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."
___
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
· join · view topics · view or post blog · bookmark · post new topic · | ||
|
|||
Gods |
Just adding to the catalog, not sending a general distribution. |
||
· Discover · Nat Geographic · Texas AM Anthro News · Yahoo Anthro & Archaeo · · The Archaeology Channel · Excerpt, or Link only? · cgk's list of ping lists · |
It seems everything is an exception
The fact remains: land animals suffered extinctions during this event at several times the rate of water animals.
Name one thing that went extinct during this event?
This so called event happened 13,000 years ago
Woolly Mammoths went extinct 11,500 years ago
Sabertooth cats went extinct 9,500
Columbia Mammoths 9,500
Megatherium 8,000
Dire Wolves 4,000
ect, ect
It looks like they are making the data fit their model just like the AGW people do.
By logic of this study, Anything that goes extinct in Siberia for the next 5000 years up until the year 6903 will be because of the Tunguska event that happened in 1903.
Wow, looks like a lot of the same wheels turning in the same ruts, again.
Some raging nimrod added “piltdownman” to the keywords.
If it makes anyone feel any better, this scenario — which involves bombardment of the Earth by various waves of particles and objects, different sizes and energies, with the waves separated by either hundreds or thousands of years, and originating in a relatively nearby star which went kaboom — is catching on some, but, as with the Alvarez model for dino extinction via an impact at the K-T boundary, has met with furious resistance.
Not Chicago, Mistassini Quebec.
PS: Part of Hudson Bay is a pretty large crater too...
Lake Mistassini might be a remnant of the comet impact (including the large depression to the southeast)
How many galaxies could Moses see?
The babble generated by your self-imposed ignorance is astounding. Are you even aware of the wealth of on-the surface Mars photos that have been generated and returned to Earth by the Mars Rovers over the past five years?
Where’s the water?
But since there is no faith, and people need to see before they believe
http://www.creationscience.com/onlinebook/index.html
Check it out, you might learn something
Check this out, you might learn something
Answer my question in #86 — and, then, I will address yours...
Moses who? Is he a scientist or something?
It's "studies" like this that give Creationist ammo against all science
You would think the authors would have at the very least check when exactly these animals actually went extinct before proclaiming that a comet wiped them out 1000's of years before they really did die out.
If it makes anyone feel any better, this scenario which involves bombardment of the Earth by various waves of particles and objects, different sizes and energies, with the waves separated by either hundreds or thousands of years, and originating in a relatively nearby star which went kaboom
More and more Epicycles!!!!!!!!!
is catching on some, but, as with the Alvarez model for dino extinction via an impact at the K-T boundary, has met with furious resistance.
Megafaunal extinctions followed human arrival in Australia, North America, New Guinea, Madagascar and South America.
Now which makes more sense?
A) Human predation and maybe diseases slowly drove these species to extinction
or
B) Coincidentally, where ever humans arrived, comets/asteroids then began to hit where these new humans were and over 100 to 1000s of years they bombarded the area, leaving no trace, but they somehow killed one or two species off at a time (while apparently leaving the others unscathed) until they were all gone.
I really don't expect you to be intelligent (or intellectually honest) enough to answer mine satisfactorily...
Nothing good comes out of Chicago, even then.
“Women and minorities hardest hit.”
What about the children?
http://www.creationscience.com/onlinebook/index.html
I am already familiar with Brown's book, and have researched parts of it many times. It is a loose-knit collection of nonsense that satisfies only those who either know nothing or are already believers. Scientific evidence it is not.
Here is one example that I have researched. He says:
This new atomic accelerator technique has consistently detected at least small amounts of carbon-14 in every organic specimeneven materials that evolutionists claim are millions of years old, such as coal. This small, consistent amount is found so often among various specimens that contamination can probably be ruled out. Ancient human skeletons, when dated by this new accelerator mass spectrometer technique, give surprisingly recent dates. In one study of eleven sets of ancient human bones, all were dated at about 5,000 radiocarbon years or less!
This is clearly wrong. I have the study he is referring to in my office (Taylor et al. 1985).
The Taylor et al. study examined eleven skeletons that were claimed to have some antiquity, up to 70,000 years, on the basis of an experimental dating technique called amino acid racemization (AAR). Those old dates did not fit the archaeological context (most samples were from Southern California). What Taylor did was reexamine those skeletons with a new form of radiocarbon dating called accellerator mass spectrometry (AMS). He found that they weren't ancient at all; none dated older than 11,000 years. That fit the archaeological context and exposed the inaccuracies in AAR.
When Brown makes a big deal about the "residual" carbon 14 in these "ancient" skeletons he makes a fundamental error: the skeletons aren't really ancient! And the study he (sometimes) cites shows it! Whoops!
Nowhere does this study cast doubt on the accuracy of radiocarbon dating. Rather Brown's use of this study in this way casts doubt on the accuracy of his research. And this error has been in his various editions since at least 1989.
Another error: the Calaveras skull. No serious archaeologist considers this to be ancient. Flowstone can be pretty quick moving in an active cave. When Brown claims this skull was "130 feet below ground" he neglects to mention it was found in a limestone cavern, and not under 130 feet of rock. Whoops!
Sorry, I'm not impressed by Brown's book, nor by the quality of his research.
Care to try again?
Thanks for the ping. The carbon layer is a very interesting find. It is evidence of massive incineration covering a large area of North America. That it was caused by the atmospheric explosion of a comet or asteroid is a reasonable theory.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.