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Re: Burnt fossil bones
Tyler,
Very interesting abstract! Thanks. Marilyn's paper also serves a dual
use as a reference on the subject of impact-caused wildfires, so I will
also include it in my Extinction_References bibliography
In the interest of citation completeness, where was this meeting held?
And is there a page number?
<pb>
--
On Mon, 03 Jul 2006 17:28:09 -0600 tjshaw@ualberta.ca writes:
> This is an abstract from a poster presented at the Dinosaur Park
> Symposium (September 2005). Hope it helps.
> -Tyler
>
> Paleowildfire characteristics and behavior: diagenetic changes
> occurring in vascular bone during cremation by wildfire reveal
> ancient
> fire behavior.
> Marilyn D. Wegweiser
> Paleowildfire behavior can be ascertained by examining
> changes that
> occur in vascular bone during cremation. Vascular bone of ancient
> animals that were alive or recently dead during cremation exhibits
> color and mineralogical changes consistent with those changes that
> occur in modern vascular bone. Burned bone becomes inert, remaining
> unchanged during fossilization processes, and thus provides a record
> of
> ancient wildfire behavior. Morphological changes in bone indicate
> the
> potential range of fire behavior, from a ground or brush fire to a
> crowning fire. In some instances, extreme fire behavior can be
> implied
> from the morphopmetric changes induced in bone. Because the
> paleolatitude of Wyoming¡¯s Big Horn Basin in the Late Cretaceous
> (70-66.5 Ma) was close to present day latitude , it is reasonable to
>
> suspect this region was equally vulnerable to ancient Pacific Ocean
> and
> Interior Seaway currents influencing the climate resulting in
> seasonal
> wildfires. Fossil evidence of paleowildfires from northwestern
> Wyoming
> led me to compare modern cremated vascular bone with dinosaur bone
> found associated with fossilized charcoal and bu8rned wood bearing
> fire scars. Late Cretaceous dinosaur bone from the Meeteetse
> Formation
> of Wyoming exhibits morphological changes that are similar to those
> found in modern vascular bone that had undergone changes during
> cremation. The nature of the changes, including crescentic
> fractures,
> reorganization of osteocytes, and glassification of CaPO4, suggests
> a
> ground fire of long duration with sustained temperatures in the
> range
> of 650¢ªC to 800¢ªC, or a crowning fire with temperatures in excess
> of
> 1200¢ªC. Identification of sedimentary layers containing
> paleowildfires
> provides a powerful tool for better understanding cyclicity of
> wildfire
> in association with other regional climatic signals or patterns,
> provides clues to the ecology of ancient trophic environments, and
> provides a possible chronostratigraphic tool for regional
> correlation.
>
> Quoting Phillip Bigelow <bigelowp@juno.com>:
>
> >
> > Or maybe: "Bones that appear to have been burnt before
> fossilization".
> >
> > Does anyone have any refs. on this? Especially any refs on the
> > petrography of the fossil bone.
> >
> > During this afternoon's chicken BBQ, I got into a discussion
> (actually a
> > polite argument) with a professional forester on the subject of
> how one
> > would determine if fossilized dinosaur bones show a "fingerprint"
> of
> > having been burned by fire prior to burial.
> >
> > I figured that taphonomy gurus Behrensmeyer or Shipman would have
> had
> > something to say on this subject, but so far, I'm pullin' up
> nuthin'.
> >
> > And has anyone made a chicken marinade of vodka, black peppercorns
> > garlic, and maraschino cherry juice? If not, then I hereby dub
> the
> > marinade "Phil's Chicken Soused".
> >
> > <pb>
> > --
> >
> >
> >
> >
> >
> >
> >
>
>
>
>
--
Personal science advisor on enviromental issues to Sen. James Inhofe
(R-OK)
http://inhofe.senate.gov/