[meteorite-list] Professor Rejects Meteor Theory of Carolina Bays' Origin

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Mar 28 16:02:18 2006
Message-ID: <200603281646.k2SGk3S29912_at_zagami.jpl.nasa.gov>

http://www.thetandd.com/articles/2006/03/28/news/doc4428a99f752a6396001544.txt

Mysterious wetlands

Citadel professor rejects meteor theory of Carolina bays' origin

By S.W. SHOPTAW
The Times and Democrat
March 28, 2006

Were they formed by the impact of a meteor striking the Earth or are
they merely sink holes? The answer to how Carolina bays were formed is
not something about which scientists agree.

Carolina bays are geological depressions of mysterious origin that occur
throughout the Coastal Plain of the Carolinas and Georgia. They take
their name from the evergreen bay trees that typically characterize them.

On March 19, Dr. Richard Porcher, a professor of biology and director of
the herbarium at The Citadel, gave a presentation on Carolina bays to
the Friends of Santee National Wildlife Refuge.

Porcher is an authority on the flora of South Carolina and the author of
"Wildflowers of the Carolina Low Country and Lower Pee Dee" and
co-author of "A Guide to the Wildflowers of South Carolina and Low
Country: The Natural Landscape."

"First described around 1750 by naturalist John Bartram, a large
concentration of Carolina bays is found in South Carolina's coastal
plain, some 4,000, but they also occur in southeastern North Carolina
and northeastern Georgia," Porcher said.

Carolina bays are isolated wetlands in natural shallow depressions,
which are largely fed by rain and shallow groundwater, he said. These
elliptical-shaped bays generally have a northwest to southeast
orientation and vary in size from less than an acre to many acres,
Porcher said. Water levels are normally lowest in autumn and highest in
early spring, he said, adding that some Carolina Bays are wet all year
while others fill with water, then dry up, depending on the season."

"Carolina bays are wetlands that are not associated with moving water.
These wetlands are rich in wildlife. I would not even begin to talk
about the wildlife, - amphibians, reptiles and other animals. That is a
whole different field," he said.

Different researchers believe Carolina bays are 30,000 to 100,000 years
old or older, Porcher said, yet scientists are not certain of their
origins. One theory suggests that a meteor hit Earth thousands of years
ago, breaking into pieces that made dents as they skipped across the
planet's surface, he said, noting that this is not a theory he accepts.

"The bays are clumped and not randomly located. I have used this against
a shower of meteorites because a shower of meteorites would seem to form
a random pattern. These bays are discretely in certain areas, and even
in a clump they seem to march in a line," Porcher said. "To me, it is
difficult to get that type of pattern from a shower of meteorites."

He said one of the features of the Carolina bays is normally that they
have a high, elevated sand ridge along their southeastern side. In
keeping with the meteorite theory, the meteorite struck and pushed out a
depression, Porcher said, and as it struck, it pushed up a sand ridge.
Some of these elevations have multiple sand ridges.

"So, if you believe a meteorite hit, you have to believe a meteorite
struck here and pushed up the first ridge. Another struck right behind
it and pushed up the second and so on," he said. "Some of these bays
have six or seven ridges."

Another theory on the creation of Carolina bays is that they were formed
over a long period of time. Some think they were formed by artisan
wells, or sink holes. However, as Porcher explained, there are "holes"
is all these theories, so the bottom line is no one theory holds water.
They are puzzling, unsolved, geological phenomena, he said.

The majority of the bays have been drained for farmland, Porcher said,
adding that there are two types of bays, a clay base and a peat base.
The clay base holds water for a longer period of time, he said, and the
plants have a period of time to establish. The peat bay has a deep layer
of peat that protects the plants and gives them water during the dry season.

Porcher led a field trip to Carolina bay near the Santee National
Wildlife Refuge. He explained that the bays have to be burned off
periodically to reduce tree growth in the bay. The last time the area
bay caught on fire, July 4, the fire was so hot and the smoke so thick
that the blaze had to be extinguished to reduce the smoke along
Interstate 95, Porcher said. This prevented the purging of the wood
growth in the bay, so the eastern portion of the bay has wood growth
along its banks.

One of the benefits of the Carolina bays is to hold water during times
of high rains, Porcher said. The bays can hold a large amount of water
and will prevent flooding along the coastlines, he said.

Currently, there is a program to restore the bays that have been damaged
by farming, Porcher said. The benefits of Carolina bays helping to
prevent flood have been recognized, he said, and efforts to restore as
many bays as possible are under way.
Received on Tue 28 Mar 2006 11:46:02 AM PST