Re: coal again!(1)

Jonathan Clarke (
Tue, 30 Mar 1999 20:33:56 +1000

Hi Bill

Once more to the breach dear friends....

Bill Payne wrote:

> On Mon, 29 Mar 1999 06:49:47 +1000 Jonathan Clarke
> <> writes:
> >At the risk of repeating myself, coals potentially deposited by a mix of
> >processes. If you have good evidence and can convince other people of
> it, I
> >have not problem. I am sceptical because other people writing on
> similar
> >coals see different things.
> Bob Gastaldo and I seem to see the same thing, at least as far as his
> 1984 paper goes. The divergence comes in our interpretation of what we
> see, and our interpretation is strongly influenced by our paradigm. I
> think my exchange with Keith illustrates this.
> >> >the weight of opinion should always count for something. Of
> >course, you
> >> might be >right for individual seams. Maybe you are right about
> >the
> >> seams you are talking about.
> >>
> >> You don't want to go there.
> >
> >What do you mean by this?
> Sorry, I guess that's an American expression. If you grant that I am
> right about the seams I am talking about, and if these seams have
> characteristics in common with Carboniferous coals in general, then the
> allochthonous interpretation will sweep a very wide path - far beyond the
> particular coals I am talking about. By saying "You don't want to go
> there" I meant that the paradigm I think you work within would be
> weakened. It was/is irrelevant to our discussion. My apologies.

Thanks for the explanation. I believe it was Churchill who wrote about one
people divided by a common language.

> >
> >> The seams I am talking about are not atypical. If I am right about
> the
> >> seams I am talking about, then there is something very wrong with the
> big
> >> picture (uniformitarianism).
> >
> >I am afraid you have lost me completely. If you are right about the
> seams
> >you are talking about, you are right about those seams. You will have
> >successfully defended one model of coal deposition for a particular
> seam, and
> >falsified others. This sort of thing goes on all the time in geology.
> It
> >says little about the formation of coal in general. So why do you say
> that
> >this implies there is something wrong with "the big picture
> >(uniformitarianism)? Since when have we been discussing
> >uniformitarianism?
> >So, if I read you correctly, you are saying here that originally you
> favoured
> >YEC because of your Biblical hermeneutic. Now you feel you have
> evidence, on
> >the basis of a number of coals, that the geological record supports a
> young
> >earth. So your belief in a young earth is now based on geological
> evidence,
> >which reinforces your understanding of Scripture. Am I right?
> Halfway, maybe. I really am not concerned with the age of the earth, and
> I fully recognize that there are other geologic problems with the YEC
> model. I do believe in a literal Adam and a worldwide flood, and, no, I
> cannot explain all of the problems from a scientific POV w/ what I
> believe.

To me this sounds like you are arguing mainly for a reinterpretation of coal
facies rather than a whole scale adoption of flood geology. Is this correct?

> >We make progress! Therefore, if the structure of a Biblical passage
> >suggestions that is is figurative, then you would agree that it is
> likely
> >that the authors intention was that it should be understood
> >figuratively?
> OK. I don't know what I'm opening myself up to here, but OK.

Nothing at this stage - just clarifying!

> >Thanks for clarifying this. So you haven't actually seen the Pittsburgh?
> No, sorry if I implied that I had.
> >> Not according to Gastaldo.
> >
> >No comment until I have read Gastaldo. However I am interested that you
> are
> >citing him in your defense. I thought you disagreed with him? I notice
> that
> >Keith Miller made almost exactly the same point.
> I disagree with Gastaldo's conclusions, not his observations. Bob was
> attempting to discredit Austin's floating mat model for coal formation.
> In building his case, he stated that these trees were heavy and that the
> roots went deep:
> "Although speculation continues as to the
> textural character of these trees, the fact that specimens have been
> documented in excess of 38 meters in height attests to the
> interpretation that these trees were not frail or lightly built. None
> of these characters supports the contention of a reduction in weight
> allowing for a floating habit."
> "Morphological considerations suggest that these plants were adapted to
> extreme swampy conditions, and the disposition of the stigmarian axes
> within various lithologies can only be interpreted as recording growth
> in situ. The variable angle of axial penetration and their
> crosscutting relationships, the helical and undisturbed arrangement of
> the 'rootlets', and the abiotically undisturbed sediment surrounding the
> axial/appendage system, lend support to their autochthonous character."
> In arguing against Austin's floating mat model by saying that the trees
> were heavy and that the roots went deep, Bob inadvertently supported
> (IMHO) allochthonous coal since coal seams do match his statements. Bob
> was attempting to show that the floating mats could not have been living
> mats (with the trees growing in/on the mats) as Austin I think originally
> envisioned. I think the mats consisted of organic debris rather than
> living trees in upright position on the mats.
> >As I keep saying, I have a sceptical but (I hope) open mind on your
> coals. I
> >also keep stating that I do not have one model for coal, but a good half
> >dozen. Not all are autochthonous. You, however, do seem to be wedded to
> >single model for all coals.
> Yes, for all Carboniferous coals, at least in the eastern US. This is a
> product of my flood model, which, if correct, would encompass all of
> these coals with a single depositional event, and a product of my
> understanding that all of these coals display similar features. The
> description of the Pittsburgh matches perfectly with what I see in
> Alabama. I do appreciate your skepticism and willingness to keep an open
> mind. I hope I can do as well.
> >I don't see your point. What box are you talking about? Where are the
> large
> >roots if not directly beneath the coal?
> Ah, we make more progress. The large roots I have seen are in the rubble
> along with large tree trunks. In other locations I have seen vertical
> tree trunks directly beneath coals. I have seen the bottom end of at
> least three trunks, and none of them had roots, suggesting that they had
> possibly (my interpretation) been sheared off, floated into vertical
> position, settled to the bottom and buried within a relatively short
> time. I believe that since the large roots are in the strata associated
> with coal instead of being directly beneath the coal, then the large
> roots also floated in with the trunks from which they were detached.

If correct, this could be an important observation. You need to document the
proportion of stumps which have this feature to see whether it is an isolated
example or a general characteristic.

> I wrote and asked Bob Gastaldo where the Stigmarian axial root photograph
> in his paper was in relation to the Upper Cliff coal, located in Blount
> County, Alabama. I had driven to the site and looked at the coal seam,
> hoping to see these stigmarian axial roots (the big ones). When I saw
> nothing but the same features I had seen in many other coal seams, I sent
> Bob a cross-section of the pit highwall and asked him where in relation
> to the coal seams was the stigmarian axial root pictured in his paper. I
> also asked him to located the root on a topo map so I could see it for
> myself. Bob responded by saying it had been years since they had worked
> in that area, and wished me luck. The photo of the stigmarian root is
> not associated with a coal seam as it should have been to support his
> thesis.
> >Point it out for the slow brains like myself.
> Forgive my arrogance, you are certainly not a slow brain. Did the
> previous paragraph help?

Thank you yes. I am not surprised you could not locate it. Trying to
locate specific features on old mine walls is always dicey. They are such
dynamic environments. Active mines are worse. Stand still for 5 minutes and
you get run over by a haulpak.

> >Without a geological dictionary to hand, traction currents are those
> which
> >drag coarse silt, sand and gravel (by creep, saltation etc.) to their
> resting
> >places, as opposed to those which hold such sediment in suspension by
> water
> >turbulence. Most fluvial and shallow marine physical sedimentation is
> by
> >traction currents of one sort or the other.
> I should have remembered that. I do see impurities in coals. Because
> they are generally thin and widespread, I think they are the result of
> turbidity currents rather than traction currents.

So your mineral matter consists of fine-grained sediments. Are they
dispersed or as thin partings? Either way, a better way to describe
deposition of fine grained sediments would be by settling from turbid water.
Turbidity currents are a specific depositional processes with generally very
easily recognised features (e.g. Bouma sequences). I assume you don't mean

> >
> >I have seen erosion by overlying sediments in the Eocene, Triassic, and
> >Permian. I gather they are also well documented in the literature of the
> >Carboniferous
> I have seen this over some coals, but I don't see how this supports
> autochthonous coal. What was your point?

Erosion might well smooth out any topography at the top of the coal surface.

> >Coal is best studied on polished blocks typically with oil immersion.
> Coal
> >bearing sediments are best studied using thin sections. Polished thin
> >sections are a good compromise. I have used both thin and polished thin
> >sections to study coaly strata.
> >> The underclay should look like a topsoil which is black at the surface
> >> (from rotted roots) and gradually transitions to native, inorganic
> soil.
> >
> >This is what I think I see beneath coal beds, although the transition
> occurs in mm to cm.
> Interesting, I'm not sure I've ever seen that. If the transition is only
> mm to cm, this still seems too shallow for a root system as described by
> Gastaldo.

If you look at modern peats and soils, roots do extend to varying depths
below the zone of organic accumulation. So the transition zone zone does not
extend for the full depth of root activity even in the substratum.

> >>My impression was they were truncated at bedding
> >> planes about 6 inches apart beneath the coal. I would like to think
> that
> >> they may have floated in.
> >
> >With the matrix as well? Or has that come in later?
> If I understand your question, the roots and sediment were deposited
> together I believe. The alternative would be that the vegetation was
> still alive and sunk shallow roots in an effort to get a toehold before
> it was buried by more sediment. I suppose this might have gone on all at
> once, with plants sending down roots as they were being smothered by more
> sediment.

How fast do you think plant roots grow? They would have to grow awfully fas
in your scenario. Also floating wet vegetation is not very buoyant, and its'
capacity to raft significant thicknesses of substratum would be limited.
Vegetation rafting I have seen in rivers and estuaries can transport pebbles,
sand grains, and even the odd clod, but not entire substrata.

> Bill

Thanks for all this. I am trying to think where we can go from here. As I
understand you, your position is that the Carboniferous coals you have seen
were transported into place. On this basis you feel that all coals are the
result of transport, rather than in situ growth.

My position is that I have to keep an open mind, as I haven't seen your
rocks. However I also note that all the dozen or so papers I have read on
Carboniferous coals in the eastern US all appear to give good evidence for
them being formed in situ. I am happy to acknowledge that some coals might
transported, but most of the ones I have seen appear to be in place.

So where does this take us? I have three questions for you.

Given that modern peat deposits are known, and that the largest of these
overlap on size economic coal deposits, do you acknowledge that at least some
ancient coals are in situ? If not, why not?

Modern peats composed largely of transported material are known and their
characteristics documented. If it eventuates that most ancient coals are in
fact transported, how does this advance the cause of flood geology?

So finally, how important is this issue to your sympathies for flood
geology? If you saw good evidence that transported coals were part of the
actualistic range of coal depositional processes, or good evidence that they
did in fact form in place, what effect would this have on your support for
flood geology?

God Bless