing age with depth of the pollen they contain.

Within cores of undisturbed sediments recovered from Big Bay, North Carolina, Brook et al. (2001) documented well-defined pollen zones consisting of distinct pollen assemblages. They found a stratigraphically consistent series of pollen zones, which increased in age consistently with depth from Holocene interglacial epoch to the Wisconsinan glacial epoch, back into Oxygen Isotope Stage 5, 75,000 to 134,000 years BP. These pollen zones collaborate the dating of Big Bay by OSL and radiocarbon dating.

Theories of Origin

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 created the shapes and orientations of these ancient landforms, including climate change, the formation of siliclastic karst by solution of subsurface material during glacial sealevel lowstands and later modification of these depressions by periodic eolian and lacustrine processes.

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: [http://www.georgehoward.net/cbays.htm 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. [http://eeg.geoscienceworld.org/cgi/content/abstract/5/3/261] . 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 [http://gsa.confex.com/gsa/2004AM/finalprogram/abstract_78899.htm] . 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 [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6R-48C7H09-11W&_user=3787556&_coverDate=11%2F30%2F1989&_rdoc=2&_fmt=summary&_orig=browse&_srch=doc-info(%23toc%235821%231989%23999259996%23567345%23FLP%23display%23Volume)&_cdi=5821&_sort=d&_docanchor=&view=c&_ct=15&_acct=C000061383&_version=1&_urlVersion=0&_userid=3787556&md5=74136fc47efd27f5ca168517637c0d4c] .

The cometary theory, on the other hand, popular among earth scientists of the 1930s and 40's, is that the Bays are the result of an encounter between North America and a low density comet exploding above or impacting with the Laurentide Ice Sheet ~12,900 years ago [http://abob.libs.uga.edu/bobk/cbayint.html] . Supporting evidence includes the failure of "wind and wave" theories to satisfactorily account for a number of the peculiar features of Carolina Bays, including the recent identification of markers suggestive of an extraterrestrial connection, the alignment of bays with points over the Great Lakes, and their tendency to overlap one another from east to west. Extraterrestrial markers include microspherules, magnetic grains with extraterrestrial chemistry, carbon spherules suffused with nanodiamonds, and levels of iridium sixty times background levels. [http://www.pnas.org/cgi/content/abstract/104/41/16016]

The cometary theory was out of fashion in the 50s up until the last few decades among planetary and Quaternary geologists for a number of reasons, in accordance with a general distrust in such theories after some geological features, which were believed to be of catastrophic origin, had been explained with slow changes. In part, because of the lack of any verified terminal Pleistocene crater, which an impact of such magnitude should have created, within the area formerly covered by the Laurentide Ice Sheet. Such features are believed to be found, the proponents of an impact say, in the form of depressions in the Great Lakes, among other potential sites, though none of them are officially recognized in the “Earth Impact Database" [http://www.unb.ca/passc/ImpactDatabase/NorthAmerica.html] . Such an impact site wouldn't even be needed, though, if an explosion in the air (like the Tunguska event) or an impact into one to three kilometers of ice are assumed.

It has been argued that large areas of white sand are due to an immense amount of heat baking the iron, SiO₂Fe -> SiO₂ + Fe. According to this argument, "baking" of the sand by the impacts literally "burns" the iron straight out and redeposits it into the sand. Instead of being a set of a compound, you have pure sand and iron, which go to FeO later as iron oxide. It is argued that the iron is redeposited as magnetic iron oxides in undisturbed sand dunes near all the Carolina Bays.

A basic flaw with this theory for the origin of the “white sand” is that intense high temperatures will not burn off iron-coatings, which originally coated the sand. Typically, these iron coatings consist of iron sesquioxides, which contain varying amounts of water. Any high temperatures will first dehydrate the sesquioxides composing these iron coatings and transform them into pure and very stable iron oxide. As a result, high temperatures will cause opposite from what is argued above to happen. Instead, it will solidly fuse the iron coatings onto the sand grains. Because, the temperature needed to vaporize any iron oxides is greater than the melting point of quartz, the sand will melt into glass long before any iron oxides coating them will be burned off.

In addition, the "white sand" comprising the rims of the Carolina Bays is not unique to them as the above theory incorrectly presumes. The "white sands" found in the rims of the Carolina Bays are identical to well-developed E Horizons, which are found in deeply weathered sandy soils throughout the coastal plains of the Atlantic Ocean and the Gulf of Mexico, including Alabama, Mississippi, Louisiana , and Texas, as is documented in the USDA county soil surveys for this region. Soil Scientists have known for a long time that such E horizons are created by weak organic acids, which strip iron coatings from the sand grains [http://nesoil.com/properties/horizons/sld005.htm] . In soils in which the water table fluctuates, the iron can/will be stripped off when the iron-coated sand is submerged beneath the water table and the iron becomes soluble because of reducing conditions. When the water table drops, the dissolved iron leaves with it precipitates as both magnetic and nonmagnetic iron oxides elsewhere. It is not necessarily contradictive to the impact theory, though, if the white sand comes from an older period and has only experienced slight modifications due to the impact exposing the sand.

After the impact theory as an explanation for the extinction of the dinosaurs has gained credibility among most scientists, more research has been taken in this direction, and more and more impact sites and associated changes are recognised. That also rejuvenated the discussion about the Carolina Bays. In favor of the impact argument, Buckyballs, or C-60 has been reported from the area of a number of the Carolina Bays. This is a spherical material that floats in water, conglomerations of which can be seen sometimes with a microscope, other times with just a hand lens. It is created after carbon is put under high pressure. If the presence of buckyballs can be substantiated by other studies, it might provide significant evidence of an impact.

That would also make the bays an integral part of various other findings associated with the impact event, like a layer of soot found all over North America, drastic climate change, the end of the Clovis culture. The event has come to be called the Clovis comet. [ [http://allendale-expedition.net/publications/comet.pdf THE CLOVIS COMET Part I:Evidence for a Cosmic Collision 12,900 Years Ago] In the Mammoth Trumpet , Volume 23 Number 1, by Allen West GeoScience Consulting and Albert Goodyear South Carolina Institute of Archaeology and Anthropology . Accessed August 2008]

"Carolina Bays: An Annotated Bibliography" by Thomas E. Ross and published by Carolinas Press (ISBN 1-891026-09-7) includes summaries of every academic article published about Carolina bays up to the year 2000.

ee also

Bladen Lake Group

References

* Aronow, S., nda, [http://www.armandbayou.org/watersheds/pdf/Aronow_depression.pdf "A Digression on the origin of some anomalous undrained depressions mostly on the Pleistocene and Pliocene surfaces in the Gulf of Mexico" PDF version, 48 KB] Armand Bayou Watershed Working Group, The Texas Coastal Watershed Program, Houston Texas, 31 pp.
* Aronow, S., ndb, [http://armandbayou.org/watersheds/pdf/Aronow_Harris_geomorph.pdf "Geomorphology and surface geology of Harris County and Adjacent parts of Brazoria, Fort Bend, Liberty, Montgomery, and Waller Counties, Texas" PDF version, 68 KB] Armand Bayou Watershed Working Group, The Texas Coastal Watershed Program, Houston Texas, 23 pp.
* Bliley, D. J., and D. A. Burney, 1988, "Late Pleistocene climatic factors in the genesis of a Carolina Bay". Southeastern Geology. v. 29, no. 2, pp. 83-101.
* Brooks, M. J., B. E. Taylor, and J. A. Grant, 1996, "Carolina Bay geoarchaeology and Holocene landscape evolution on the upper coastal plain of South Carolina". Geoarchaeology. v. 11, no. 6, pp. 481-504.
* Brooks, M. J., B. E. Taylor, P. A. Stone, and L. R. Gardner, 2001, "Pleistocene encroachment of the Wateree River sand sheet into Big Bay on the Middle Coastal Plain of South Carolina". Southeastern Geology. v. 40, pp. 241-257.
* Carver, R. E., and G. A. Brooks, 1989, "Late Pleistocene paleowind directions, Atlantic Coastal Plain, U.S.A. Palaeogeography, Palaeoclimatology, Palaeoecology". v. no. 3-4, pp. 205-216.
*
* Firestone, et al., 2007, "Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling" PNAS 2007 104: 16016-16021; published online before print September 27, 2007, 10.1073/pnas.0706977104
* Folkerts, G. W., 1997, "Citronelle ponds: little-known wetlands of the Central Gulf Coastal Plain". Natural Areas Journal. v. 17, pp. 6-16.
* Frey, D. G., 1953, "Regional aspects of the late-glacial and post-glacial pollen succession of southeastern North Carolina". Ecological Monographs. vol. 23, no. 3, pp. 289-313.
* Frey, D. G., 1955, "A time revision of the Pleistocene pollen chronology of southeastern North Carolina". Ecology. v. 36. no. 4, pp. 762-763.
* Gaiser, E. E., B. E. Taylor, and M. J. Brooks, 2001, "Establishment of wetlands on the southeastern Atlantic Coastal Plain; paleolimnological evidence of a mid-Holocene hydrologic threshold from a South Carolina pond". Journal of Paleolimnology. v. 26, no. 4, pp. 373-391.
* Grant, J. A., M. J. Brooks, and B. E. Taylor, 1998, "New constraints on the evolution of Carolina Bays from ground-penetrating radar". Geomorphology, v. 22, no. 3-4, pp. 325-345.
* Heinrich, P. V., 2005, [http://www.hallofmaat.com/modules.php?name=Articles&file=article&sid=86 "An Evaluation of the Geological Evidence Presented By "Gateway to Atlantis" for Terminal Pleistocene Catastrophe".] [http://www.hallofmaat.com/ Hall of Ma’at web site] .
* Howard, G. A. et al (2007) "Evidence for an Extraterrestrial Impact Origin of the Carolina Bays on the Atlantic Coast of North America" Eos Trans. AGU, 88(23), Jt. Assem. Suppl., Abstract PP42A-05 [http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=sm07&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=carolina%20and%20bays&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c448%7c4520%7cEvidence%20for%20an%20Extraterrestrial%20Impact%20Origin%20of%20the%20Carolina%20Bays%20on%20the%20Atlantic%20Coast%20of%20North%20America%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c5496677%205501197%20%2fdata2%2fepubs%2fwais%2fdata%2fsm07%2fsm07.txt]
* Ivester, A. H., D.I. Godfrey-Smith, M. J. Brooks, and B. E. Taylor, 2002, "Carolina Bays and inland dunes of the South Atlantic Coastal Plain yield new evidence for regional paleoclimate". Geological Society of America Abstracts with Programs. v. 34, no. 6, p. 273.
* Ivester, A.H., D. I. Godfrey-Smith, M. J. Brooks, and B. E. Taylor, 2003, "Concentric sand rims document the evolution of a Carolina bay in the Middle Coastal Plain of South Carolina". Geological Society of America Abstracts with Programs. v. 35, no. 6, pp. 169.
* Ivester, A. H., D. I. Godfrey-Smith, M. J. Brooks, and B. E. Taylor, 2004a, "The timing of Carolina Bay and inland activity on the Atlantic coastal plain of Georgia and South Carolina". Geological Society of America Abstracts with Programs. v. 36, no. 5, p. 69.
* Ivester, A. H., D. I. Godfrey-Smith, M. J. Brooks, and B. E. Taylor, 2004b, "Chronology of Carolina bay sand rims and inland dunes on the Atlantic Coastal Plain, USA". The 3rd New World Luminescence Dating Workshop. July 4 - 7, 2004, Department of Earth Science, Dalhousie University, Halifax, Nova Scotia, p. 23.
* Ivester, A. H., M. J. Brooks, B. E. Taylor, 2007, "Sedimentology and ages of Carolina Bay sand rims". Geological Society of America Abstracts with Programs. v. 39, no. 2, p. 5
* Johnson, D. W., 1942. "The Origin of the Carolina Bays". New York: Columbia University Press.
* Kaczorowski, R. T., 1977, "The Carolina Bays: a Comparison with Modern Oriented Lakes" Technical Report no. 13-CRD, Coastal research Division, Department of Geology, University of South Carolina, Columbia, South Carolina. 124 pp.
* Kobres, R. et al. (2007) "Formation of the Carolina Bays: ET Impact vs. Wind-and-Water" Eos Trans. AGU, 88(23), Jt. Assem. Suppl., Abstract PP43A-10 [http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=sm07&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=carolina%20bays&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c788%7c4554%7cFormation%20of%20the%20Carolina%20Bays:%20ET%20Impact%20vs.%20Wind-and-Water%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c5539757%205544311%20%2fdata2%2fepubs%2fwais%2fdata%2fsm07%2fsm07.txt]
* Markewich, H. W., and W. Markewich, 1994, "An overview of Pleistocene and Holocene inland dunes in Georgia and the Carolinas; morphology, distribution, age, and paleoclimate". Bulletin no. 206, United States Geological Survey, Reston, Virginia, 932 pp.
* Mixon, R. B., and O. H. Pilkey, 1976, "Reconnaissance geology of the submerged and emerged Coastal Plain province, Cape Lookout area, North Carolina". Professional Paper no. 859, U. S. Geological Survey, Reston, Virginia.
* Otvos, E. G., 1976, "Pseudokarst" and "pseudokarst terrains"; problems of terminology". Geological Society of America Bulletin, v. 87, no. 7, pp. 1021-1027.
* Prouty, W. F., 1952, "Carolina Bays and their Origin". Geological Society of America Bulletin vol. 63, no. 2, pp. 167-224.
* Rasmussen, W. C., and T. H. Slaughter, 1955, "The ground water resources, in The water resources of Somerset, Wicomico, and Worcester Counties ". Bulletin no. 16, Maryland Geological Survey, Baltimore, Maryland, 170 pp.
* Sharitz, R. R., 2003, "Carolina Bays wetlands, unique habitats of the Southwestern United States". Wetlands. v. 23, no. 3, pp. 550-562.
* Thom, B. C., 1970, "Carolina Bays in Horry and Marion County, South Carolina". Geological Society of America Bulletin. v. 81, no.3, pp. 783-814.
* Watts , W. A., 1980, "Late-Quaternary vegetation history at White Pond on the inner coastal plain of South Carolina". Quaternary Research. v. 13, no. 2, pp.187-199.
* Whitehead, D. R., 1964, "Fossil pine pollen and full-glacial vegetation in southeastern North Carolina". Ecology. v. 45, no. 4, pp. 767-777.
* Whitehead, D. R., 1967, "Studies of full-glacial vegetation and climate in the southeastern United States". in E. J. Cushing and H. E. Wright, Jr., eds, pp. 237-248. Quaternary Paleoecology. Yale University Press, New Haven, Connecticut.
* Whitehead, Donald R., 1981, "Late-Pleistocene vegetational changes in northeastern North Carolina. Ecological Monographs". v. 51, no. 4, pp. 451-471.
* Zanner, C. W., and M. S. Kuzila, 2001, "Nebraska’s Carolina bays". Geological Society of America Abstracts with Programs, v. 33, no. 6, pp. 438
* Zanner, C. W., W. Dort, Jr., and S. R. Bozarth, 2007, "Holocene Bognell Loess Chronology. Stratigraphy and paleoenvironemntal reconstructions from within a loess table, Southwestern, Nebraska". Geological Society of America Abstracts with Programs, v. 39, no. 3, pp. 73

External links

* [http://eeg.geoscienceworld.org/cgi/content/abstract/5/3/261 Factors in the Development of Carolina Bays]
* [http://www.pnas.org/cgi/content/abstract/0706977104v1 Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling]
* [http://gsa.confex.com/gsa/2002AM/finalprogram/abstract_45547.htm Age of Carolina Bays Determined by OSL Dating]
*Pinter, N., and S.E. Ishman, 2008, [http://www.gsajournals.org/archive/1052-5173/18/1/pdf/i1052-5173-18-1-37.pdf "Impacts, mega-tsunami, and other extraordinary claims" PDF version, 304 KB] . GSA Today. vol. 18, no. 1, pp. 37-38.
* [http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_64899.htm Chronological Evolution of a Carolina Bay as Indicated by OSL Dating]
* [http://gsa.confex.com/gsa/2004AM/finalprogram/abstract_78899.htm The Correlation of Carolina Bay Formation with Pleistocene Dune Activity]
* [http://gsa.confex.com/gsa/2007SE/finalprogram/abstract_119179.htm Sedimentology and Ages of Carolina Bay Sand Rims]
* [http://gsa.confex.com/gsa/2007SE/finalprogram/session_18800.htm Geology and Ecology of Carolina Bays] abstracts of 2007 Geological Society of America Meeting Carolina Bays Session
* [http://abob.libs.uga.edu/bobk/cbayint.html Analysis of Extraterrestrial Origin of Carolina Bays]
* [http://www.hallofmaat.com/modules.php?name=Articles&file=article&sid=86 Another Analysis of Age and Origin of Carolina Bays]
* [http://www.georgehoward.net/carolinabays2005.htm Aerial Photographs of Carolina Bays]
* [http://www.uga.edu/~srel/bays.htm UGA site dealing with the bays]
* [http://gsa.confex.com/gsa/2001AM/finalprogram/abstract_22324.htm Carolina Bays in Nebraska]
* [http://www.topozone.com/map.asp?z=17&n=3755308.00008197&e=590265.000000127&datum=nad83 Topozone topographic map of Woods Bay, with another adjacent bay that has been drained for agriculture]
* [http://abob.libs.uga.edu/bobk/cbayvirg.html Carolina Bays in the Upland Gravels of Midlothian, Virginia]
* [http://bbs.keyhole.com/ubb/showthreaded.php?Cat=0&Board=EarthNature&Number=367970 (Google Earth Community) The metropolitan area surrounding and including Perth, Australia, is peppered with oval landforms similar in shape to the mysterious Carolina bays of the Southeast USA.]
* [http://www.georgehoward.net/cbays.htm An essay reviewing the history of the Carolina Bay origin debate]
*Diane Tennant series, The Virginian-Pilot, September 2008
** [http://hamptonroads.com/2008/09/carolina-bays-explaining-cosmic-mystery The Carolina bays: Explaining a cosmic mystery]
** [http://hamptonroads.com/2008/09/were-carolina-bays-related-extinction-mammoth Are Carolina bays related to the extinction of the mammoth?]
** [http://hamptonroads.com/2008/09/carolina-bays-new-evidence-points-killer-comet The Carolina bays: New evidence points to a killer comet]