"Let me pin you down on this. I've never done any formal research
in the Grand Canyon area (I wish I could!) although I have taught
the "standard" geologic model regarding the rock units present there.
Can you steer me toward a couple of what you consider to be the best
pieces of published research (I'm not even going to ask that they be
in a mainstream journal) regarding strong evidence for a few thousand
year old flood resulting in strata present within the Canyon? I'd be
more than happy to read those papers."
Art replied (complete reply archived at http://www.calvin.edu/archive/
asa/199802/0235.html) with some references to his work on the Toroweap
Formation in the Grand Canyon, which I haven't had a chance to obtain yet,
and to the work of Leonard Brand who looked at vertebrate footprints in the
Coconino Sandstone of the Grand Canyon. Art specifically recommended:
Brand., L. R. 1979. Field and laboratory studies on the Coconino
Sandstone (Permian) fossil vertebrate footprints and their
paleoecological implications. Palaeogeog. Palaeoclimat.
Palaeoecol., 28:25-38. (Reprinted in Benchmark Papers in Geology)
Brand, L.R. and T. Tang. 1991. Fossil vertebrate footprints in the
Coconino Sandstone [Permian] of northern Arizona: evidence for
underwater origin. Geology, 19:1201-1204. Commentaries on this
paper were published in: Science News, 141 (4):5, 1992; Geology
Today, 8 (3):78-79, 1992; and Nature, 355:110, 9 Jan., 1992.
Brand, L. R. 1992. Reply to comments on "fossil vertebrate footprints
in the Coconino Sandstone (Permian) of northern Arizona: evidence for
underwater origin." Geology, 20:668-670.
Brand, L. R. 1996. Variations in salamander trackways resulting from
substrate differences. Jour. of Paleontol., 70:1004-1010.
Brand, L.R., and J. Kramer. 1996. Underprints of vertebrate and
invertebrate trackways in the Permian Coconino Sandstone in Arizona.
Ichnos, 4:225-230."
Art has also previously (the entire posting is archived at http://
www.calvin.edu/archive/asa/199802/0006.html) mentioned Brand's work
and has stated that:
"Anyway, Brand has demonstrated convincingly that the trackways
were made subaqueously, so any further discussion on this point is
moot. There is no semblance whatsoever between tracks made on dry
sand and those made in the Coconino. I think we can safely move on."
If I may summarize Art's point, and please correct me if I'm wrong,
he is stating that Brand has rather convincingly shown, by his examination
of fossil trackways, that the Coconino Sandstone was deposited underwater
and therefore cannot represent a desert dune paleoenvironment as commonly
accepted by most geologists. This is therefore evidence for a global flood
(since he gave me these references in response to my question for such
evidence).
I've since read several of Brand's papers, and critiques of them,
and would like to make some comments:
First of all, for those who don't know much about the Coconino
Sandstone, a nice cross-section and description of Grand Canyon strata
may be viewed at http://www.kaibab.org/geology/gc_layer.htm. Note that
the Coconino is described as "petrified sand dunes" and view the pictures
of the vertebrate trackways commonly found within this unit. Note also
that there are thousands of feet of sedimentary rock beneath the Coconino
and hundreds of feet of sedimentary rock above it.
What did Brand do? Brand did some laboratory experiments where he took
salamanders - the western newt _Taricha_torosa_ - and examined trackways
they made in various types of sediment. Brand examined trackways in mud
and sand, on level and sloped (25 degrees) substrates, and in dry, damp,
wet, and submerged sediments. Brand concluded that fossil tracks seen in
the Coconino are most like the tracks made by his amphibians when they were
partially swimming and partially walking on the surfaces of underwater dunes
while drifting sideways by lateral currents (Brand and Tang, 1991). On this
basis, he reinterprets the Coconino as forming subaqueously (underwater).
Most geologists, on the other hand, have always interpreted the Coconino
as having formed as eolian (wind-blown) sand dunes (Middleton, et al., 1990).
There are a few points I'd like to make about Brand's claim.
1. Brand is employed as a professor of biology and paleontology in the
department of natural sciences (http://www.llu.edu/llu/grad/natsci/
brand/leo.htm) at Loma Linda University - a self-described "Seventh-day
Adventist educational health-sciences institution" (http://www.llu.edu/
aboutll.htm). I'll probably catch flack for this but it is true that
Adventists are generally required to believe in a global flood (it's
listed as a "fundamental belief" at http://www.sda.org/pages/
main_belief.html). While this doesn't mean that Brand's work should be
discounted (I've never met the man and have no idea if he is an Adventist
or not), it does mean, in my opinion, that his conclusions should be
examined in that light. What Brand is trying to show is that a formation
interpreted by virtually all geologists as eolian sands is actually
subaqueous and, quite frankly, I get suspicious when I see someone trying to
make a radical reinterpretation of something in science in such a way that it
would apparently support their religious beliefs. Even if you disagree with
this point of view, at least agree with me that it's not a sin to closely
examine another researcher's published work if you're skeptical of the
conclusions for whatever reason. That's standard operating procedure in
science (and even a part of some definitions of "science").
2. Remember when Art said that: " Brand has demonstrated convincingly that
the trackways were made subaqueously, so any further discussion on this
point is moot"? Brand (1996) himself wrote in the conclusion of a
recent paper that: "The data do suggest that the Coconino Sandstone
fossil trackways may have been produced in either subaqueous sand or
subaerial damp sand." See that little word "or" in that sentence? That
means these tracks could well have been formed in damp sand that was never
under water. Middleton, et al. (1990, p. 189), when discussing the
preservation of fossil trackways in the Coconino, suggested that: "The
mists and fogs that intermittantly are present in areas of coastal sand
dunes would provide a suitable means of dampening the surface." It does
also rain from time to time, even in the desert. This is hardly the moot
point that Art believes it to be and is, at best, still an open question
with alternative points of view supported by the data.
3. The mainstream interpretation of the Coconino as terrestrial was not made
only on the basis of the particular fossil trackways studied by Brand.
This is an important point. We must not look at only one piece of evidence
in order to interpret the environment of deposition for the Coconino. The
following information was summarized from Middleton, et al., 1990. While
there are no body fossils in the Coconino, there are trackways of at least
10 invertebrate ichnospecies and 16 vertebrate ichnospecies. Fossil tracks
similar to those left by modern-day tarantulas and wolf spiders have been
identified on the basis of experimentation (looking at spider footprints in
sand) and fossil trackways similar to those left by modern-day scorpions,
millipedes, and isopods have also been identified (and studies of these
trackways showed that the tracks would only be made if the sand was dry!).
With regard to all of the tetrapod vertebrate tracks, including those
identified as being left by synapsid reptiles, it's useful to remember that
these animals commonly live on land and not underwater. The sediment
comprising the Coconino (fine-grained, well-sorted, rounded quartz grains
with minor potassium feldspar) is compatible with eolian deposition. Small-
to large-scale planar, tabular, and planar wedge cross stratification
indicates eolian dunes. Wind-ripple laminations are present. Raindrop
impressions are found. For a detailed discussion of all of the features in
the Coconino that suggest subaerial eolian deposition, I refer the reader to
Middleton, et al. (1990), and the references they provide to the primary
literature. Taken together, the evidence overwhelmingly suggests that the
Coconino represents an erg, a "sand sea" in a Permian desert.
4. Details of the tracks examined by Brand and believed to demonstrate
swimming or floating of the amphibians may be interpreted in other ways
(Lockley, 1992; Loope, 1992). Once again, Brand may be correct in his
interpretation, but he has failed to convince other paleontologists since
there are alternative explanations that make more sense when looking at
the Coconino as a whole.
5. The Coconino tracks are not the only ones interpreted as terrestrial.
I refer the reader to McKeever (1991) for other examples of Permian
trackways demonstrated to be eolian with evidence for the occasional
presence of water (raindrop impressions, mudcracks, infiltrated detrital
clays) necessary to preserve the tracks. The Coconino tracks are not
unique features.
6. How on earth is this evidence for a global flood? Little salamanders
valiantly swimming for their lives while the raging floodwaters rise is
an interesting visual image but seems difficult to reconcile with reality.
Remember that there are thousands of feet of sedimentary rock below the
Coconino Sandstone. Young-earth creationist Steve Austin, for example,
believes that all of the Paleozoic strata within the Grand Canyon were
deposited during the flood (Austin, 1994, p. 58). A concise explanation
of how one can deposit the Tapeats Sandstone, Bright Angel Shale, Muav
Limestone, Temple Butte Formation, Redwall Limestone, Surprise Canyon
Formation, Watahomigi Formation, Manakacha Formation, Wescogame Formation,
Esplanade Sandstone, and Hermit Shale (thousands of feet of rock!), then
have little salamanders swimming around making footprints in the depositing
Coconino Sandstone would be interesting to hear since I cannot conceive of
how this could occur (unless, of course, one would like to invoke miracles).
No geologist would lose much sleep if Brand was correct and the Coconino was
subaqueous. Big deal, so are most other sandstones. It would not be evidence
for a global flood. Keep in mind that believers in a global flood cannot
allow any rock units within the stratigraphic record to be terrestrial since
that would effectively disprove their model that Phanerozoic sedimentary rocks
are flood deposits. Mainstream geology has no trouble accomodating both
terrestrial and marine deposited strata since it supports their thesis that
local environments have changed with time.
Bottom line. Brand's work is interesting and the type of work paleontologists
should be doing (and many are) in order to interpret trace fossils. But Brand has
not, by any stretch of the imagination or wishful thinking, "conclusively demonstrated"
that the Coconino was subaqueous. It's still possible to interpret these trackways
as being formed in damp eolian sands. Even if these are subaqueous, which is unlikely
given the trace fossil assembleges there, it would be shallow water and hardly evidence
for a raging global flood that had already deposited thousands of feet of sediment.
I remain skeptical since I believe the burden of proof to be on those proposing
radical reinterpretations of earth history.
I'm currently teaching historical geology and utilizing examples from the Grand
Canyon to teach students about various topics (unconformities, relative time,
transgressions and regressions, correlation, faunal succession, etc.) in both
lecture and lab. Nothing I've read in Brand's work convinces me that I'm misleading
my students.
REFERENCES
Austin, S.A. 1994. Grand Canyon: Monument to Catastrophe. Institute for
Creation Research.
Brand, L.R. & Tang, T. 1991. Fossil vertebrate footprints in the Coconino
Sandstone (Permian) of northern Arizona: Evidence for underwater origin.
Geology 19, 1201-1204.
Brand, L. R. 1992. Comment and Reply on " Fossil vertebrate footprints in
the Coconino Sandstone (Permian) of northern Arizona: Evidence for underwater
origin." Geology 20, 668-670.
Brand, L.R. 1996. Variations is salamander trackwas resulting from substrate
differences. Journal of Paleontology 70, 1004-1010.
Lockley, M.G. 1992. Comment and Reply on " Fossil vertebrate footprints in the
Coconino Sandstone (Permian) of northern Arizona: Evidence for underwater
origin." Geology 20, 666-667.
Loope, D.B. 1992. Comment and Reply on " Fossil vertebrate footprints in the
Coconino Sandstone (Permian) of northern Arizona: Evidence for underwater
origin." Geology 20, 667-668.
McKeever, P.J. 1991. Trackway preservation in eolian sandstones from the Permian
of Scotland. Geology 19, 726-.729.
Middleton, L.T., Elliott, D.K., & Morales, M. 1990. Coconino Sandstone. In:
Beus, S.S. & Morales, M. Grand Canyon Geology. Oxford University Press. 183-202.
-- Steven H. Schimmrich Assistant Professor of GeologyPhysical Sciences Department schimmri@kutztown.edu (office) Kutztown University schimmrich@earthlink.net (home) 217 Grim Science Building 610-683-4437, 610-683-1352 (fax) Kutztown, Pennsylvania 19530 http://home.earthlink.net/~schimmrich/