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Scientists say comet killed off mammoths, saber-toothed tigers
www.physorg.com ^ | 02 JAN 2009 | By Robert Mitchum

Posted on 01/02/2009 7:44:26 AM PST by Red Badger

First an explosion as powerful as thousands of megatons of TNT rained meteorites down on North America. Then forest fires broke out across the continent, sending up a thick layer of soot and dust that blocked out the sun. A sudden ice age ensued, and some of the Earth's largest animals went extinct in a blink of geological time.

It's well known that a meteorite colliding with Earth is considered the most likely reason dinosaurs died off 65 million years ago. Now a team of scientists says it has found new evidence that a comet triggered a similar extinction much more recently: just 13,000 years ago, when humans were around to witness the event and suffer its terrible consequences.

The researchers also think that when the comet exploded above the planet's surface - ultimately killing off mammoths, saber-toothed tigers and other large mammals that roamed North America - Chicago wasn't too far from ground zero.

"If you'd been in Chicago back in that time, it would've been one very bad day," said Allen West, an Arizona geophysicist and one of the authors of a paper appearing Friday in the journal Science.

The scientists, led by University of Oregon anthropologist Douglas Kennett, say their report offers up a "smoking bullet" - proof it was a comet that set off the sudden, thousand-year freeze and wiped out the big animals of the era.

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 rich sedimentary soil called a "black mat." Beneath the layer with the nanodiamonds, fossils of the animals are abundant. After that layer, they disappear, West said.

"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," said West, whose co-authors include DePaul University chemist Wendy Wolbach.

Arrowheads and other artifacts from the Clovis culture of humans - an early hunter-gatherer society - also vanish after the black mat was laid down 13,000 years ago.

In 2007, West and a team of scientists published an analysis of black mats from several regions that found heavy metals, soot and charcoal suggestive of meteorite impacts and subsequent fires. The new report says the discovery of nanodiamonds in the same material is more evidence of a cosmic strike.

Archeologists have long speculated about whether climate change or over-hunting drove the mammoths, tigers and other "megafauna" to extinction and led to the decline of the Clovis culture.

Many remain skeptical of the comet theory and think there may be better explanations for what happened, said Daniel Amick, an associate professor of anthropology at Loyola University who studies the Clovis culture.

"When most archeologists heard about it they were somewhat dismissive," Amick said. "We would think, 'How in the world could we have missed this? How could this spectacular kind of event have occurred and never even dawned on us?'"

The authors have much to prove before their theory is accepted, Amick said, like pinpointing the date of the event and ruling out other potential causes of extinction and climate change.

In response to one common criticism of the comet theory - that no craters have been found from an impact - West said the comet may not have actually reached Earth, but exploded into fragments somewhere above the surface.

Where exactly that might have happened is a mystery, but high concentrations of nanodiamonds at a site in Eastern Michigan suggest the Great Lakes as a possibility.

"We think that Chicago might well have been very near ground zero," West said.

The idea that a comet may have caused catastrophic climate change and extinction relatively recently in Earth's long history suggests scientists shouldn't dismiss the possibility of it happening again, Wolbach said.

"Should we be doing more to try to deflect future asteroids, or is that too sci-fi?" she said. "If this is true and there was an impact 12.9 thousand years ago, obviously this is not something that's just a theoretical idea, it's a real thing."

___


TOPICS: Canada; Culture/Society; Miscellaneous; News/Current Events
KEYWORDS: catastrophism; climatechange; crevo; dinosaurs; globullwarming; godsgravesglyphs; piltdownman; space
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To: Cheesel

There are large craters all over the world, even Europe............


61 posted on 01/02/2009 8:41:14 AM PST by Red Badger (I was sad because I had no shoes to throw, until I met a reporter who had no feet.....)
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To: onedoug

Because this is L.A., not Chicago, and we don’t care how they do it in Chicago!


62 posted on 01/02/2009 8:43:29 AM PST by count-your-change (You don't have be brilliant, not being stupid is enough.)
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To: kidd

Thanks, I couldn’t have said it better, I agree with you completely, and that means most of what everyone hears today is this bad science, and I mean really bad, it doesn’t even qualify as science, and that includes what we hear coming out of the space program unfortunately.


63 posted on 01/02/2009 8:47:01 AM PST by Scythian
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To: Red Badger; zot
This article is vague on how a comet could cause continent-wide fires. The answer is that air heats dramatically when compressed. The overpressure shock wave from such an event would have incinerated people, animals and vegetation over a huge area. That would explain why the Pliestocene extinction rate was much higher among land animals than for those that lived in the water.
64 posted on 01/02/2009 9:03:47 AM PST by Interesting Times (For the truth about "swift boating" see ToSetTheRecordStraight.com)
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To: qam1

“Plus it’s amazing how Alligators are always near ground zero for these Asteroid/Comet hits, yet they always manage to survive unscathed.”

4 functioning brain cells, a bullet-proof hide and that smile they wear no matter what’s going on.


65 posted on 01/02/2009 9:12:31 AM PST by TalBlack
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To: Scythian

Amen to that. If you cannot prove it, it’s not science just supposition.


66 posted on 01/02/2009 9:15:08 AM PST by Centurion2000 (To protect and defend ... against all enemies, foreign and domestic .... by any means necessary.)
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To: gimme1ibertee

“....orange tabby...”

I have one named Norman. Same thing with him; lives with 2 pit bulls and thinks he’s one. He CANNOT be left home when we walk the dogs and runs out of the house to see other dogs walking down the street w/ their owners.

LOL

meaner n’ a snake but also VERY sweet! heehee


67 posted on 01/02/2009 9:16:28 AM PST by spacejunkie01
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To: Red Badger
One of these days, the "scientific community" is going to have to admit that Immanuel Velikovsky was correct and that within historical times (he said approximately 1500BC) Venus was a comet that a) interacted with Mars and b) made a "swipe" at the earth that nearly destroyed civilization.

Next time you see a Chinese Dragon look for the ball close to it. It is usually red or gold and smoking. That would be Mars.

Velikovsky's books are out of print, but you can still find used copies. I liked "Earth in Upheaval" best. He talked about the three meters of "muck" which was jumbled tropical plant and animal remains that had to be dug through to get to the gold in Alaska. Funny how I haven't heard about that anywhere else.

And Herodotus said that the Egyptians said that during their history the sun had changed its direction of travel three times. He wrote is if he didn't believe them. But why would someone lie about something like that?

What is interesting about all of this is that if catastrophies occur on a regular basis, then mankind is NOT IN CONTROL OF ITS DESTINY. This is anathema to liberals, socialists, communists and that ilk.

68 posted on 01/02/2009 9:19:28 AM PST by Lafayette (You would think that Patrick Henry said, "Give me DEMOCRACY or give me death!")
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To: Interesting Times
That would explain why the Pliestocene extinction rate was much higher among land animals than for those that lived in the water.

Sure.. Like the aquatic American Bison that survived

Or the Land Loving Giant Beaver that went extinct

Sorry, I think what Geologist Norman Macleod said about the Dino Asteroid hypothesis

"The impact theory says in effect that a rock fell out of the sky and killed everything, except for the things that it didn't kill. I don't think that's much of an explanation."

Fits here as well

69 posted on 01/02/2009 9:26:12 AM PST by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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To: count-your-change

I’d say then, that this “theory” is full of holes.


70 posted on 01/02/2009 9:31:20 AM PST by onedoug
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To: qam1

It’s no great feat to find a couple of exceptions.

The fact remains: land animals suffered extinctions during this event at several times the rate of water animals.


71 posted on 01/02/2009 9:32:00 AM PST by Interesting Times (For the truth about "swift boating" see ToSetTheRecordStraight.com)
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To: onedoug
Yes, It's also known as the Limburger/Swiss Theory, full of
holes, stinks and is a bit cheesy.
72 posted on 01/02/2009 9:45:56 AM PST by count-your-change (You don't have be brilliant, not being stupid is enough.)
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To: Scythian
This stuff is such hogwash, honestly, science is nothing but fairy tales these days, in search of either grants to futher their worthless careers or to carry the mantle of thier twisted ideology.

Go back to your cave and scratch on the walls.

Or better yet, just try to invent all of the wonders of our civilization without scientists and see how far you get.

73 posted on 01/02/2009 9:53:47 AM PST by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: pctech
The world continues to find every reason under the sun EXCEPT for the Flood in Noah’s days to explain why the animals all died off.

The "global" flood was shown to be a myth 200 years ago.

74 posted on 01/02/2009 9:54:39 AM PST by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: ryan71
Scientists proving once more, they don’t know sh*t.

And you have shown you are both ignorant and arrogant.

I know a couple of those authors professionally; they are quite knowledgeable.

75 posted on 01/02/2009 9:56:29 AM PST by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Red Badger
Was that the year the Blackhawks beat the Canadians?
76 posted on 01/02/2009 10:01:24 AM PST by PSYCHO-FREEP (WHAT? Where did my tag line go?)
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To: Centurion2000
Amen to that. If you cannot prove it, it’s not science just supposition.

Science works with evidence, not proof. Here are a couple of definitions (from a long list on my FR home page) that might help:

Proof: Except for math and geometry, there is little that is actually proved. Even well-established scientific theories can't be conclusively proved, because--at least in principle--a counter-example might be discovered. Scientific theories are always accepted provisionally, and are regarded as reliable only because they are supported (not proved) by the verifiable facts they purport to explain and by the predictions which they successfully make. All scientific theories are subject to revision (or even rejection) if new data are discovered which necessitates this.

Proof: A term from logic and mathematics describing an argument from premise to conclusion using strictly logical principles. In mathematics, theorems or propositions are established by logical arguments from a set of axioms, the process of establishing a theorem being called a proof.

The colloquial meaning of "proof" causes lots of problems in physics discussion and is best avoided. Since mathematics is such an important part of physics, the mathematician's meaning of proof should be the only one we use. Also, we often ask students in upper level courses to do proofs of certain theorems of mathematical physics, and we are not asking for experimental demonstration!

So, in a laboratory report, we should not say "We proved Newton's law" Rather say, "Today we demonstrated (or verified) the validity of Newton's law in the particular case of..." Source


77 posted on 01/02/2009 10:02:15 AM PST by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Red Badger
See post #40 on this thread.
78 posted on 01/02/2009 10:53:54 AM PST by blam
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To: onedoug
...a similar extinction much more recently: just 13,000 years ago....

Then how come there were mammoths, sabertooths and humans in Los Angeles some 9,000 years ago?

The Columbian Mammoth
The Columbian Mammoth was one of the last members of the American Megafauna to become extinct, with several specimens dating to 9,000 years ago or less and one near Nashville, Tennessee, reliably dated to only about 7,800 years ago.

This study is laughable, it's a Liberal's wet dream

It's

1) Anti-Nuclear
2) Pro-AGW
3) Pro-Noble Savage

79 posted on 01/02/2009 11:14:16 AM PST by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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Scientists find signs of 13,000-year-old extinction event
Chicago Tribune | January 2, 2009 | Robert Mitchum
Posted on 01/01/2009 2:09:17 PM PST by neverdem
http://www.freerepublic.com/focus/f-news/2157352/posts


80 posted on 01/02/2009 11:24:51 AM PST by SunkenCiv (https://secure.freerepublic.com/donate/_______Profile finally updated Saturday, December 6, 2008 !!!)
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