Carolina bay
Carolina bays are oval-shaped depressions found in coastal North Carolina, South Carolina, and northeastern Georgia. Hundreds of them are present, often in groups, with alignment almost universally from northwest to southeast. Many are marshy; a few of the larger ones are (or were before drainage) lakes. Generally the southeastern end has a higher rim composed of white sand.
The bays are especially rich in biodiversity, including some rare and/or endangered species. Some have been greatly modified within human history. 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.
Woods Bay, on the Sumter-Clarenden County line near Turbeville has been designated a state park to preserve as much as possible in its natural state. Also in Clarenden County (near Manning) another bay, Bennett's Bay is a Heritage Preserve.
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 most accepted theory today is that they are impact craters created by a meteor shower. The common orientation of the bays in the same direction, and the clustering (possibly from meteors that broke up before impact) of the craters argues in favor of this point of view.
The bays are believed to be of about the same age. However, at least one very large crater that is much older has been identified at the junction of Lynches River and the Pee Dee River. Snows Island, at that point is believed to be the upthrust of the center after the impact. This eight mile wide crater is not well defined at the surface and was discovered by magnetic anomalies and confirmed by study of well drilling cores. Impact breccia was found in these cores. This crater is close to circular, not oval like the bays.
