[meteorite-list] Evidence of Late Quaternary Fires from Charcoal and Siliceous Aggregates, Eastern US
From: Paul <etchplain_at_meteoritecentral.com>
Date: Tue, 25 Feb 2020 15:26:54 -0600
It was pointed out to me that Ballard has a 2015 PhD Dissertation
Ballard, J.P., 2015. Evidence of Late Quaternary Fires from Charcoal
and Siliceous Aggregates in Lake Sediments in the Eastern USA.
PhD Dissertation, University of Tenneessee, Knoxville
The abstract in part states:
"A new microscopic charcoal record from Anderson Pond, Tennessee
revealed high fire activity from 23,000?15,000 cal yr BP when
conifers dominated, and during the Mid-Holocene Warm Period
(8000?5200 cal yr BP), when hardwoods dominated. Macroscopic
charcoal analysis of sediments from Pigeon Marsh, Georgia
showed high fire activity from 16,500?14,500 cal yr BP, below
a major hiatus. Jackson Pond, Kentucky and Cahaba Pond, Alabama
had low macroscopic charcoal concentrations during the late
glacial; largest charcoal peaks occurred around 5000 cal yr BP
?at Jackson Pond, and from 1370?640 cal yr BP at Cahaba Pond."
A related paper is:
Marlon, J.R., Bartlein, P.J., Walsh, M.K., Harrison, S.P., Brown, K.J.,
Edwards, M.E., Higuera, P.E., Power, M.J., Anderson, R.S., Briles,
C. and Brunelle, A., 2009. Wildfire responses to abrupt climate
change in North America. Proceedings of the National Academy
of Sciences, 106(8), pp.2519-2524.
The abstract reads in part.
"We also test the hypothesis that a comet impact initiated continental
-scale wildfires at 12.9 ka; the data do not support this idea, nor are
continent-wide fires indicated at any time during deglaciation. There
are, however, clear links between large climate changes and fire
activity. Biomass burning gradually increased from the glacial period
to the beginning of the Younger Dryas. Although there are changes
in biomass burning during the Younger Dryas, there is no systematic
trend. There is a further increase in biomass burning after the
Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and
11.7 ka are marked by large increases in fire activity. The timing of
changes in fire is not coincident with changes in human population
density or the timing of the extinction of the megafauna."
Received on Tue 25 Feb 2020 04:26:54 PM PST