Study Disputes Younger Dryas Event Comet

Study Disputes Younger Dryas Event Comet

Study Questions Younger Dryas Event Comet
Theories, Red Orbit, May 14, 2014
http://www.redorbit.com/news/science/1113145713/younger-dryas-event-comet-impact-theory-051414/

Research team claims no evidence of
extraterrestrial impact causing Younger
Dryas deep freeze, PhysOrg, May 13, 2104
http://phys.org/news/2014-05-team-evidence-extraterrestrial-impact-younger.html
http://phys.org/wire-news/161418589/comet-theory-doesnt-explain-cold-snap-at-the-end-of-the-ice-age.html

Meltzer, D. J., V. T. Holliday, M. D. Cannon, and
D. S. Miller, 2014, Chronological evidence fails to
support claim of an isochronous widespread layer of
cosmic impact indicators dated to 12,800 years ago.
Proceedings of the National Academy of Science
of the United Staea of America. Early Edition.
http://www.pnas.org/content/early/2014/05/08/1401150111.abstract

Yours,

Paul H.

Abstract About Younger Dryas Event Record In Midwest Lake Deposits

Paul Heinrich oxytropidoceras at cox.net
Sun Feb 21 23:57:21 EST 2010

Dear Friends,

I came across the following abstract about ongoing research
concerning trhe Younger Dryas impact hypothesis. It is:

Gill, J. L., J. P. Marsicek, J. P. Donnelly, B. Simonson, and
J. W. Williams, 2009, Do lake sediment records show evidence
of a Younger Dryas impact event or its potential ecological effects?
Abstract COS 13-5, The 94th ESA Annual Meeting (August 2 --
7, 2009) Albuquerque, New Mexico.

http://eco.confex.com/eco/2009/techprogram/P20277.HTM

In part, the abstract states:

"We collected sediment cores from Appleman and Spicer
Lakes, IN, Silver Lake, OH, and Kirchner Marsh, MN, with
radiocarbon-dated records spanning the YD. Our sites are
ideally situated to record regional environmental responses
to a nearby impact."

It concludes:

"Results from LOI, magnetics, microspherules, charcoal and
XRF do not show the signatures predicted for a YD event.
Vegetation reconstructions are still in progress as of the time
of this abstract, but at Appleman, the Sporormiella decline
precedes the YD. We are continuing analyses to determine
whether this apparent discrepancy between the predictions of
the YD impact hypothesis and the lack of evidence in lake
sediments persist across sites."

It is part of the "COS 13 - Paleoecology" session at:

http://eco.confex.com/eco/2009/techprogram/S4761.HTM

Yours,

Paul H.

North America comet theory questioned was “Dryas all wet”

Paul bristolia at yahoo.com
Tue Oct 13 08:35:18 EDT 2009

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