Description for file +quot;footprints.gif+quot; 769 X 1308 pixels, 1 bitplane. Part of fig
From: email@example.com (R. Andrew MacRae)
Description for file "footprints.gif" 769 X 1308 pixels, 1 bitplane.
Part of figure 88 of Balsley, 1980.
Balsley, John K., 1980. Cretaceous wave-dominated delta systems:
Book Cliffs, east central Utah: a field guide. Unpublished. Amoco
Production Company, Denver Coldorado, p.1-163. [Although
unpublished, this book is a classic available in most univerisity
This is a map of the roof (top surface) of a coal seam in an
abandoned mine located in late Cretaceous rocks of the Blackhawk
Formation, near Price, southeastern Utah. This is but one of many
similar occurrences in the area. Many local miners have footprints
as doorstops :-), or you can view specimens in the Price museum
The scale (15 feet) is located at the bottom of the image.
The large, black rectangular areas are "pillars" of coal left to
support the roof (I filled them with black so the image would
The seam has the coalified stumps of trees (the black, radiating
symbols) growing on the coal surface (then peat), fallen logs and
branches (the elongate rectangular, outlined symbols ), and numerous
dinosaur tracks of several species (the 3-lobed, black symbols). The
shape and size of the three symbols approximates their real
appearance (photos also in Balsley).
Balsley provides the following description of these and other
features of the sediments within and on top of the coal seam (p.
"Stands of large trees and palm thickets have been preserved in
growth position. Root systems of the larger trees extend
horizontally across the peat surface and show development of the
northwest-southwest orientation discussed earlier [this is
perpendicular the regional paleoshoreline]. Where roof falls have
occurred, the vitrianized [coalified] tree trunks are commonly
exposed in cross section. .... The spacings of the trees are similar
to the spacings of Cypress trees in Okefenokee Swamp. Here, tree
spacings are determined by crown widths. Occasionally, leaf floras
are preserved on the basal surfaces of the flood deposits [on top of
the coal seam - he is talking about _river_ floods :-)]. The leaf
assemblages are commonly dominated by broad-leaf angiosperm genera
with a scattering of palms, conifers, and ferns... Charcoal in the
coals suggests that during the dry seasons, fires swept through the
swamps as they do in modern Okefenokee.....
In the swamp forests, the peat surfaces have been deformed by
vast numbers of dinosaur footprints [some of which he illustrates as
photographs]. The footprints are depressions in the swamp peats that
have been filled with flood-deposited sediment..... Peat is a
water-saturated material that after compression tends to rebound to
its undisturbed state. The abundance of well-defined tracks suggests
that they were made just prior to the deposition of the sediment and
that dinosaurs were very abundant in the swamp forests...
Occasionally, tracks of three-toed dinosaurs [probably hadrosaurs],
occur around the bases of the trees, and are pointed inward as though
the animals were browsing on the standing vegetation. The large
numbers of well-defined, three-toed tracks and their association with
trees suggest that the parent dinosaurs were gregarious herbivores.
Occasionally, single trackways can be followed for considerable
distances in mine entries driven parallel to the paths of the
Once creation "scientists" finish explaining this section,
they can start on the rest of the book :-)
E-Mail Fredric L. Rice / The Skeptic Tank