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

From: Paul <bristolia_at_meteoritecentral.com>
Date: Tue, 13 Oct 2009 05:35:18 -0700 (PDT)
Message-ID: <841852.26181.qm_at_web36201.mail.mud.yahoo.com>

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


      
Received on Tue 13 Oct 2009 08:35:18 AM PDT