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Re: dinosaur upland faunas?
Pieter.Depuydt (5/29/97; 5:29pm) cited evidence (from Fastovsky et al.
JVP article) that the La Boca Formation is upland due to evidence of a
debris flow moving across a surface of considerable relief. Debris flows
are common around coastal cliffs, so the cited evidence is not adequate
to establish that the deposit formed in an upland setting.
When I think of uplands, my fevered brain conjurs up scenes from the
Colorado Plateau, the Rockies, and Blue Ridge. Rough, "truly" upland
terrain may have been relatively more widespread in the Mesozoic than
now, because higher sea level covered more of the low-lying craton than
now, including inland regions as well as coastal regions. I think it is
correct that no dinosaur remains can be documented as having been derived
from such truly upland settings, which means we are missing much (most?)
of the picture.
Likewise, I don't think (OK, I'm bluffing here) the remains of any
mountain goats that died in Colorado have been found in Missouri. If the
skeletal remains are significantly larger than the particles making up
the siliciclastic sediment fraction, then they haven't come from very far
away. They would be highly abraded--rounded, even, within a few miles
of their source, as happens to much more resistant non-biogenic sediment
particles. Moreover, studies following floods show that bodies tend to
wash toward the slackwaters marginal to the main current in a very short
distance, so not even bloated carcasses can be carried very far down
Norman R. King tel: (812) 464-1794
Department of Geosciences fax: (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712 e-mail: email@example.com