At 06:50 PM 10/26/97 -0600, bpayne@voyageronline.net wrote:
>Glenn Morton wrote:
>> Won't work. Even the most optimistic compaction factor for shale (that
>> shale has 80% initial porosity and compacts to 15% porosity) This would
>> still leave a 500 foot hill across the plant matter which is destined to be
>> coal.- see Well Log Interpretation Techniques, Dresser Atlas,1982, p. 160
>> and Dickas and Payne, AAPG June 1967, p. 879)
>
>There is a way to test for differential compactions of shale and coal.
>If we can find a tree buried diagonally through underclay, coal and
>shale, the tree will be bent, assuming differential compaction, as it
>passes from one rock type to the other (similar to the way light is
>refracted as it goes from water or glass to air). If anyone is aware of
>an expample of this, please let me know. You may be right, Glenn, but I
>would like to see empirical confirmation.
That might empirically test the idea, but I know of no example. One thing I
forgot to mention, if you had clay, initially suspended with 80% initial
porosity and try to deposit a layer of sand on top of it, the sand will
plummet into the shale but not into the pile of plant matter. A layer of
clay particles with 80% porosity doesn't have the strength to support heavy,
dense sand.
I cite Reineck and Singh, Depositional Sedimentary Environments, Springer
Verlag, 1980, p. 330. They are speaking of the Mississippi River's river
mouth bar sands being deposited on the relatively unconsolidated pro-delta
shales. They say,
"Continued development of sand bars are the mouth of the distributaries as
the delta advances seaward produces elongated sand bodies. such sand bodies
tend to sink into the muddy prodelta sediments, and sand bodies thicken.
They can be > 90 m thick, 7.5 km wide and extend over a distance more than
50 km. In cross section bar finger sands exhibits a typical bioconvex form.
Because of compaction of the prodelta muds, they also intrude into sand
body as mud diapirs; and are sometimes even exposed at the surface."
We see this phenomena at river mouths, but I never saw mud diapirs in that
uniform thickness sand covering the coal up at the Lee/Bastrop co. line.
What this means is that the shales I worked with were already more compacted
so that they could support the weight of the overlying sand. and the more
compact the shales were, then the greater is the mountain the plant material
must make.
In my book I have a picture of a highly organicly rich shale. It was nearly
a coal and was taken from an oilwell core. The core was taken from a well
in SE Colorado from (this is from memory) 7000 feet (I am too lazy to look
in my book). It shows 10 layers of roots over a 3 inch core. The roots
truncate at layers above, but occasionally can be followed through a lower
layer. It looks something like this:
top
----------------------
| | |
| |
-----------|-----------
| | |
| |
----------------|------
| | |
| |
---------|-------------
bottom
This is a very difficult thing to explain based on a global flood. The roots
should be a jumble but they look like they grew downward into the lower
layers but never upward into upper layers. Over a 3 foot section of this
highly organic layer, there were approximately 250 layers like this. It has
the appearance of an oxbow lake deposit. And 7000 feet down in SE Colorado
is in the middle of your global flood. How does a global flood produce a
deposit that looks like plants grew over a period of years?
>
>> >But the real question we should be asking is not the objections you've
>> >listed above, but: Is there a way we can in fact determine if coal is a
>> >flood or a swamp deposit?
>>
>> But who cares? If coal is formed from floating vegetation mats as Austin
>> claims so what? I can think of a bay protected by barrier islands (like the
>> Laguna Madre of Texas) with a floating mass of vegetation on it to account
>> for coal in that fashion. If coal is not a swamp deposit it doesn't hurt
>> uniformitarianism at all.
>
>That's a fall-back position which most of the geologists I know fight
>tooth and nail, because (I think) of the potential support allochthonous
>(floating mat) coal may lend to the Flood.
But Bill, if you wish to influence some one on an issue of great importance
to them, you have to find a battle ground where there is no fall back
position. You can't leave any out. Even then you must wait a long time
before they will change. By fighting the battle you do on coal, you are
wasting your time. Even if you are correct that coal is not a swamp
deposit, then you haven't really accomplished what you wanted to.
>The larger question is, if
>coal has been mis-interpreted by so many for so long, what other
>theories, based upon more tenuous data, also need to be reevaluated?
This is a logically flawed epistemology. Because I mis-interpret one item
does not mean that everything is mis-interpreted and therefore all knowledge
must be held in abeyance awaiting reevaluation. You don't even live
according to the above dictum. If you decide that you have mis-interpreted
a Bible verse, does this mean that you must now reevaluate every one of your
theological positions because they are based upon tenuous data??? If you
don't do this, why would you expect the geologist to do this?
glenn
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm