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Did A Comet Hit Great Lakes Region 12,900 Years Ago?
05/23/2007
From
http://www.sciencedaily.com
Science Daily — Two University of Oregon
researchers are on a multi-institutional 26-member team proposing a
startling new theory: that an extraterrestrial impact, possibly a
comet, set off a 1,000-year-long cold spell and wiped out or
fragmented the prehistoric Clovis culture and a variety of animal
genera across North America almost 13,000 years ago.
Driving the theory is a carbon-rich layer of soil that has been
found, but not definitively explained, at some 50 Clovis-age sites
in North America that date to the onset of a cooling period known as
the Younger Dryas Event. The sites include several on the Channel
Island off California where UO archaeologists Douglas J. Kennett and
Jon M. Erlandson have conducted research.
The theory is being discussed publicly, for the first time, in a
news conference at the 2007 Joint Assembly of the American
Geophysical Union being held in Acapulco, Mexico. Kennett is among
the attendees who will be available to discuss the theory with their
peers. The British journal Nature addressed the theory in a
news-section story in its May 18 issue.
Before today, members of the team -- including Kennett's father,
James P. Kennett of the University of California, Santa Barbara, and
Richard B. Firestone of Lawrence Berkeley National Laboratory -- had
been quietly introducing the theory to their professional
colleagues.
Douglas Kennett, with Erlandson watching, detailed the theory May 19
to a fully packed UO classroom, where students and faculty members
from archaeology, art history, anthropology, biology, geology,
geography, political science and psychology, pelted Kennett with
questions.
The researchers propose that a known reversal in the world's ocean
currents and associated rapid global cooling, which some scientists
blame for the extinction of multiple species of animals and the end
of the Clovis Period, was itself the result of a bigger event. While
generally accepted theory says glacial melting from the North
American interior caused the shift in currents, the new proposal
points to a large extraterrestrial object exploding above or even
into the Laurentide Ice Sheet north of the Great Lakes.
"Highest concentrations of extraterrestrial impact materials occur
in the Great Lakes area and spread out from there," Kennett said.
"It would have had major effects on humans. Immediate effects would
have been in the North and East, producing shockwaves, heat,
flooding, wildfires, and a reduction and fragmentation of the human
population."
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