> The "Cambrian Explosion", instead of being explosive diversification, is
> explosive sedimentation.
and...
> Again, their lower stratigraphic position of entombment does not
> necessarily prove an earlier date of origin, life, or death.
and...
> Well, we have a lot of data out there, and it accords with the hypothesis.
> The major issue in testing it is determining how fast and deep the Cambrian
> and other Phanerozoic sediments came in. Clearly it was fast and deep
> enough in many areas to exclude much bioturbation. Also in some areas
> excluding diffusion of oxygen (stopping decay and enabling considerable
> detailed preservation). And geologically, there is abundant evidence of
> rapid sedimentation.
It's clear you're simply proposing the standard young-earth creationst
position regarding Noah's flood (without explicitly worrying about the age
of the Earth but I understand that SDA geologists are flexible on that).
There are numerous substantial geologic problems with the idea that the
sedimentary record is evidence of Noah's flood.
Let me just list 5 problems (want 25? 50? I could list them):
1. The distribution of brachiopods vs. bivalve molluscs in the
stratigraphic record. There is little difference between these
two groups in terms of hydraulic sorting or ability to escape
rising flood waters. How do you explain the observable fact
that brachiopods are extremely numerous and diverse in Paleozoic
strata while becoming much more limited in range and diversity
after the Permian extinction while bivalves show the opposite
pattern? How do you explain the appearance worldwide of certain
brachiopods, for example, which only occur in, say, Devonian
strata (I can look up some specific species if you like).
2. The occurrence of igneous plutons and batholiths within Phanerozoic
sedimentary strata of such a size as to require, using standard
thermodynamic calculations, that the bodies would take tens of millions
of years to cool (depending upon their size, of course). How does
one have rapid sedimentation with a thick gabbroic sill in the middle
of the package of sedimentary rocks?
3. The occurrence of ichnofossils (trace fossils like burrows, tracks,
coprolites, root casts, etc.) seems difficult to understand in the
context of a global flood with rapid sedimentation. How does one
deposit thousands of feet of sedimentary rock in a violent flood
and then form a sandstone bed with dinosaur tracks on it? Or develop
a paleosol? What about a limestone on top of thousands of feet of
flood deposits containing an in situ coral reef with associated
fragile crinoids or bryozoans preserved as well?
4. How does one get thick halite (salt) or gypsum layers in the middle
of Paleozoic sedimentary rocks? How exactly do evaporite minerals
form in flood waters? Oh, and also please explain mud cracks, scour
channels, and ripple marks in adjacent shales to some of these
deposits (I have photos from a gypsum mine under Grand Rapids if
you'd like to see them). Since you mentioned rapid sedimentation,
please explain how long it takes to precipitate, say, 100 feet of
halite from flood waters. How much heat would be released by such
a rate?
5. How does a global flood explain angular unconformities? I can, for
example, direct you to an outcrop along a railroad bed in southeastern
Pennsylvania showing one mile of east dipping turbidite deposits
(with hundreds of graywacke/shale packages) abutting against vertical
quartz arenite sandstone beds. Please explain how features like this
form by rapid sedimentation in a global flood.
I'll be anxiously awaiting your reply.
- Steve.
-- Steven H. Schimmrich Assistant professor of geology Department of Geology, Geography, sschimmr@calvin.edu (office) and Environmental Studies schimmrich@earthlink.net (home) Calvin College, 2301 Burton SE 616-957-7953, 616-957-6501 (fax) Grand Rapids, Michigan 49546 http://home.earthlink.net/~schimmrich/