Are They Extraterrestrial Impact Zones, Ancient Ocean Currents, or Massive Prehistoric Alligator Holes?

Examining the Mysterious Carolina Bays

Fact or Fiction? Uncovering the origin stories of these geological anomalies.

Though they may go by different names up north, Carolina Bays dot the map in the east from New York to north Florida. They are shallow elliptical depressions in the earth, often wetlands, marshes, swamps, or lakes, named for the Bay trees that are found along their rims. North Carolina has many of these depressions and the largest forms the oldest, and biggest fresh water lake in the state, Lake Waccamaw. The origin of the Carolina Bays has long been a mystery.

Dinosaur Era Fish Spawning?

One hundred million years ago there was an ocean covering the coastal plain of the Carolinas. The Late Cretaceous period was a time of a tremendous amount of biodiversity. There were still dinosaurs, but the time of mammals had arrived. The ocean had abundant life too. Schools of fish on the scale of whales could move ocean currents with their passing. In the relatively shallow ocean above the coastal plain of the land mass that would become North America these massive schools of huge fish would swim together and procreate in a swirling sediment disturbing frenzy, circling around until they'd formed a large pond in the sandy ocean floor, where they could safely spawn. As sea levels changed the spawning grounds became inaccessible. The water receded leaving shallow, elliptical depressions behind. 

Safe Harbor for Ancient Ancestors of the Alligator? 

The sea level changes happened over time as plate tectonics gradually moved the land mass westward. Ocean life had time to adapt to these environmental changes, what happened next they did not have time to adapt to. Sixty-six million years ago, the end of the Late Cretaceous, was a terrifying time to be on earth. A massive disastrous event changed the oceans and atmosphere. Asteroid impact or volcano or both, the earth moved, tons of soot, ash, and sediment clouded the air and acidified the water. The temperature rose as the sun's heat could not escape through the cloud layer. Death and decay were everywhere. The low lying areas where there was still fresh water became vital to the life that was left. 75% of life on earth died and rotted. The only large four legged creatures to survive were ancient sea turtles and crocodillians, who kept their ectothermic bodies cool in the mud. The only dinosaurs to survive were the avian dinosaurs who could fly in search of food or water. 

Life in the Paleocene, sixty-five million years ago, was tough, but there was life. Temperatures regulated and acidity levels began to clear. Plants and animals adapted and evolved in new ways. The massive crocodillian ancestors of our american alligators survived the hard times down in the mud and they developed a unique technique to increase their availability of fresh water. They wallowed. Not just any rolling around in the mud, strategic circling to push the mud out around them, creating a small pool. These massive creatures would wallow out a space in the mud until they had their own pond. During the hundreds of years of their lives they would continue to push mud around in the bottom of their hole. Massive amounts of time pass. As the Paleocene came to an end another time of upheaval as the plate moved in a much faster way than it had before and volcanic events again raised the carbon levels in the atmosphere and raised the temperatures. Animals had to adapt again and many new species developed in the warm jungles of the Paleocene-Eocene, including primates. The earth's land was covered in plant life, the ocean had vast reefs and forests of algae. 

 More huge amounts of time passed. The abundance of plant life worked to clean the atmosphere. During the Eocene the levels of carbon in the atmosphere cleared. The earth eventually began to cool again and ice formed at the poles. Sea levels dropped and land bridges allowed the new species to travel. The first ancestors of humans evolved. Things were looking up. The cold and the low sea wasn't for everyone and there were extinctions, just not on the scale of some of the previous catastrophes. During the Oligocene the tropical forests receded to the equatorial regions and grasslands spread around the globe where there was not ice. The earth went through a series of warming and cooling. As plate shifts continued, volcanic events would increase carbon levels and temperatures would increase, as temperatures increased the plant life increased, cleaning the air and allowing for cooler temperatures. In an extended absence of any carbon increasing events, the earth cooled enough to create a series of ice ages. 

Relict Thermokarst Lakes (Glacier puddles)

Two million years ago the earth had cooled to the point of freezing. The Last Ice Age propelled a mass migration. Glaciers covered most of the northern land mass. The climate changes again increased the rate of evolution in some animal classes. Many mammals adapted with thick fur and some form of hibernation during the coldest months. The massive glacial ice sheet spread further from the poles, covering a great deal of the earth in ice. Then tens of thousands of years ago, the ice spread suddenly stopped. 

The climate began to warm again. Animals that had adapted to the cold moved further and further north, some became extinct. Equatorial animals began to spread into newly warmer regions. 

The end of the last Ice Age ushered in the Holocene, which is the geological time we are still currently experiencing.

As the ice melted left over glaciers created lakes. Depositing whatever sediment had frozen in the initial ice or had been carried along with glacial movement. Shallow elliptical ponds and lakes could be glacial remnants.  

Extraterrestrial Impact Zones

The People of the Falling Star

Ten thousand years ago people settled into a routine in the lush region that is now southeastern North Carolina. The Ice Age was over and food was no longer scarce. The people didn't have to follow herds of large animals. Instead they hunted smaller animals, gathered fruits and nuts in season, and fished on the coast. The rivers were their routes from the lush interior to the coast and this is often where they settled. The ancestors of the Waccamaw people were building a settlement in the interior along a river amongst a forest as old as time. They learned how to grow their own food. The soil in the forest was rich but there was not enough sun and too many trees and the people began to cultivate the land, taking down the trees and planting crops. They believed they had created a beautiful garden. One night as they slept in their village next to their garden, the sky lit up with a crack louder than any thunder they'd ever heard. A bright streak ran across the sky and then... Boom! Everything went silent. Then muffled screams and moans, and then men shouting, and the sound of rubble moving. Flicker of flames and choking smoke. Through the night they worked to uncover those buried and trapped and heal the hurt. At first light the scope of things came into better focus. There was dirt everywhere. Their garden, meant to feed the whole village was gone. Nothing was left but a smoldering hole. It began to rain. Mud covered everything. Water began to fill the hole. The women and children huddled together under the shelter of the trees at the edge of the village as the men worked in the rain and mud. A silver haired old woman with no teeth and a face of wrinkles came out of the woods. She had animal skins to cover the children, and a snack of blackberries and walnuts. She told them she had seen the whole thing from her spot up river. "A star fell from the sky and landed right in the middle of that enormous garden." She turned to the children and shook a crooked old finger, "you know this is because, the people forgot to be thankful. They were overlooking the gifts and abundance and destroying what is free to create a life of labor for themselves. The Creator was not happy." It would not be the last time the natural resources were abused by humans.

Who cares how it got here, lets make money!

In the mid 1600's the English King gave the Waccamaw land to a Lord as part of a large land grant, he then divided it among his heirs and others who wanted to colonize their piece of the ‘new world’. As the European invaders began settlement, the Waccamaw people retreated further into the swamps. The story historians tell involves the son of a cattle farmer from the Virginia colony who settled his grant in the 1700's and began buying up the area after the revolution. His family continued to be large landholders in the area for several generations. They were uninterested in how the lake had formed, only motivated by it's usefulness to their mercantile aspirations. For two hundred years the land was used for lumber and turpentine production. The lumber yards produced shingles from the giant cypress trees of the swamp surrounding the lake. The industry brought the railroad to the area. A depot was built in 1900. In 1926 a dam was built to prevent the lake water levels from dropping during dry weather. It was ceremoniously declared a State lake in 1929, as government interest in preserving natural resources began to increase. A YMCA boys camp was created on the banks of the lake.

A bird's eye view

With airplanes came areal photography and a renewed interest in the origin of the Carolina Bays. The extraterrestrial impact hypothesis came back with a vengeance. Truthfully the appearance from above does lend itself to this explanation. Scientists even had areal surveys commissioned, taking measurements of the angles of each ellipse. 

The Younger Dryas period is sometimes explained by the impact of material from outer space. The Carolina Bays were used as evidence of this most recent massive climate altering impact.  

The Carolina Bays and other NC wetland areas began receiving State and federal protection in the 1970's. Lake Waccamaw became a State Park. For several decades the catastrophic comet creation story was considered scientific fact.

Technology and testing today

As technology advanced, satellite imaging, core sampling, particle analysis, and radiocarbon dating disproved the theory of extraterrestrial impact. The Bays are shallow and the depression is in the superficial sandy surface, the bedrock underlying the Bays remains undisturbed.  Lake Waccamaw is located in the larger geological region known as the Pee Dee Formation, named after the river which exposed the ground underlying the area. The Pee Dee Formation is a marine deposit from the Late Cretaceous, (when the ocean covered the area). Glauconitic sand and fossiliferous limestone make up the bedrock. That means there is a dark greenish sand and  limestone rocks that contain fossils from a hundred million years ago covered in a layer of newer sediment.  Lake Waccamaw is underlain by layers containing fossils of the lower Pliocene Goose Creek Limestone and the lower Pleistocene Waccamaw Formation. The sediment layer and the underlying layer have been radiocarbon dated.  The lake is estimated to be 15,000 to 30,000 years old. In 2008 a whale fossil was found in the lake believed to be one to three million years old. All this data collection has reignited a debate about the origin of these geological anomalies. Geologists today believe terrestrial processes and repeated modification by eolian and lacustrine processes of relict thermokarst lakes created the depressions. That's geo-jargon for earth bound processes of erosion and glacier lake sediment deposits. 

The State Park

Today they offer a handful of primitive hike-in camping sites right beside the lake in the shade of the cypress trees. No frills, clean well maintained campsites for tents. There are restrooms at the visitor center.