Posted on 01/01/2009 2:09:17 PM PST by neverdem
Comet may have exploded over planet, causing fires, die-offs, researchers say
A meteorite colliding with the Earth 65 million years ago is considered to be the most likely reason dinosaurs vanished from the planet. Now a team of scientists says it has found new evidence that an object from space caused a similar extinction event only 13,000 years ago.
In an article to be published Friday in the journal Science, researchers present what one author calls the "smoking bullet"—proof that an exploding comet triggered the sudden, thousand-year freeze that killed off mammoths, saber-toothed tigers and other large mammals that used to live in North America.
Working at multiple sites across the continent, researchers found nanodiamonds—microscopic particles thought to be found on comets—in a 13,000-year-old layer of carbon-rich soil.
The authors, led by University of Oregon anthropologist Douglas Kennett, theorize that the comet exploded above the Earth's surface, raining fragments upon North America and starting fires across the continent. That would have ushered in an abrupt global cooling and caused the "megafauna" extinction.
In the layer with the nanodiamonds, fossils of the large mammals are abundant. After that layer, they disappear, said Allen West, an Arizona geophysicist and one of the paper's authors.
"It's extraordinary that tens of millions of animals disappeared synchronously at exactly the time when the diamonds and carbon layer are laid down across the continent," West said.
West said the event also would have affected human populations of the time. Artifacts from the Clovis culture of humans—an early hunter-gatherer society—also disappear after the 13,000-year layer, suggesting they, too, were killed off by the comet or its aftereffects.
Many archeologists remain skeptical of the comet theory, said Daniel Amick, an associate professor of anthropology at Loyola University Chicago who studies the Clovis culture.
"When most archeologists heard...,"
(Excerpt) Read more at chicagotribune.com ...
Thanks for posting the article.
One reason the NEAR observatories have been built all over the world.
Can aircraft trails affect climate?
Diabetes can slow the brain, study finds
FReepmail me if you want on or off my health and science ping list. Happy New Year!
Ain't every day you get one like that!
Sounds plausible to me.
Something has to explain the posies in the stomachs of the mammoths found in the ice.
And the coal found on the East coast of the US. Like a rumpled rug, the surface of the earth folded in upon itself. The surface, covered in vegetation and thick tree trunks, made the veins of coal we mine today.
Flash fire made it charcoal and then it was buried deep.
bump for later
lol...spoken as if they've never missed anything before.
Basically, that would mean one impact caused it (Ontario Impact), and one ended it (Quebec Air Blast) 2500 years later...
Yes. And a whole lot likelier than global warming from SUV's.
We'll probably get just enough warning for a quick trip to the liquor store.
I think that these events happen more often than we'd like to imagine, last one 1908.
Hey, we do the best we can. This stuff isn't as easy as it looks!
If one shows up, I hope Morgan Freeman is president rather than THE ONE.
So we have Yellowstone, and several other supervolcanoes around the world, Comets, Asteroids, lions tigers and bears oh no, and our prime worry is supposed to be non-existent AGW? LOL!
Exculpatory evidence that my ancestors were not at fault.
Only 20 days left to say “Bush’s Fault!”
I agree, tt does look good. Archaeologists and other scientists have been wondering what reversed the glacial retreat for decades.
Was it brought in by an SUV? Or did it come on its own? Or did the humans do something that did climate change?
Yup.
The early explorers/gold miners in Alaska were amazed to find what has been called “muck”.
Hard pack of mud, plant debris, and bones, mashed together and mixed up like it had gone through a cosmic blender.
More and more evidence to support the theory that there was some kind of cataclysmic event, maybe not worldwide, but a large part of it focused on northern North America, that coincided with the beginning of the end of the last ice age.
LOL
operative word, "may have"
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