Re: coal again!(1)

Jonathan Clarke (
Mon, 29 Mar 1999 06:49:47 +1000

Hi Bill

Bill Payne wrote:

> With the little time I have, I will try to do justice with your excellent
> post.

Thank you.

> I see exactly what you describe. I don't see anything about these
> features that suggests autochthonous processes.

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.

> >Which coals have you examined?
> I've looked at probably several dozen seam outcrops or exposures in north
> Alabama, and several of the Kentucky seams which Steve Austin studied
> when I joined Steve and his students while they were on a field trip.
> The only difference I have noticed in the seams is that some have no
> rootlets below and some do; otherwise they are rather monotonous.
> >What features lead you to think you are
> >mistaken? How confident are you in your own observations?
> Very confident. My strength is field geology, mapping and synthesis of
> data.
> >Last year you
> >hadn't recognised rootlet horizons, one of the simplest and most
> important
> >things to look for in any succession of coaly sediments. I don't want
> to
> >sound too critical here, but what else are you missing? Other
> geologists had
> >known about roots etc. beneath Carboniferous coals for over 100 years.
> Yes, but I was looking for roots that would support tall trees - the type
> described by Gastaldo. In his paper, Gastaldo included a picture of a
> stigmarian axial root system. What I had observed beneath coals was tiny
> carbonaceous ribbons, which look more like grass roots. Now that I have
> recently seen what the stigmarian axial root systems really look like, I
> realize that I was looking at rootlets. It is important to note that
> large root systems and stumps are found _associated_ with these coals in
> B'ham, but not in the strata immediately below the coal (for the large
> roots) and the stumps are not in the coal seams - where they would have
> to be if they formed the coal in situ.
> >Unless they others are all idiots,
> No, these are very intelligent men.
> >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?

> 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?

> >Thank you for being so honest. So let me ask you another question. If
> it
> >were not for this hermeneutic, would you really feel pushed towards the
> >position? Or would you be comfortable with the geological evidence for
> an
> >old earth?
> At this point I'm not concerned about the age of the earth, just coal.
> The hermeneutic (and Steve Austin) prompted me to look for myself, having
> seen the fit of the data, I no longer need the hermeneutic.

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?

> >If you don't want to take Genesis 1-3 figuratively, that is fine, so
> long as
> >you acknowledge that the Church fathers and the Jewish rabbis thought
> >differently. Gordon Brown has pointed out the most likely way Jude 14
> was
> >meant to be taken.
> OK, so maybe instead of Enoch being the seventh, maybe he was the tenth
> from Adam. But I still don't see a case for making Adam 250,000 years
> ago, nor for making the flood local.
> >We have to be careful about what we mean by the word "literal". The
> literal
> >meaning is the actual meaning, the meaning that the author intended.
> Agreed.

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?

> >The other interpretation is that it represents a catastrophic collection
> of
> >floating plant debris.
> This is the model I envision.
> >I have seen rafts of this type on rivers, shorelines
> >and in the geological record.. But they don't have the density of
> organic
> >mater to form coal. Such agglomerates of plant debris are also quite
> weak
> >structurally, and it is hard to imagine a raft of that size forming in a
> >turbulent environment. They could survive in a low energy environment.
> But
> >when they sink their relatively low organic content would not result in
> them
> >forming coal, only a wood rich sediment.
> That would depend upon the relative rates of organic and inorganic
> settling rates.

Such deposits I have seen and read about all have a matrix that would not be
classified as coal on lithification. Not even those in Spirit Lake.

> >I like the following section, because in it you mention specifics. You
> need
> >to be more specific though. Which coals are you referring to in it?
> The Upper Cliff in Blount County, Alabama which Gastaldo referred to, the
> Pratt, Mary Lee, Blue Creek, Jefferson, Black Creek, Jagger, Nunnally
> Group, Nickle Plate, and a few others I can't remember right now (all in
> north Alabama) and the Kentucky No. 9, 10,
> 11 and 12 (I think we saw all of these) when I was with Steve Austin in
> Kentucky. From what we read, the Pittsburg would also fit.

Thanks for clarifying this. So you haven't actually seen the Pittsburgh?

> >Absence of rootlets in the underlying stratum
> >is good (though not conclusive) evidence for a coal being allochthonous
> >deposit. In my experience the nature of the underlying lithology is not
> >significant. I have seen transported plan material overlying both
> sandstone
> >and shale. I have also seen rootlets in sandstone as well in shale.
> However
> >you should remember blurring of boundaries in soils is largely due to
> >bioturbation by soil invertebrates. I would think these are rare in
> >waterlogged soil beneath peat. The environment is too hostile -water
> >saturated, low oxygen, and low pH.
> Root penetration and decay over thousands of years would blur the
> boundary, unless you are talking about a moss peat.

It depends of the rate of peat accretion.

> >I don't see why this is a problem. The rootlets you see are the last
> ones to
> >have formed. This is true whether you are looking at a modern soil, a
> >historically buried one, or an ancient ones in the geological record.
> When
> >you look at a soil in a the side of a ditch you only see the roots
> currently
> >present (and perhaps a few relicts). These will only be a small
> proportion
> >of all the roots that have infiltrated the soil. Also remember the
> surface of
> >peat accretes upwards. So there is not an infinite amounts of time for
> roots
> >to penetrate into the underlying substratum. Eventually the root zone
> will
> >be entirely within the peat.
> 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.

> >If only small rootlets are preserved, then the plants growing there had
> only
> >small roots.
> Jonathan, this is true only if we assume your autochthonous model is
> true. You have unconciously limited the range of possibilities by
> assuming one model. Close your eyes and repeat after me, "I am a YEC"
> ten times a day, and eventually you will see other possibilities. :-)

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.

I have done your thought experiment often, on many outcrops, without success.

> >If large roots are preserved, then plants with large roots are
> preserved.
> You need to get out of that box. Large roots are preserved, as are
> plants with large roots. But the large roots are not directly beneath
> the coal and the large stumps are not in the coal.

I don't see your point. What box are you talking about? Where are the large
roots if not directly beneath the coal?

> >We must go by what the evidence says. I can't see the problem
> >here.
> It's crystal clear to me. Keep thinking about it.

Point it out for the slow brains like myself.

> >>I have seen stumps and tree trunks
> >> above and below coal seams, but never in the coal, and I don't recall
> >> ever seeing a coal seam with a "pothole" interrupting the continuity
> of
> >> the seam. It looks like the stumps and trunks were floating in water
> and
> >> settled out.
> >
> > That is a good point, however, if the hole is filled by peat, it would
> be
> >hard to see. It would only clearly show up if the overlying sediment
> was
> >distinctive in character.
> Overlying light gray sandstone and gray shale are quite distinctive from
> black, vitrain coal. Vitrain coal with vertical joints is easy to follow
> because the light reflects off the joints which tend to be parallel. I
> have seen a coal seam which appeared almost totally reflective (white
> reflected light). If there were any infills from the overlying sediment,
> they should be obvious because of the reflective character of vitrain
> coal, which is common in Alabama.

Point taken.

> >There is layering and layering. Layering formed by physical sedimentary
> >processes looks very different to that formed by compression. The coal
> thin
> >sections I have seen are layered. The layers are defined by compressed
> plant
> >material, such as cuticle, not by transported sediments. What is the
> nature
> >of the laminae that you have seen, are they mainly the result of
> traction
> >currents
> What are "traction currents"? If these are impurities introduced by
> turbidity currents, then, yes. If these are stream channel cut-and-fill
> structures, I have heard of them in coal seams, but have never seen one.

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 have seen erosion by overlying sediments in the Eocene, Triassic, and
Permian. I gather they are also well documented in the literature of the

> >, or compression of compressive material?
> I have seen these laminae in pure vitrain. I suppose they form between
> sheets of vegetation.

Sounds good to me.

> >Have you seen them in thin section?
> No, but I had assumed coal would be too dense to see through. I thought
> it was studied in reflected light. I've done neither, but what is the
> best method?

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.

> > That sounds fair enough. But please define "intensely" and "deeply
> >rooted". The literature would suggest that such horizons are common.
> 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.

> >Partial preservation of lamination in the underlying material simply
> means
> >that there was insufficient root activity to destroy it.
> Exactly. So how long would it take a swamp to form 12 inches of coal.

How long is a piece of string? It depends on many variables. I understand
that Holocene peat accumulation rates vary by several orders of magnitude.

> >As I mentioned, the lack of a soil fauna in peat would minimise the
> mixing
> >between the peat and the underlying material. I have commonly seen
> sharp
> >contacts between modern peats and underlying substrates.
> Moss peats? Have you ever looked at the contact between organics and
> substrate in a swamp with tall trees and large, deep roots?

Unfortunately no, not with freshwater forested swamps. I have seen many
coastal swamps (mangroves) being dug up. The roots were shallow, because of
water logging and anaerobic conditions I understand that freshwater swamps
vegetation rarely has deep roots for the same reason.

> > So what is the problem? Four feet (1.2 m in real measurements)
> People who get up with their feet pointing in the direction their head
> should be are not qualified to determine what is real. :-)


> >suggests that
> >there were some deeply rooted plants in the overlying seam. I have no
> >problem with that, do you? Os this "deeply rooted" enough to meet your
> criteria?
> I'm still thinking about that. These roots were all "rootlets" and were
> all vertical as far as I could see. I'm not convinced that they were all
> connected to the coal. 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?

> >Not trying to steamroller anybody, just trying to help you see your
> >methodology and the task ahead of you.
> This is very helpful and I very much appreciate your time.
> Good night, and God bless,
> Bill

You too