[meteorite-list] Younger Dryas Impact Hypothesis and Missoula (Spokane) Megafloods

From: Paul <etchplain_at_meteoritecentral.com>
Date: Sat, 14 Oct 2017 10:30:54 -0500
Message-ID: <39a27101-abef-6f0b-fcc1-8db2a6cf1e65_at_att.net>

There is a new paper containing research about the
Missoula (Spokane) megafloods that contain bad news
for those few proponents of the Younger Dryas impact
hypothesis, who argue that these megafloods were
a single megaflood and caused by a hypothetical Younger
Dryas Impact.

It is:

Balbas, A.M., Barth, A.M., Clark, P.U., Clark, J., Caffee,
M., O?Connor, J., Baker, V.R., Konrad, K. and Bjornstad,
B., 2017. 10Be dating of late Pleistocene megafloods
and Cordilleran Ice Sheet retreat in the northwestern
United States. Geology, 45(7), pp.583-586
http://iafi.org/wp-content/uploads/Balbas2017-Missoula-Flood-Chronology.pdf
http://iafi.org/iafi/resources/
http://iafi.org/iafi/beryllium-10-dating-of-late-pleistocene-megafloods-and-cordilleran-ice-sheet-retreat/

This paper contains cosmogenic 10Be ages that directly
date flood and glacial features important to understanding
the flood history, the evolution of the Channeled Scabland,
and relationships to the Cordilleran Ice Sheet. Popular
authors of lay books for the general public, lecturers, and
podcasters, e.g. Graham Hancock and Randall Carlson cannot
dismiss these dates as they did any radiocarbon dates that
contradicted their beliefs as being older wood / bone
reworked from older sediments.

The last of the larger megafloods occurred at 18.2 ? 1.5 ka. It
flowed down the northwestern Columbia River valley prior to
blockage of this route by advance of the Okanogan ice lobe
of the Cordilleran Ice Sheet. The largest of multiple megafloods
predates the alleged Younger Dryas impact event by thousands
of years.

These dates show that the last of the megafloods from
glacial Lake Missoula occurred at about 14.7 ? 1.2 ka. The
youngest of the dated megaflood(s) (14.0 ? 1.4 ka to
14.4 ? 1.3 ka) likely came from glacial Lake Columbia,
indicating that the lake persisted for a few centuries after
the last Missoula megaflood. The last of the megafloods
predate the alleged Younger Dryas impact event by
thousands of years and came from two different sources.
The multiple megafloods that all are older than the
start of the Younger Dryas and, as a result, cannot be
associated with a hypothetical Younger Dryas event
as a few self-taught avocational investigators argue.

That there were multiple the Missoula (Spokane) megafloods
that predated a hypothetical Younger Dryas Impact is a
long standing idea based on solid evidence is shown by an
older and related Friends of the Pleistocene field trip
guidebook. It is:

Waitt, R.B., 1983. Tens of successive, colossal Missoula
floods at north and east margins of channeled scablands.
Friends of the Pleistocene, Rocky Mountain Cell, Guidebook
for 1983 Field Conference Day 2: 27 August 1983
U.S. Geological Survey Open-File Report 83-671
https://pubs.usgs.gov/of/1983/0671/report.pdf

More recent research will be presented at the October
22nd Geological Society of America (GSA) Annual Meeting
in Seattle. Go see:

Session No. 22. T174. Cordilleran Ice Sheet Outburst
Floods: From Glacial Lake Missoula to the Hubbard Glacier.
Sunday, 22 October 2017: 8:00 AM-12:00 PM.
GSA Annual Meeting in Seattle, Washington, USA - 2017
https://gsa.confex.com/gsa/2017AM/webprogram/Session43011.html

Yours,

Paul H.
Received on Sat 14 Oct 2017 11:30:54 AM PDT