Re: Precambrian geology

Jonathan Clarke (
Wed, 24 Mar 1999 08:04:17 +1100

Hi Bill

Bill Payne wrote:

> On Mon, 22 Mar 1999 08:03:28 +1100 Jonathan Clarke
> <> writes:
> >Another way to ask these questions is "What unique features exist in
> >Cambrian to Carboniferous?Permian?Paleogene/Pliocene rocks that shows
> >they must have been formed in a global flood"?
> Good question. Maybe within the last year, I saw a statement by someone
> to the effect that Permian (?) coals were largely rotted, and therefore
> of poor quality. I think it was stated by that individual that if the
> same bacteria that degraded the Permian coals had evolved by
> Pennsylvannian time, there would be very few quality coal seams in the
> Pennsylvannian.

The university I currently have does not have anything like the literature
on coal that my old ones does. No surprising really, there is not a coal
mine within a bulls roar (and bulls roar loudly in the antipodes). So, from
memory, Australian Permian coals are probably fairly typical of Permian
coals in general (which are mainly though not exclusively Gondwanan). They
do have higher inertinite (charcoal) contents that those of the
Carboniferous, I can't recall what evidence there is for fungal activity.

> I may have the details wrong, but I remember thinking that another
> explanation would be that the Pennsylvannian coals were deposited out of
> water and quickly buried, whereas the Permian coals may have either been
> swamp coals or deposited out of water but buried more slowly.

Curious you should mention this. Up to perhaps 40 years ago, the
conventional interpretation was the other way round. Carboniferous coals
were generally interpreted as in situ and those of the carboniferous
transported. In the last 30 years however the Permian coals (in Australia
anyway) are more generally thought to have formed in situ as well. This has
been based on detailed studies of paleosols, etc., associated with them.
Some individual seams are still understood to be transported or subaqueous
however, although these are volumetrically minor. The book I referred you
to last year on Australian coal geology should have the details. Older coal
text books (60's and older) should have the old interpretation on Permian

Have you though further about my recognition of flood lithologies criteria?

> Bill

God Bless