Prehistoric humans not wiped out by comet, say researchers

Jan 30, 2013
Clovis.

(Phys.org)—Comet explosions did not end the prehistoric human culture, known as Clovis, in North America 13,000 years ago, according to research published in the journal Geophysical Monograph Series.

Researchers from Royal Holloway university, together with Sandia National Laboratories and 13 other universities across the United States and Europe, have found evidence which rebuts the belief that a large impact or airburst caused a significant and to the Earth's climate and terminated the . They argue that other explanations must be found for the apparent disappearance.

Clovis is the name archaeologists have given to the earliest well-established human culture in the North American continent. It is named after the town in New Mexico, where distinct stone tools were found in the 1920s and 1930s.

Researchers argue that no appropriately sized from that time period have been discovered, and no shocked material or any other features of impact have been found in sediments. They also found that samples presented in support of the were contaminated with modern material and that no can support the theory.

"The theory has reached zombie status," said Professor Andrew Scott from the Department of Earth Sciences at Royal Holloway. "Whenever we are able to show flaws and think it is dead, it reappears with new, equally unsatisfactory, arguments.

"Hopefully new versions of the theory will be more carefully examined before they are published."

Explore further: Lava from Hawaii volcano picks up speed

More information: Boslough, M., et al.(editors) Climates Landscapes and Civilizations. Geophysical Monograph Series, VOL. 198, PP. 13-26, 2012 (first available in January 2013).

Related Stories

Recommended for you

Icelandic volcano sits on massive magma hot spot

Oct 24, 2014

Spectacular eruptions at Bárðarbunga volcano in central Iceland have been spewing lava continuously since Aug. 31. Massive amounts of erupting lava are connected to the destruction of supercontinents and ...

NASA sees Tropical Storm Ana still vigorous

Oct 24, 2014

NASA's TRMM satellite saw that Tropical Storm Ana was still generating moderate rainfall is it pulled away from Hawaii. The next day, NASA's Aqua satellite saw that wind shear was having an effect on the ...

User comments : 47

Adjust slider to filter visible comments by rank

Display comments: newest first

antigoracle
1.7 / 5 (11) Jan 30, 2013
Must have been Global Warming.
Claudius
1.4 / 5 (10) Jan 30, 2013
The theory has reached zombie status ...Whenever we are able to show flaws and think it is dead, it reappears with new, equally unsatisfactory, arguments.


Sounds just like AGW to me, too.
Jonseer
4.2 / 5 (10) Jan 30, 2013
The theory has reached zombie status ...Whenever we are able to show flaws and think it is dead, it reappears with new, equally unsatisfactory, arguments.


Sounds just like AGW to me, too.
yes except for the tiny bit about any denialists demonstrating scientifically valid flaws in the theory as it stands and demonstrates itself as we watch.

Of course to understand what "scientifically valid" requires not only understanding but accepting the logic and reason the underlying principles of science research.

To date denialists haven't demonstrated that at all.

Perhaps it's, because most don't know what the threshold of proof is vs a vs speculation and hunches, and fall easy prey to stupid beliefs rooted in ignorance of the above.
h20dr
1.1 / 5 (8) Jan 30, 2013
The great flood.
Whydening Gyre
1 / 5 (7) Jan 30, 2013
If the comet wiped out more than half the Clovis, then the remaining didn't have the manpower to overcome any other difficulties caused either by natural phenomenon or other humans. Like dinosaurs, it was more likely a one, two, three punch.
R_R
1.3 / 5 (12) Jan 31, 2013
"Comet explosions did not end the prehistoric human culture, known as Clovis, in North America 13,000 years ago"

Oh yes they fukin did! This is just another bought and paid for attempt to cover up the truth of these matters, I suspect the goal to discredit the impact hypothesis was set out before dollar one of funding was spent.
R_R
1.3 / 5 (12) Jan 31, 2013
"Researchers argue that no appropriately sized impact craters from that time period have been discovered, and no shocked material or any other features of impact have been found in sediments"

The craters are right there in front of us such as at lower right Hudsonbay. These traitors to science spent millions but not dollar one investigating this perfect crater formation (not by accident). Perfect circular shape, perfect outer rim, perfect central uplift.......and not dollar one (and you watch, they never will spend dollar one).

There is no way in the world this perfect crater formation survived under miles of moving ice for millions of years of thier so called ice age (Pole shift cover up). All the evidence this is a very recent crater is right there if science spent just a few dollars to investigate but its never going to happen. There is no shocked material because all the material was driven into the core when this impacter pierced the continent. The craters exist all right!
R_R
1.3 / 5 (12) Jan 31, 2013
"The theory has reached zombie status," said Professor Andrew Scott from the Department of Earth Sciences at Royal Holloway."

This head *puppet* is using a psychological technic to try and get fellow scientists to shy away from this subject for fear of ridicule and retribution. Andrew Scott of Fringe Sciences of Royal Holloway only wants to turn you Zombie! The impact evidence is waistdeep everywhere if we take our blinders off, from eratic boulders to carolina bays to continental mega floods. This is why the ice disappeared from North America, the Clovis people vanished and half the mega mammals went extinct.......
Sinister1811
3.7 / 5 (12) Jan 31, 2013
The theory has reached zombie status ...Whenever we are able to show flaws and think it is dead, it reappears with new, equally unsatisfactory, arguments.


Sounds just like AGW to me, too.


I'm assuming you guys have an alternative explanation for the modern shift in climatic trends, which is consistent with a rising concentration of atmospheric CO2? You can't continue to live that way - you're going to have to take your heads out of the sand sooner or later.
Maggnus
3.5 / 5 (8) Feb 01, 2013
Oh yes they fukin did! This is just another bought and paid for attempt to cover up the truth of these matters, I suspect the goal to discredit the impact hypothesis was set out before dollar one of funding was spent.


Wow RR you're trying hard to use some real loaded phrases to strike up a debate. So how about, instead of screaming loudly about how hard done by you are, you spend a little bit of time to set out your evidence supporting your assertation that the Clovis civilization was driven to extinction by a comet?

Try to avoid using phrases like "all science is against me" or "people would see if they would only listen to me" and focus instaed on the evidence.
R_R
1.4 / 5 (9) Feb 01, 2013
Maggnus says "Wow RR you're trying hard to use some real loaded phrases to strike up a debate"

I'm trying hard to show people the truth, and certainly not interested in your kind of personal attack debate, the same kind that has been succesful for 60 years in covering up the truth since Mr. Hapgood correctly showed the Pole was at Hudsonbay 12,000 years ago. Debate is pointless with your kind although you are a case study on why these outrageous lies manage to go on and on.
R_R
1.4 / 5 (9) Feb 01, 2013
Maggnus, Your so called debate starts like this "instead of screaming loudly about how hard done by you are, you spend a little bit of time to set out your evidence"

I dont feel hard done by at all, thats just your poorly masked attempt to confuse the issue. I clearly stated some of my evidence such as eratic boulders are actually blast debri and I clearly presented one of the craters was at Hudsonbay and bagan to show why, but your not interested and never a question will emerge from your mouth. Play your childish game elsewhere.

Maggnus
3 / 5 (6) Feb 01, 2013
Typical rant there RR. So lets try using a little more science and a little less schilling shall we?
The craters are right there in front of us such as at lower right Hudsonbay.

Hudson's Bay is very large, and the "lower right" of it is a very imprecise location. Can you be a little more specific?
There is no way in the world this perfect crater formation survived under miles of moving ice for millions of years of thier so called ice age (Pole shift cover up).

That's quite a jumble of information! So if I follow you correctly, you are suggesting that the scientists who suggest there was an ice age are wrong? Or are you suggesting that ice cover in Northern Canada arose because the pole was somehow shifted?
The impact evidence is waistdeep everywhere if we take our blinders off, from eratic boulders to carolina bays to continental mega floods.

Waist deep! That's alot! So I'm trying t remove my blinders here. Where are these "eratic" boulders exactly? .
R_R
1.4 / 5 (9) Feb 01, 2013
"Typical rant there RR."

Back at ya

"So lets try using a little more science"

This science is nothing but a giant house of mirrors, each mirror being an assumption.

The craters are right there in front of us such as at lower right Hudsonbay.

"Hudson's Bay is very large, and the "lower right" of it is a very imprecise location. Can you be a little more specific?"

The lower right is nothing but a giant 500 KM wide perfect circular crater, do you need glasses?
R_R
1.4 / 5 (9) Feb 01, 2013
"So if I follow you correctly, you are suggesting that the scientists who suggest there was an ice age are wrong?"

No I'm not suggesting, suggesting has got us nowhere up against the billion dollar lie machine. Read the article above again to start to get an idea of the forces we up against. And contemplate THE TITLE carefully, it spells out the agenda.

"Or are you suggesting that ice cover in Northern Canada arose because the pole was somehow shifted?"

The ice cover on North America was a normal ice cap centered on Hudsonbay for millions of years, marking the position of earths north pole pre 10500 BC. Pole Shift to its present position left this area at a southern latitute were by the ice melted away.

"Waist deep! That's alot! So I'm trying to remove my blinders here. Where are these "eratic" boulders exactly?

Google eratic boulders, just ignore the bullshit that moving ice positioned them.
Maggnus
3 / 5 (6) Feb 01, 2013
Ya ok, so you ARE just an ignorant troll. I thought as much, but I do try to give the benefit of the doubt.
R_R
1.5 / 5 (8) Feb 01, 2013
You had no one fooled sheepboy
Maggnus
3 / 5 (6) Feb 01, 2013
**Yawn** Ok whatever you say trollboy. Careful your tinfoil hat has slipped a bit.
Maggnus
3.4 / 5 (5) Feb 01, 2013
Anyway, ignoring psychotroll's incoherent ranting, I wonder what theories remain to explain the sudden loss of large mammals in NA 12,000 or so years ago. I saw a suggestion that there may have been a volcanic origin to the extinctions, and I wonder if that has any traction as an explanation?
jsdarkdestruction
4.3 / 5 (7) Feb 02, 2013
R_R, the pole shifting impact that stopped and reversed the earths rotation you speak of would of killed everything on the planet except maybe some extremophiles. this has been pointed out to you again and again and again. why dont you join reality?
R_R
1.5 / 5 (8) Feb 02, 2013
Dark, Certainly we were nearly wiped out but dont believe me. Genetic studies should show there was a bottleneck back in time and every one on this planet today is descendent from just a few thousand people say. Perhaps you or someone can shed more light on this.

North America was not the place to be though, the Clovis people and basically every other creature just up and vanished. How does your reality explian that?
Maggnus
3 / 5 (8) Feb 02, 2013
but dont believe me.


No worries, we don't. And now, to reality...

The volcanic explanation doesn't work either, the fossils I was thinking of that were recovered from a volcanic ash filled pit were dated to the last yellowstone eruption.

I tend to agree with Graysom & Meltzer (Journal of World Prehistory, Vol. 16, No. 4, December 2002) that the cause was probably not overhunting, whic I guess leaves pretty much climate change as the leading candidate (well ignoring psychotroll's poleshift BS).

Kind of ironic considering the first two posts lol.
Maggnus
3 / 5 (6) Feb 02, 2013
Genetic studies should show there was a bottleneck back in time and every one on this planet today is descendent from just a few thousand people say. Perhaps you or someone can shed more light on this.


Well this is true, except that the bottleneck has been traced back to ~74,000 YA, and corresponds to the mega-volcanic eruption of Toga. Its been estimated that the human race was reduced to as little as 5000 individuals a a result of that eruption.
R_R
1.4 / 5 (9) Feb 02, 2013
Maggnus, there in your answer lies the problem, nowhere in that thick head of yours is there space for the thought that just maybe science has the date of the bottle neck wrong, just maybe that bottle neck coincides with one of the largest exctinction events in earths history, the ice age extiction of 12,000 years ago. It wont matter to you that the 74,000 YA date is based on giant assumptions because your arogence will always trump common sense.
Maggnus
3.9 / 5 (7) Feb 02, 2013
@ RR Wow you're really a dummy hey? Been spending too much time at the shallow end of the gene pool have we? Largest extinction event in Earth's history you say? The Toga eruption is based on a giant assumption is it? Wow please do enlighten us further!
RealScience
5 / 5 (6) Feb 02, 2013
@R_R - if anything had punched a hundreds-of-km hole in the crust only 12,000 years ago the area would still be very hot a kilometer under the surface and would show up like a beacon in seismic data.
Please learn about thermal conductivity as well as kinetic energy and momentum.

@Maggnus - R_R is referring to the Nastapoka Arc, a well known feature that once was accepted as >1 billion-year-old impact crater. An expedition in 1972 found no impact evidence, but other theories aren't convincing either.

However I'd keep an open mind on an impact as a cause of the Younger Dryas and the Clovis disappearance. Quite a few reputable scientists have found evidence FOR an impact, so even a top scientist finding one set of evidence to be contaminated is far from conclusive. Similar debates over impact evidence occurred regarding the demise of the dinosaurs, and while even that isn't completely settled the preponderance of the current evidence there is for a massive impact being involved.
RealScience
5 / 5 (8) Feb 02, 2013
-Continued-
But it certainly wasn't a pole-shifting impact as R_R proposes. That would have wiped out humanity and left unmistakable signs.

Impact: Perhaps another 20 years of evidence gathering will settle it.
Pole-shifting impact: No way.
Maggnus
3.4 / 5 (5) Feb 02, 2013
@RealScience: Well you assume he means the Nastapoka Arc. He didn't say that. Still, good call. I just didn't think that someone could suggest a 280KM wide crater could have occurred only 12,000 years ago!

More importantly (given psychotroll has no clue what he is talking about, so his input is irrelevent) I don't dismiss out of hand an astronomical cause of the Clovis extinction, as I am not satisfied wth any other explanation either. I suggest a number of factors combined to drive the extinction. However, no matter how satisfying that explanation is to me personally, it remains the case that the cause has not been firmly established one way or the other. Definately more evidence gathering is needed.
R_R
1.4 / 5 (9) Feb 03, 2013
"no way"

Real, the idea that mile thick ice sheets could reach 3500 miles from the pole into the USA on one side of the planet while only 1000 miles from the pole on the other side of the planet in Siberia millions of mammals would be grazing the ice free shores of the arctic ocean is most rediculus bizzar far side twilight zone gaff of nonsense known to man. Ice behaved then just as it does now in Antarctica, growing outward roughly equal distance from the pole in all directions, not some fantasy super lobe covering Australia. Youve been duped sir, the poles did shift, *way*
StEngela
3.8 / 5 (4) Feb 03, 2013
If there was an ice age, and the comet impacted into miles-thick ice, could that explain the lack of cratering?
Maggnus
3 / 5 (4) Feb 03, 2013
If there was an ice age, and the comet impacted into miles-thick ice, could that explain the lack of cratering?


Possibly. The problem is the scale of the extinction; it appears to have be continent wide. An impact large enough to do that should have left some sign.
StEngela
3.2 / 5 (5) Feb 04, 2013
Possibly. The problem is the scale of the extinction; it appears to have be continent wide. An impact large enough to do that should have left some sign.


Well, there are the Great Lakes and, even better, the Hudson Bay. Either of which a continent wide extinction level event could occur without leaving much in the way of cratering. However, if you look at a map of Hudson Bay, there are some peculiarly circular features to its southwestern shoreline.
Maggnus
3 / 5 (4) Feb 04, 2013
@ StEngela - Are you suggesting the Great Lakes are an impact site? Can you be more specific regarding where you think there are circular features? Hudson's Bay is huge so just saying the southwestern shoreline is not much help.

When you're looking for an impact site, keep in mind that the Chicxulob crater is about 110 miles in diameter, and that was enough to wipe out 70% of life on the planet.

I am not necessarily looking for an impact crater here. Rather, there should be other evidence that covers a large enough area to have impacted species over the whole continent. Bolides, shocked soils/rocks, impact breccia, soot, that type of evidence.
R_R
1 / 5 (6) Feb 04, 2013
"Well, there are the Great Lakes"

Good one, You couldn't get a better example of a horseshoe crater.
StEngela
1 / 5 (3) Feb 05, 2013
Re: Hudson Bay. Go to your preferred mapping website. Zoom out to find Polar Bear Provincial Park in the northeast of Ontario. Across the bay, to the northeast, there is what looks like to me an impact crater. If that area was covered at the time by ICE, lots and lots of ice, the ice would've vaporised. Having not hit a regular land mass, and maybe not being as big as Chixulub, your missing bolides, shocked rock/soil, etc., might not have happened. Maybe someone should go up there and take a look. Just saying.
StEngela
1 / 5 (4) Feb 05, 2013
Re: Hudson Bay Impact Crater: Latitude 56°11'6.93"N, Longitude 79°28'17.95"W. It's even clearer that Chixulub.
R_R
1 / 5 (6) Feb 12, 2013
You nailed it StEngela, how obvious a crater do they want. The only thing in nature that produces such a perfect circular formation is an impact and it even has the tell tale central uplift, the Belcher Islands. And its almost certainly a post "ice age" crater, given its pristine condition.

Yet from the article

"Researchers from Royal Holloway university, together with Sandia National Laboratories and 13 other universities across the United States and Europe......argue that no appropriately sized impact craters from that time period have been discovered"

So is this about finding the answers or about covering them up?
Maggnus
3 / 5 (4) Feb 12, 2013
Physcotroll has returned I see. Out for your morning troll run are we?

@StEngela: Might be, might not be. I can find nothing easily to say one way or the other. Certainly, just the fact of a roundish formation is not enough to say an impact crater. There needs to be evidence of impact; meaning shocked rock, impact breccia, etc.

Remember too, a large impact leaves LOTS of evidence, not just a crater. The whole point of this article is that there is a dearth of evidence supporting even an airburst. My question remains: if not an impact, what?
R_R
1 / 5 (6) Feb 12, 2013
Thanks Maggnus for setting us straight, what ah inspiring intellect, we bow and await your ruling.
Maggnus
3.4 / 5 (5) Feb 12, 2013
Thanks Maggnus for setting us straight, what ah inspiring intellect, we bow and await your ruling.


You're welcome! :) Please, no need to bow, I'm blushing!

Instead, I am happy if you just take the time to read and learn a little about the damage that an impactor can do to the planet. It's really interesting stuff!

And no ruling from me, I'm definately not qualified for that!
barakn
3 / 5 (2) Feb 13, 2013
the idea that mile thick ice sheets could reach 3500 miles from the pole into the USA on one side of the planet while only 1000 miles from the pole on the other side of the planet in Siberia millions of mammals would be grazing the ice free shores of the arctic ocean is most rediculus bizzar far side twilight zone gaff of nonsense known to man. Ice behaved then just as it does now in Antarctica, growing outward... -R_R
If only we had some other examples of ice caps.... Oh, wait, we do. Greenland is the greatest vestige of the ice age ice in the Northern hemisphere. And yet we find - at the same latitude as Greenland ice - permanently populated cities like Reykjavik, Arkhangelsk, and Fairbanks. Obviously the current polar ice is not symmetrical with respect to the Earth's rotational axis, so your insistence that it had to be so in the past is puzzling.
barakn
3 / 5 (2) Feb 13, 2013
But wait, there's another one. Mars's South Polar cap is so asymmetrical that during the summer the pole is ice free - http://www.lpi.us...30-c.jpg . So there you have it - your disbelief is a product of your own failed logic, not because of reality.
R_R
1 / 5 (6) Feb 14, 2013
Barakn, dont go counting your chickens before they hatch.

1 - Greenland - is left over Hudson bay Ice cap from before pole shift. It acts as its own freezer preserving ice cover, if this area had been ice free 10,000 years ago as was the cities you mentioned it too would have similiar characteristics.

The arctic circle shifted but Greenland managed to stay within it.

2 - Mars - From Wiki "The residual southern ice cap is misplaced. That is it is not centered on the south pole. However, *** the south seasonal cap is centered near the geographic pole ***"

You are talking about an area just 300 miles wide well within the polar circle, doesnt compare to 3500 miles of ice leaving the polar circle way behind reaching for the equater.

Your disbelief is a product of your brainwashing
barakn
3 / 5 (2) Feb 14, 2013
1 - Greenland ... acts as its own freezer preserving ice cover,
And that's different from the ice-age glaciers how? Let me paraphrase your argument for you: "Asymmetric polar caps can NOT exist. Asymmetric polar caps that do exist support my theory."
2 - Mars - From Wiki "The residual southern ice cap is misplaced. That is it is not centered on the south pole. However, *** the south seasonal cap is centered near the geographic pole ***"
The south seasonal cap is the Martian equivalent to winter snow here on Earth. Unless you're going to try to claim that snow never falls in winter in Siberia, the south seasonal cap is completely irrelevant.
R_R
1 / 5 (6) Feb 14, 2013
Barakn, Both of your examples are areas within planets polar circle regions, lots of variables in play. The north american ice fields of your ice age extented 2000 miles south of the arctic circle. At the same time in Siberia and Alaska, almost right beside todays pole, there was no ice, but millions of Elephants Rhinos etc. Show an example of "that" on any planet in any solar system and then you have a point.

There is no mystery here, just a lie too big too fathom yet.
Maggnus
3 / 5 (4) Feb 14, 2013
At the same time in Siberia and Alaska, almost right beside todays pole, there was no ice, but millions of Elephants Rhinos etc. Show an example of "that" on any planet in any solar system and then you have a point.


Are you are trying to suggest that the ice sheets that advanced in North America during the last ice age did not extend into Siberia and Alaska? Can you point to any data that supports that rather unconventional view?
R_R
1 / 5 (4) Feb 14, 2013
New Scientist-Siberia a wildlife refuge in last Ice Age - 10 Jan 2012

"SIBERIA, a name that conjures up images of snow and ice, may have been an unlikely refuge from the bitter cold of the last ice age. Ancient DNA from the region paints a picture of remarkably stable animal and plant life in the teeth of plunging temperatures"

"The samples were extracted from 15,000 to 25,000-year-old frozen sediment in southern Chukotka in north-eastern Siberia. Their age is significant: around 20,000 years ago temperatures plummeted and ice sheets blanketed much of the northern hemisphere - but parts of Siberia, Canada and Alaska apparently stayed ice-free "