You wrote:
> 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).
>
>
This would be a problem hydrologic sorting or ability to escape rising
flood waters were the only factors influencing the order of fossils.
Another probable factor is original distribution. We don't know the
original distributions, but do know that brachiopods and mollusks are not
equally distributed today. They were not necessarily equally distributed
in the past.
> 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?
Glenn has shared some of his calculation on this, and others have offered
alternative viewpoints. I am no geophysicist, but I know that water
conducts heat well, and there are many earth processes that require
tremendous amounts of heat. Clearly the oceans have not boiled away in
the past. The marine environment has been stable enough to maintain life,
despite extensive extinctions. And land areas (if they took tens of
millions of years to cool, would they be devoid of life all that time?)
have supported its biota as well. I don't think we have all the answers
about heat balance.
>
> 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.
They seem difficult to understand in the context of slow sedimentation,
too. If seafloor sedimentation were gradual, tracks and burrows would be
quickly destroyed by continuing bioturbation. The presence of tracks, etc.
indicates quick preservation before disintegration.
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?
When the tide goes out, wouldn't one expect the remaining dinosaurs to make
tracks where they could?
Or develop
> a paleosol?
Are you convinced that the silty layers called paleosols were actually
formed slowly, then preserved in situ (usually with no unconformity)? I
am not. Even those with root casts in them are not necessarily slowly
formed. If they were the roots would have decayed. Even vertical
petrified trees in growth position are, on closer inspection, by many
evidences, found not to be in growth location.
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?
In many such reef structures the fossils are not really organically bound,
but are suspended in the matrix. Capitan Reef, for example, has been
recognized as a gigantic debris flow. Some reefs that show organic
structure are oriented upside down. They were probably transported from
where they grew -- which would suggest high-energy water movement. The
reef problem is very interesting.
>
> 4. How does one get thick halite (salt) or gypsum layers in the middle
> of Paleozoic sedimentary rocks?
How do you get halite layers on the surface? They are usually not pure
halite, and not very thick. You would have to evaporate many feet of sea
water to get layers like we find in the column, and it wouldn't be pure
halite -- or pure gypsum.
How exactly do evaporite minerals
> form in flood waters?
I don't pretend to know exactly! To get pure deposits, you would have to
have pure precipitates from pure brines. Brines still come out from the
ocean floor. Temperature changes and other factors induce supersaturation
and precipitation. This suggests some interesting experiments.
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).
I would expect scour channels and ripple marks (and other paleocurrent
indicators). Are the mud cracks in the same area? Mud cracks do form
underwater by chemical shrinkage.
Since you mentioned rapid sedimentation,
> please explain how long it takes to precipitate, say, 100 feet of
> halite from flood waters.
I don't know how rapid. But if it were slow, even mm per hour, I would
expect a lot of impurities in it. The purity we observe would indicate
to me a much faster rate.
How much heat would be released by such
> a rate?
>
Is the amount of heat affected by the 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.
First I have to ask you how a mile of turbidite deposits with
graywake/shale packages
could form slowly? If these are anything like the Great Valley Sequence
(in NW California, which I studied during PhD research) they show little
evidence of time between turbidites -- so little that there is hardly any
bioturbation (but a few examples, showing that organisms were alive in the
area, and some fossilized, during the deposition), and no signs of erosion
between layers. To me, this (and other observations) speaks of rapid
deposition of the turbidic sequence, which was later tilted (in the case of
the GVS the tilting was part of seafloor accretion to W. North America).
How much later? I don't know. Long enough to dewater and set the
limestone well enough to keep its integrity (hours, days?) , but not so
long that the layers were indurated so much that they would shatter upon
tilting or folding (i.e., not months or years). There are some places with
folded strata.
Such tilted turbidites abutting against vertical quartz arenite sandstone
beds ! Any evidence of overthrusting? Must have been some dramatic
earth movement there! How do you read it?
>
> I'll be anxiously awaiting your reply.
>
As I am yours.