Welcome to the fray!
> Karen J. said>> The many tracks and burrows higher in the column are also
>fascinating -- like the famous amphibian tracks in the Coconino sandstone.
>Why would you think there
>would be no amphibians left alive after the first few minutes or days of
>the onset of a flood? Animals that float don't mind how many thousands of
>feet of sediments are being deposited
>below them. <<
>
> Just to adding to what Steve S. has said already...
>
> A few more problems with this scenario:
>
> 1) Just a nit, the identification of the tetrapod track makers as
>amphibians is far from universally held.
>
Right. They call them amphibian or reptile. I just use amphibian for
short, and also because in lab experiments comparing trackways (in dry,
crusty dry, wet, very wet, and underwater sand), amphibians are easier to
use.
> 2) Tetrapod tracks are NOT the only animal tracks found in the Coconino.
>The Coconino also contains the tracks of several different kinds of
>arthropods and other invertebrates.
>
As might be expected.
> 3) The Coconino also contains other sorts of trace fossils most notably
>raindrop impressions.
>
> Even granting the tetrapod tracks are those of an amphibian (a dubious
>assumption), how do you explain the invertebrate tracks and raindrop
>impressions under the flood scenario? Did the spiders & scorpions happily
>bob about in the waves along with the 'amphibians' waiting for a chance to
>sink to the bottom and make footprints and then swim away?
>
Some of the tracks were clearly underwater. That doesn't mean all of them.
With no body fossils, it's hard to be sure exactly what kind of tetrapod
made the large (1-2 cm) tracks. Is it any easier to tell exactly what
kinds of arthropods or other animals made the invertebrate tracks? But I
can see how a person who believes that the dunes were subaerial might
(understandably) assume that they were tracks of subaerial invertebrates
such as spiders and scorpions.
> If this material was deposited rapidly how is it that no unlucky, stupid,
>or already dead animals managed to get buried in it? IOW why *only* trace
>fossils in the Coconino?
>
That is a big question, whether it was deposited rapidly or slowly,
subaerially or underwater.
> And just where did the uncounted millions of tons of well sorted, rounded
>quartz grains come from to create this deposit? A cosmic dump truck?
When I think of other large sandstone deposits, like the St. Peter
Sandstone (extending over many states across North America, with
well-sorted rounded grains, and no fossils) I wonder about the possibility
of gigantic aquifers broken and spilling out masses of sand. I don't know
the source area for the Coconino sandstone. If it was pre-existing dunes,
where did their sand come from?
Then
>of course there is the question of how the flood managed to sort not only
>all the animals taxonomically but how it managed to sort the materials that
>make up the various rock strata both physically and chemically. A series of
>cosmic dump trucks?
>
Are you referring to the entire Grand Canyon series here? Or more?
Clearly there were many different source areas. It's interesting that the
predominant paleocurrent direction of most of the formations in the Grand
Canyon trends from NE to SW. Doesn't it make you want to see a time-lapse
movie of what actually happened!
> How do relatively delicate trace fossils even form in a global - washing
>machine - flood scenario?
>
Washing machine? Like a blender that mixes everything together all at
once, then lets it all settle out? That's not my model! Delicate trace
fossils would be formed only where they were preserved before
disintegrating -- with sediment coarse enough to fall through the water
column but fine enough to cover them gently. Slow enough to be gentle, and
fast enough to cover the prints before currents destroy them.
> All these things, reptile/mammal-like reptile tracks, spider & scorpion
>tracks, the lack of body fossils, a sandstone made up of well sorted,
>rounded quartz sand is perfectly consistent with a desert eolian sand dune
>environment.
>
You believe that? I saw a diorama of that at a Grand Canyon visitor
center, back in the 60's. That was before they knew very much about large
submarine sand dunes, and ambulatory behavior of amphibians underwater, and
the fact that the fossil tracks match underwater prints much better than
dry, crumbly, wet or very wet sand ones.
> Why should anyone who is not defending a literalistic interpretation of
>the Bible, accept the rather bizarre flood model for the origin of this
>formation over the straightforward one?
>
Why? Because the tetrapod tracks, invertebrate tracks, lack of body
fossils, and sandstone made up of well-sorted rounded quartz sand is
consistent with a submarine sand dune environment.
Karen