|One rendition of the putative [and now forever debunked] Younger Dryas Impact theory.|
Kathleen Nicoll (U. Utah) alerted me to this yesterday when she sent a reprint. Tip o’ the hat, Kathleen. She’s second author on this paper. The news is all over the science pages on the web, too. So, I’m certain that you all prolly know evrything ’bout it. Still, there may be one or two. Well, this one’s for you!
M. Boslough, K. Nicoll, V. Holliday, T.L. Daulton, D. Meltzer, N. Pinter, A.C. Scott, T. Surovell, P. Claeys, J. Gill, F. Paquay, J. Marlon, P. Bartlein, C. Whitlock, D. Grayson, and A.J.T. Jull (2012), Arguments and evidence against a Younger Dryas impact event, in Climates, Landscapes, and Civilizations, Geophys. Monogr. Ser., vol. 198, edited by L. Giosan et al. 13–26, AGU, Washington, D. C., doi:10.1029/2012GM001209.
|A Clovis ‘point’
[or double-edged sword, if you prefer]
This paper exposes the fanciful nature of claims made for an extraterrestrial body that was supposed to have created an environmental cataclysm at the beginning of the latest of the Pleistocene glaciations—the Younger Dryas. Alongside these claims was the argument that this would have spelled doom for the so-called Clovis people who inhabited North America between about 14 and about 12 kyr ago.
Boslough et al. first give lie to the various scenarios that the Younger Dryas impact proponents have erected to explain a) an impact with no impact crater, and b) the impossibility of an ‘airburst’ of sufficient magnitude to have spread its destructive energy across North America south of the ice margin. Put simply, even if a sufficiently large object had made contact on the waning Laurentide Ice Sheet there would have been impact evidence on the ground in the present. No such exist. As for the ‘airburst’ idea, physical principles tell us that to have been large enough to create a continent-wide cataclysm it needed to have broken up well above Earth’s atmosphere [i.e. in space, fer gawd’s sake!] and unless there had been a gigantic explosion inside the offending celestial body, and that even if had broken up through some mysterious, previously unheralded physical laws, such a missile would simply have continued on its course, with the various bits in close formation, and have had the same ‘footprint’ as if it had been all one piece.
Planet Jupiter. The four brown patches are, give or take, the impact points
of four fragments of the Comet Shoemaker–Levy 9, in 1994. This was the
first time a human being had witnessed the collision of two celestial bodies.
If that weren’t enough to put the YD impact idea in the circular file, the authors go on to point out the shortcomings of the sedimentary and chronological record that YD enthusiasts claim amounts to de facto evidence of an extraterrestrial impact: specifically, the so called Black Mats that in places occur around the time of the Younger Dryas. They occur at other times, and far enough away from the lower half of North America that they can’t be used as a time marker, much less as evidence—in and of themselves—for such impacts. The authors also find erroneously identified materials used as evidence, contaminated samples, poorly dated sediments, and on and on. Read it. This paper eviscerates the YD impact theory. And, although we’re not treated to the actual physics computations I think we can be fairly certain that the counter-claims made in this article will stand up in the court of archaeological opinion. That’s because Boslough is the guy who accurately predicted the effects of the break up and impact on Jupiter of the comet Shoemaker-Levy 9 in mid 1994, and whose model won out against the prognostications of the rest of the scientists in the field.
(CREDIT: Photograph courtesy of Claudio Latorre.)
The team that put this paper together comprise the glitteratti of a half-dozen scientific disciplines, including our own. Not that I’m appealing to authority here [everyone knows THAT’s fallacious]. I’m merely pointing out that this is no *cough*cflash-in-the-pan, slash and *cough, cough* burn, criticism. They dismantle the YD impact theory. Full stop.
This is the kind of scrutiny that needs to be applied to every [and I mean every] one of the claims of the kind the Subversive Archaeologist is determined to overturn. I’ve been going to say this for a few weeks now, but couldn’t find the right platform. Now I can. With independent and non-partisan examination, could we not—for example—once and for all, address the possibly erroneous early dates for modern human behaviour from the caves of southern Africa? I focus on this one simply because I’m not a physicist. Neither were the YD impacts proponents. And, although the OSL daters of those south African caves are physicists, too, I think their technique [or more correctly, their method] is due for a thorough going over.
As for the other kind of issue—e.g.purposeful burial in the Middle Palaeolithic. I think these can be dealt with just fine, thank you, by unblinkered archaeologists [with a little informed help from geologists]. Early claims for fire use, however, can’t be dealt with by us archaeologists alone. Even the much touted record of presumed ‘hearths’ at Kebara Cave could do with a re-visit [I believe]. Patrick Randolph-Quinney, one of the SA‘s staunchest supporters, is ready, willing and quite able, I think, to apply forensic science approaches to the early fire question. [Hope ya don’t mind me singling you out, Patrick!]
The point is: the work is there to be done. And although several people have asked me to work with them on some of the issues, I truly believe my mind is best applied to my activities at the Subversive Archaeologist. I’m happy pointing you in the right direction.
With that in mind. Get busy! Great things are afoot!
Oh. And. I still have work to do on the “Out of Africa, Out of Africa Again, and Yet Again Out of Africa” business recently posited by Boivin et al.
Thanks for making my day!