[meteorite-list] North America comet theory questioned was “Dryas all wet”

[Paul]

In http://six.pairlist.net/pipermail/meteorite-list/2009-October/057294.html ,
Darren Garrison wrote:

“ http://www.nature.com/news/2009/091012/full/news.2009.997.html 

North America comet theory questioned”

Rest of text deleted.

The full reference to the article at the above URL is:

North America comet theory questioned. No evidence of an extraterrestrial 
impact 13,000 years ago, studies say by Rex Dalton, Nature News, Published 
online October 12, 2009, doi:10.1038/news.2009.997 

The paper is:

Surovell, T. A., V. T. Holliday, J. A. M. Gingerich, C. Ketron, C. Vance 
Haynes, Jr., I. Hilman, D. P. Wagner, E. Johnson, and P. Claeyse. 2009, 
An independent evaluation of the Younger Dryas extraterrestrial impact 
hypothesis. Published online before print October 12, 2009, 
doi: 10.1073/pnas.0907857106, 

http://www.pnas.org/content/early/2009/10/09/0907857106

This reminds me of the claims made by a group of researchers, which 
included Luann Becker, for indicators of an extraterrestrial impact
at the Permian - Triassic and the Bedout High structure being the 
impact crater. Papers were published arguing that evidence of 
extraterrestrial impact, including fullerenes containing extraterrestrial 
3He, are found at the Permian - Triassic boundary. Later researchers, 
who restudied various Permian - Triassic boundary outcrops, including 
the ones studied by Becker, and were unable to replicate their findings. 
The evidence used to argue for Bedout High being an impact structure 
either could not be replicate or turned out to be open to alternative 
interpretations. Finally, there is a considerable amount of controversy 
whether many of the fullerenes found in sediments are even of 
extraterrestrial origin.

Best Regards,

Paul