Bill in a recent post (June 6th) you said: "Glenn, please compare the
drawing of a paleoswamp at
http://www.dcnr.state.pa.us/topogeo/pub/lop.pdf with the photos of the
chunk of coal you posted at
http://www.glenn.morton.btinternet.co.uk/CoalClose-up4.jpg
http://www.glenn.morton.btinternet.co.uk/CoalClose-up1.jpg This chuck
of
coal shows horizontal (planar) structure, which in outcrop may extend
for
feet, yards, and even miles. Forget, for the time being, the lack of
vertical trunks and roots in my photos; just concentrate on the planar
structure in the coal and explain how you can get a plane from the very
irregular topography found in a paleoswamp such as the one referenced
above.
Compression by 3 to 10 times to get coal from peat WILL NOT flatten out
the irregularities in the bottom profile of a swamp. How do you explain
the flat structure in coal such as the chunk in the photos?"
Bill,
I can't take more than a minute to reply. As you know from previous
exchanges, I have spent a number of years studying the spores in coal
and trying to make sense of the vegetation patterns.
Let me say that you are right in observing that often times coal has
top and bottom contract that are very flat. Although there also coals
that will sometimes grade into a
dark roof shale. Let me also say that the flat and very widespread
nature of some of the beds in the Pennsylvanian of the midcontinent are
interesting and may not fit nicely
into some expectations we might have from temperate US vegetation.
But:
1. Is the model of rafted peat any better for explaining a sharp
contact between coal and the clastic layers? You almost seem to
assume that in the current geological models that we are assuming that
the forest was buried upright. There are some examples of this, but
usually the assumption is that the swamp dies out and that most likely
you are burying rotten vegetation. To check this out you should compare
coal is an old lobe of the Mississippi delta or a modern swamp that is
producing peat and would not in your model be produced by the flood. If
the lithology is quite different you can build a better case. I don't
think it is but it might but it would be worth checking out.
2. You simply must show that you have read Cohen, Fisk and some of the
others who have studied modern peat development. It makes your case
much stronger to be aware of the literature. Of course MOST geologists
have not read them, but most geologists aren't talking about coal
formation and you are. I know you have read some of the literature and
with that little background are probably ahead of most of the ASAers on
the list - but it takes a lot more work on literature background if you
are going to try and change people who study coal formation or
environment of deposition. You also have the advantage of having looked
at real outcrops and not dealing with stratigraphy (rock layers)
secondhand or from a book.
3. Work in some other areas to show how your model give at least as
good explanatory power for real sedimentary features. That with a
showing of a grasp of the relevant literature will help your case
greatly.
4. Don't give up we need thinking folks of a different perspective
trying different paradigms.
I must run now. I only read the ASA list from the archives so if you
want an immediate response send it to me via e-mail.
bcc (so his e-mail is not on the net) to a colleague
James Mahaffy (mahaffy@dordt.edu) Phone: 712 722-6279
Biology Department FAX : 712
722-1198
Dordt College, Sioux Center IA 51250
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