From: Bill Payne (email@example.com)
Date: Tue Aug 13 2002 - 23:41:11 EDT
In response to the exchange at the end of this post, I wrote Jack Pashin
of the Geological Survey of AL:
>I think I remember you saying several years ago, I guess at a field
>that the Carboniferous coals were well preserved, but the Cretaceous and
>later coals were badly decayed by bacterial action. Do you agree with
>this concept or have I mis-remembered it?
>Also, if you do agree, to what do you attribute the difference in
>of preservation of coal?
With Jack's permission to repost, he responded as follows:
You remember correctly! Some paleobotanists think that a key
mechanism for preservation of Carboniferous peat is that
peat-degrading bacterial and fungal communities had not yet
developed. Of course there is still plenty of degraded material in
Carboniferous coal and plenty of well-preserved plant material in
younger coal. After all, this stuff did form in the real world.
The most obvious difference between the Carboniferous and younger
coal is the appearance of abundant fungal bodies in Permian coal. For
my $0.02, there is no shortage of evidence for active bacterial
communities in the Precambrian, but the appearance of abundant fungi
in Permian coal suggests that higher biological productivity was
required to outstrip biodegradation so that thick peat could form and
I think the simplest explanation is that the organics buried early in the
flood had less time to decay than those which floated longer and had more
time for fungal bodies to do their thing.
On Fri, 26 Jul 2002 04:58:36 -0700 "Glenn Morton"
> David Campbell wrote on Thursday, July 25, 2002 5:02 PM
> >A couple of additional considerations:
> >Not all plant biomass makes it into coal. Various organisms,
> >including certain bacteria, protists, and fungi can consume wood,
> >many others can digest less durable plant tissue such as leaves.
> >Lignitized wood from the Mesozoic and Cenozoic commonly is full of
> >holes from shipworms and other wood-boring bivalves (which have
> >symbiotic bacteria and protists to digest the cellulose). This
> >raises the question of how long the wood had to sit exposed on the
> >seafloor for the shipworms to make their holes, which can raise
> >problems for flood geology models.
> This consumption also raises the quantity of plant matter which must
> the first place to account for the coal we see. Thus in the
> presented the other day, if half of all wood is eaten, one must have 2
> world's full of tropical rain forests.
> >A variety of coal deposits are not currently economical to mine and
> >may be omitted from some databases. Don't forget the Triassic rift
> >valley coals in the Atlantic coast states and the Cretaceous coals in
> >the Plains (in Canada and the U.S.) in calculating total volume.
> The quantity of coal in John Hunt's work is all in the world, including
> seams. The BP Statistical Review of World Energy reports that the
> of coal are around 1/15 of the total quantity Hunt reports. For those
> don't know what reserves are, they are the amount one can economically
> out of the ground.
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