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Evidence for an extraterrestrial impact 12,900 years ago
Proceedings of the National Academy of Sciences, October 9, 2007, Vol. 104 ^ | Setember 27, 2007 | R. B. Firestone, et. al.

Posted on 09/30/2007 10:14:28 AM PDT by baynut

A carbon-rich black layer, dating to 12.9 ka, has been previously identified at 50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur below this black layer but not within or above it. Causes for the extinctions, YD cooling, and termination of Clovis culture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at 12.9 ka, which we hypothesize caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. Clovis-age sites in North American are overlain by a thin, discrete layer with varying peak abundances of (i)magnetic grains with iridium, (ii) magnetic microspherules, (iii) charcoal, (iv) soot, (v) carbon spherules, (vi) glass-like carbon containing nanodiamonds, and (vii) fullerenes with ET helium, all of which are evidence for an ET impact and associated biomass burning at 12.9 ka. This layer also extends throughout at least 15 Carolina Bays, which are unique, elliptical depressions, oriented to the northwest across the Atlantic Coastal Plain. We propose that one or more large, low-density ET objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering YD cooling. The shock wave, thermal pulse, and event-related environmental effects (e.g., extensive biomass burning and food limitations) contributed to end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America.


TOPICS: Science
KEYWORDS: catastrophe; catastrophism; climate; clovis; clovisimpact; comet; extinction; godsgravesglyphs; impact; meadowcroft
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To: Coyoteman
I was never very comfortable with that idea.

No doubt; I honestly don't know enough about the "mechanics" of the theory to form an opinion on way or the other. That's why I pinged you to the article. From the looks of things, this may be the reason Firestone and Topping split the sheets -- at least for a while.

Did you happen to read Topping's COUNTER-REBUTTAL to see how well he defended their or HIS conclusions re the carbon dating "anamolies"?

41 posted on 10/02/2007 9:56:39 AM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake

There was a split; Bill Topping (I think that’s his name) first turned in the direction of an ET cause, but at some point (perhaps as the “new guy” added members to the team) parted company. :’) Not sure what you mean about 40K-50K too young for RC dates — the RC limit is around 50K, beyond which the level of 14C is too low. However, there were some 14C “spikes” which caused older stuff to appear younger, as the ratio was thrown off. That is discussed in the book. Other radiometric stuff is discussed as well. The earlier waves of bombardments are discussed quickly, but I suspect those will someday be fleshed out.


42 posted on 10/02/2007 10:11:20 AM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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To: ForGod'sSake

Thanks again:

http://abob.libs.uga.edu/bobk/nucbtrev.html

[snip] As a factual matter there “is” a pattern to abnormally young dates in the Great Lakes region of North America. The sources for these dates were documented thoroughly, and clearly presented in the article. Among Paleo-Indian specialists (relatively few), this pattern is well-known. In addition, we discussed extinctions and mutations that are chronologically related, and based on evidence for prehistoric neutron flux most likely a direct result. “Depleted” Uranium 235 is caused by neutrons, and the excessive Plutonium 239 found in various Paleo-Indian artifacts also is attributable to “neutrons in prehistory” considering all available evidence. The genesis of 14C is neutrons (14N + n = 14C), and the fact that we have hard evidence for prehistoric neutrons necessarily means 14C had to have been produced both in situ, and in the atmosphere. [unsnip]


43 posted on 10/02/2007 11:02:07 AM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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To: SunkenCiv
From the ORIGINAL ARTICLE:

Redating North American sites

The 39,000 yr B.P. date proposed for the Gainey site is consistent with the prevailing opinion among many archaeologists about when the Americas were populated. It is also commensurate with dates for South American sites and with a Mousterian toolkit tradition that many see as the Paleoindian precursor. The proposed date for the Gainey site also falls closer in line with the radiocarbon date for a Lewisville, Texas, Paleoindian site of 26,610 ± 300 yr B.P.22,23 and radiocarbon dates as early as c. 20,000 yr B.P. for Meadowcroft Rockshelter.24 Since the Lewisville and Meadowcroft sites were likely exposed at the same time to thermal neutrons, we estimate that their dates should be reset to c. 55,000 yr B.P. and c. 45,000 yr B.P., respectively.

It is likely that Paleoindians occupied low latitudes during the full glacial and migrated to more northerly areas as the ice front retreated. Therefore the pattern of dates makes sense from the archaeologist's point of view. Dates for North American sites should generally be reset by up to 40,000 years, depending on latitude and overburden.

Geologists believe that before c. 15,000 yr B.P. the Wisconsinan glaciation covered the more northerly locations where Paleoindian sites have been found.25 The ice sheet would have shielded the landscape and any artifacts from an irradiation. (The Gainey thermoluminescence date of 12,400 yr B.P. is probably a result of the heat generated by the nuclear bombardment at that time, which would have reset the TL index to zero.) The modified dates for Paleoindian settlements suggest that the timetable for glacial advance sequences, strongly driven by conventional radiocarbon dates, should be revisited in light of the evidence presented here of much older occupations than previously thought."

THAT of course from 2001. I don't know if Topping and/or Firestone are still willing to defend his/their theory re the anomalous carbon dates, but some of that information has been included in the article at the head of this thread -- FWIW.

44 posted on 10/02/2007 11:04:22 AM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake

Ah, I see what you mean. Perhaps it was that issue that led to the split.


45 posted on 10/02/2007 11:13:08 AM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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To: SunkenCiv; Coyoteman
Perhaps it was that issue that led to the split.

Impossible to say at this point.

Maybe Coyoteman will be able to get a look at the papers and share some insights.

46 posted on 10/02/2007 4:34:46 PM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake
Maybe Coyoteman will be able to get a look at the papers and share some insights.

I was never convinced by the explanation for radiocarbon dating problems in Great Lakes region posited by that early paper.

A subsequent article in the Mammoth Trumpet seems to be pretty convincing. This is: Update: Article Questioning Radiocarbon-dating Accuracy Draws Fire from Scientists.

The real meat of the article is Brief Comments on "Terrestrial Evidence of a Nuclear Catastrophe in Paleoindian Times," by Richard B. Firestone and William Topping, written by John R. Southon and R. E. Taylor. Firestone has a response following, but I think I would follow Southon and Taylor in this one. I don't know Southon, but Taylor has been at this for many years and is not known for going off on wild goose chases.

All of this is reinforced by the most recent article (Goodyear et al. 2007).

There still may be some problem with some radiocarbon dating in the Great Lakes region, but this article may hold the key to understanding just what that problem is.

The meteor or some other ET strike at about 12,900 years ago seems to be a good explanation for a lot of things.

I think these folks may be on the right track--they have a lot of data, and that's always a good start!

47 posted on 10/02/2007 6:54:42 PM PDT by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Coyoteman
The meteor or some other ET strike at about 12,900 years ago seems to be a good explanation for a lot of things.

Yes indeed. So, from this I gather you would accept the notion that an impact/air burst from an errant space traveler could affect carbon dating? What little of the evidence I was able to understand seems to support that.

Another item; while doing some scouting around the web to see if there were other areas in the world affected by this event -- holy cow! Mega die-offs in much of the world of large critters INCLUDING the southern hemisphere, all at roughly the same time -- in all probability, a single event. This one was a biggie that seems to have been all but ignored until Firestone et al started making waves. Even at that it's been nearly 20 years since they began work on it, and about 6 years since their first publication.

Which all seems pretty odd when you consider this event occurred almost under our noses during what is generally considered historcal times. Some of our early ancestors actually lived through it! Must have been quite a show.

48 posted on 10/02/2007 8:56:07 PM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake
>The meteor or some other ET strike at about 12,900 years ago seems to be a good explanation for a lot of things.

Yes indeed. So, from this I gather you would accept the notion that an impact/air burst from an errant space traveler could affect carbon dating? What little of the evidence I was able to understand seems to support that.

It just might affect some dates. There was an article some years back pointing out problems in just that area:

Lee, Robert E., 1981. Radiocarbon: Ages in error. Anthropological Journal of Canada 19(3): 9-29. Reprinted in Creation Research Society Quarterly 19(2): 117-127 (1982).

Creationists have made a lot of hay by combining a couple of quotes (some 20+ pages apart) from this article into one quote, but it is possible the author was describing a real problem related to the ET event in that particular area. Creationists, of course, use this potential local anomaly to deny the efficacy of the radiocarbon method in general--but what do they really know about science, eh? (A little Canadian lingo there.)

Another item; while doing some scouting around the web to see if there were other areas in the world affected by this event -- holy cow! Mega die-offs in much of the world of large critters INCLUDING the southern hemisphere, all at roughly the same time -- in all probability, a single event. This one was a biggie that seems to have been all but ignored until Firestone et al started making waves. Even at that it's been nearly 20 years since they began work on it, and about 6 years since their first publication.

From the recent article (Goodyear et al. 2007), it sounds like they may really be onto something. The Younger Dryas could easily have been a large-scale event. I don't know that the original article's explanation is holding up as well.

Which all seems pretty odd when you consider this event occurred almost under our noses during what is generally considered historcal times. Some of our early ancestors actually lived through it! Must have been quite a show.

All of our ancestors lived through it! Otherwise, they wouldn't be our ancestors. :-)

The (Goodyear et al. 2007) article has a lot of quantitative data, and I think that theory is going to be hard to beat.

I know one of the co-authors and I'll see what I can pick up from him.

49 posted on 10/02/2007 9:16:54 PM PDT by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Coyoteman
From the recent article (Goodyear et al. 2007), it sounds like they may really be onto something.

I did a quick search for recent articles with Al Goodyear and didn't find anything. Are you referring to the article from this thread, in which he played a part??? If not, a little help; I'd really like to see that.

All of our ancestors lived through it! Otherwise, they wouldn't be our ancestors. :-)

Ouch -- and we wouldn't be here!

I know one of the co-authors and I'll see what I can pick up from him.

Cool. Now I GOTTA hit the sack.

50 posted on 10/02/2007 10:11:39 PM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake; Coyoteman

I believe there’s some old topics about RC data from coral, somewhere around here; some study (or perhaps it was more than one, I’m too lazy to check right now, long hard night at the office) regarding the RC spikes recorded in coral are cited in the book (I think, again, lazy, tired). I’ll look for FR links and post them in the next reply (so it doesn’t frog up the “my comments” screen for you.


51 posted on 10/02/2007 10:12:07 PM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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Neanderthal Man ‘Never Walked In Northern Europe’
The Telegraph (UK) | 8-22-2004 | Tony Paterson
Posted on 08/21/2004 10:25:32 PM EDT by blam
http://www.freerepublic.com/focus/news/1196571/posts

in particular:
http://www.freerepublic.com/focus/news/1196571/posts?page=135#135

also...

Humans vs. Neanderthals: Game Over Earlier
LiveScience | 22 February 2006 | Associated Press
Posted on 02/23/2006 1:25:12 AM EST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1583943/posts

...Two new studies of stratified radiocarbon in the Cariaco Basin, near Venezuela, and of radiocarbon on fossilized coral formations in the tropical Atlantic and Pacific have given scientists a better idea of the amount of carbon in the atmosphere over the last 50,000 years.


52 posted on 10/02/2007 10:37:20 PM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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To: ForGod'sSake
I did a quick search for recent articles with Al Goodyear and didn't find anything. Are you referring to the article from this thread, in which he played a part???

Yup, I mislabeled the pdf file with the wrong tire maker; it should be Firestone et al. (2007), not Goodyear. That is the article which is the subject of this thread.

53 posted on 10/03/2007 7:42:22 AM PDT by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: SunkenCiv

I suppose the upshot of all this is carbon dating is absolutely correct......to a point. Any readings should somehow be reconciled against background levels, which is easier said than done — apparently.


54 posted on 10/03/2007 7:42:51 AM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: Coyoteman
Yup, I mislabeled the pdf file with the wrong tire maker; it should be Firestone et al. (2007), not Goodyear.

Good; I thought I had missed something.......again.

55 posted on 10/03/2007 7:46:31 AM PDT by ForGod'sSake (ABCNNBCBS: An enemy at the gates is less formidable, for he is known and carries his banner openly.)
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To: ForGod'sSake

It means the RC dates loop back on themselves, making older stuff appear newer as a result of events of this kind; there was already variability from year to year, region to region.


56 posted on 10/03/2007 8:01:42 AM PDT by SunkenCiv (Profile updated Wednesday, September 27, 2007. https://secure.freerepublic.com/donate/)
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