Re: US Pennsylvanian Coal - depositional setting

From: Bill Payne <bpayne15@juno.com>
Date: Wed Apr 14 2004 - 00:08:44 EDT

Hi Kevin,

There are a couple of things in this post that I don't think I ever
responded to. I'm working my way back to your March 10 post referenced
below.

On Wed, 17 Mar 2004 07:01:53 -0700 "Kevin Sharman" <ksharman@pris.bc.ca>
writes:

> Bill, you must not have read or understood my post of March 10th
showing how
> thin tephra layers in Recent peats were undisturbed, despite
> re-establishment of peat growth above them. This directly refutes your
> long-standing insistence that bioturbation by roots would destroy a
thin
> layer.

I disagree, but will respond in a separate post.

> The example shows that the substrate doesn't have roots when they
looked at
> it. The real question is "Did the substrate ever have roots?" In
other
> words, did the substrate have roots when the peat was being
established, the
> roots bioturbated the substrate, and now they are not visible, or did
the
> peat establish without rooting of the substrate? If you say that the
roots
> were there, and now they're not, I will use this to explain ancient
examples
> of substrates with no roots. If you say the roots were never there, I
will
> use this to back up my contention that the roots didn't need to
penetrate
> the substrate. Your modern example isn't helping you.

To say "that the roots didn't need to penetrate the substrate" ignores
examples I have photographed of grass and trees with roots which
penetrate the substrate. Some of these are coming your way tonight.

I say the roots were never there, and you say you "will use this to back
up my [your] contention that the roots didn't need to penetrate
the substrate." You may say whatever you wish, but you are running
counter to my photos when you say "roots don't need to penetrate the
substrate." Roots, grass as well as tree roots, do penetrate the
substrate - for nutrients and for support, even in the flooded conditions
of the swamps I have photographed for you.

> > Would you agree that these rootless
> > coal seams are allochthonous?

> In a word, no. See my discussion above about lack of roots below
seams.
> The seams with no roots could be hypautochthonous, with peat
transported
> within the swamp. If this is the case, they should be high in mineral
> matter and inertodetrinite. Or they could be from the attached
floating
> mats Glenn mentioned. These appear to be of limited extent, as they
> normally fringe the edge of lakes and abandoned channels, and they can
be
> considered in situ (not transported).

How many square miles would rootless coal seams have to cover before you
would admit that they are not of "limited extent"?

Bill

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Received on Wed Apr 14 00:15:37 2004

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