THE CAROLINA BAYS

                                                 C A R O L I N A   B A Y S





The 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).

They are also 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).