Re: Fw: Re: Canadian Coal - depositional setting

From: Kevin Sharman <>
Date: Fri Feb 06 2004 - 00:38:54 EST

----- Original Message -----=20
From: "Bill Payne" <>
To: <>
Cc: <>
Sent: Wednesday, February 04, 2004 9:58 PM
Subject: Re: Fw: Re: Canadian Coal - depositional setting

Hi Bill,

A long post tonight...

> On Tue, 3 Feb 2004 19:28:17 -0600 writes:

> Surely if this was a swamp then some floods would be short-lived and
> vertical trees would be preserved in the partings.
Short lived floods wouldn't kill the trees, so they would keep growing =
and churn up the clastic material, resulting in no parting. In my post =
on petrology I make the point that for a parting to form, the swamp is =
first drowned by clean water, then the clastics come in.

> > No, the trees will not resume growing, because they died when the =
> was
> > flooded. Pioneering vegetation must take over again.
> Do you say this because grass and shrubs just take hold and grow more
> quickly than trees? I can see no reason why trees can't begin to grow =
> an unvegetated, moist surface. Other than the requirement that trees
> have to come later when the mat is thicker to explain the lack of tree
> roots in the substrate, what reasons can you offer for "pioneering"
> vegetation before trees when vegetating a parting?
I am in charge of reclamation at the closed mines where I work, so I =
know the basics of revegetation (but remember I'm a geologist). Whether =
it is the natural colonization process that we see on disturbed ground, =
or when we revegetate by planting, the pioneering vegetation is always =
shorter stature plants first (grasses and herbs today) followed by =
shrubs and trees. This is due to the low nutrient content of the bare =
mineral soil. Once the pioneering vegeation takes hold, leaf litter =
buildup and nutrient cycling begins. Then it will support larger =
vegetation. =20

I think the answer to the question of why there are not more roots below =
coal seams is that the roots we see preserved in the floor rock are =
those of pioneering plants which grew when the water table was =
relatively low. Once the water table rose, then peat forming plants =
kicked into high gear, and they didn't need to send their roots down =
deep into the floor.
> > > Parting destruction is a sure thing when you get roots. =20
> > Nope. Some tonstein layers in the South African Grootegeluk =
> coal measures contain 40% organic matter. It didn't > fall from =
> sky with the ash. Also see below.
> Is the 40% organic matter detrital or observed in roots? If it's in =
> roots, how can you be sure the roots are not also detrital?=20
The description of the one in South Africa doesn't give details. =
However, tonsteins form partings in some seams of the Gething Formation =
in northeast BC (Kilby, 1984) and the Mist Mountain Fm. in southeastern =
BC (Grieve, 1984). They range in thickness from 1 to 30 cm. Detailed =
examination of the tonsteins shows carbonaceous material. Grieve =
(1984): "The two bands in the Line Creek Extension locality.are =
separated by 1.2 cm of dark grey, very fine grained carbonaceous rock. =
The lower tonstein, which is 1.2 cm thick, is medium brown with black =
carbonaceous stringers.Rounded light grey blebs up to 2 mm in size are =
concentrated near the contacts of the band, and also occur in the =
enclosing 4 to 5 mm of dark grey carbonaceous rock."


"Both Ewin Pass samples are characterized by .gorciexite (a barium =
aluminum phosphate clay mineral, KS) with or without kaolinite, with =
thin stringers of organic material...Irregular subrounded ovoid bodies =
of microcrystalline kaolinite containing minor amounts of gorceixite, =
known as 'graupen', occur throughout..the lower brown band from the Line =
Creek Ridge samples was examined. Microcrystalline kaolinite forms the =
groundmass; it is cut by stringers of organic matter.graupen with highly =
irregular outlines are most abundant near the margins of the band..the =
organic stringers bend around the graupen."

"Contact with the enclosing dark rock is sharp; it is marked by the =
sudden occurrence of thick stringers of organic matter (liptinite?) =
...this corresponds with observations in hand specimen that graupen =
occur both within the brown band and in the enclosing rock."

So, he is saying that carbonaceous material occurs both within the =
tonstein and the enclosing fine grained rock. Graupen occur within the =
enclosing rock, so there is a gradational zone of graupen in the =
enclosing rock. Thick stringers of organic material appear at the =

>From the above description, I think the carbonaceous material represents =
flattened vegetation on the top and bottom of the tonstein and/or roots =
penetrating it. The contact is sharp, except for the graupen in the =
enclosing rock, so there is no destruction of the layer by roots, as you =
seem to think is certain. As to whether the roots are detrital, there =
is no sure way to tell from this description.=20
> > There is one of my pictures on Glenn's website showing a shale =
> with roots in it. The roots didn't even hardly disturb > =
> sedimentary layering, much less "bioturbate and destroy the =
> Occasional roots don't bother me; however, your model requires a
> continuous covering of shrubs over the entire parting area in order to
> produce a layer of vegetation which will support and contain the roots =
> all subsequent vegetation. This means every parting should be =
> rooted with a single stand of shrubs. Is that what you observe?=20

No. My explanation why there is not intense rooting below every parting =
is above. Your mental picture is that intense rooting is essential. =
This is an expectation that you have set up. Once you step away from =
this preconception, even temporarily, you will be free to consider other =
explanations. =20
> On Jan 5, 2004, you said: "I have shown you a parting with roots in =
> top of it, haven't I? I admit that this is probably the exception, =
> most partings don't have visible roots." Are you saying that partings
> that don't have visible roots have invisible roots?

No, generally you should be able to see roots or root traces if they are =
there, but in dark lithologies this may not be true.

> Maybe you can have it both ways (roots that don't bioturbate and roots
> that do bioturbate, roots that are visible and roots that are =
> depending upon changing conditions, but if so, could you please =
> the different in situ conditions that would result in bioturbation in
> some cases and not in others? And visible roots in some cases and
> invisible roots in others?

Pioneering vegetation doesn't have a high root density, so I have =
observed that it doesn't bioturbate the underlying sediment much if at =
all. As for Carmichael, he saw cases where in his judgement it was =
strongly bioturbated. Higher root density I guess. Once the peat swamp =
is fully established, root density is highest, and so is the capacity of =
these roots to bioturbate a clastic layer introduced by a flood (as long =
as the vegetation is still alive).
> Did Charmichael, Kalkreuth or others ever discuss this lack of roots =
> bioturbation in partings? If so, what did they say?

Not that I read.
> > Your choice of switching to a confrontational mode shows me that you
> are realizing that your argument is indefensible - you are > willing =
> reject well-reasoned interpretations that fit the evidence in favor of
> your vague arm-waving,=20
> I wholeheartedly agree that any confrontational mode is inappropriate,
> and I regret having slipped into it. I'll try to do better in the
> future.

Thanks. Me too.
> > in an effort to keep your faith intact.
> That's an interesting comment. If I may read between the lines, you =
> to be saying that anyone who seriously considers and accepts the
> empirical data relating to earth history will realize that the Bible =
> in error regarding Genesis 1 - 11, and if Genesis is in error then the
> stories about Jesus and much of the rest of the Bible are also in =
> (or mythological, as I once believed). Your comments?

I know very little about the Bible compared to the average ASA member. =
I will say that it's all a matter of interpretation. Biblical =
inerrantists see it one way, people like Glenn Morton say they have an =
interpretation that satisfies both geological evidence and the Bible, =
then there are agnostics, atheists, etc. Personally, I don't see the =
problem in considering parts of the Bible as historical, parts as =
allegorical, parts as having been changed along the way via retelling =
and translation. But I know others have huge problems with this. We =
are debating geology not theology, so I would like to leave this debate =
to others please.=20
> I tend to take a literal view of Genesis. The purpose of this =
endeavor I
> am embarked upon is to see how closely I can come to explaining =
> within the literal, YEC Biblical model. Supernova SN1987A (I think =
> discusses this on his website) gives me pause as far as a recent =
> of the universe, and Steven Smith posted a year or two ago a good =
> of the sequence of geologic events in Colorado (?) which I can't =
> within the YEC framework. Steven, if you have the location of that =
> handy you might want to let us know again where it is. In answer to a
> question you've posed a couple of times, yes, I would like to develop
> this model to incorporate one Flood that would be directly or =
> responsible for all of the coal seams worldwide.

Bill, the above makes our whole debate about the formation of coal =
pretty pointless. You have strong faith which includes taking the young =
earth/flood account from the Bible. That's fine, but with all due =
respect, bringing this to the table as the starting point, and trying to =
rationalize the data to fit this model, is not something that I would =
describe as science. You may not believe this when I say it, but I =
really don't care which model for the formation of coal is closest to =
the real explanation - I will side with the one that is best supported =
by the data. I think if you were to adopt this approach, and an old =
earth/non global flood explanation was best supported by the data, this =
would conflict with your faith. You would then be faced with choices - =
reject or ignore the old earth/global flood explanation to keep your =
faith intact (this is entirely your choice and I won't knock it), or =
modify/reject your faith.=20

I can't see that you can be objective with the beliefs you bring to the =
debate. An example of this stance is the Statement of Faith of Answers =
in Genesis. The last article reads "By definition, no apparent, =
perceived or claimed evidence in any field, including history and =
chronology, can be valid if it contradicts the Scriptural record. Of =
primary importance is the fact that evidence is always subject to =
interpretation by fallible people who do not possess all information." =
I think anyone adopting this has stated up front that they will not be =
objective. =20

As I have stated before, the degree to which one can be objective is the =
degree to which one can set aside one's preconceptions. I hope that I =
can set aside some or all of my preconceptions of an old earth to =
consider models of coal formation (maybe some would disagree with me on =
this), but if the belief in a literal reading of Genesis is a =
cornerstone of your faith which you cannot set aside, you cannot be =
objective. You will need to give more weight to data that you feel =
supports your position, and less weight to data that supports other =
positions; otherwise you will be forced to confront your faith. This is =
not objectivity. It's exactly what is happening in our debate, and is =
the reason why I said the debate is becoming pointless. You have asked =
many many questions to clarify my points, and I welcome them, time =
consuming as the research may be. But, you have come up with improbable =
explanations to support your model, i.e. dilution of seawater by =
torrential rainfall in inland seas to explain low sulphur coals, =
tonstein emplacement beneath floating mats, etc. Can anyone state that =
these explanations are impossible? No, but you have not made a case =
that they are reasonable and probable. You need to adopt improbable =
explanations because they fit your young earth paradigm. Let me ask you =
this - do you feel you are considering all the data objectively?
> Since you're read the archives you know a lot more about me than I =
> about you. Feel free to ignore this if you like, Kevin, but I would =
> to ask, what does your faith, if any, look like?

This is a debate about evidence explaining models of coal formation, and =
my personal beliefs are irrelevant to the topic in the narrow sense. =
However, since it may have bearing on the preconceptions I hold, I will =
share. I would describe myself as an agnostic theistic evolutionist. I =
look at it terms of probability. Is it probable there is a creator? =
Hard to say, but I won't rule it out. Is it probable that the evidence =
points to an old earth? Yes, based on what we have learned in a few =
hundred years of study of many independent lines of evidence. Are other =
explanations possible? Yes, but I prefer to go with the explanation =
that seems most probable. Does my personal stance make it impossible to =
be objective? I don't think so, but others might. =20
> =20
> > Instead of advancing coherent explanations of the depositional
> environment, you have ascribed interseam sediments and partings > =
> turbidites, well, maybe subaqeous deposits that may or may not be
> turbidites, well, I guess I can't explain tonsteins under a >
> floating mat... This is vague arm-waving.
> I don't think I understand the importance of the distinction between
> turbidites and subaqueous deposits.

Turbidites have a specific set of diagnostic characteristics: the Bouma =
sequence. They are from density flows of turbid fluid, diplaying graded =
fining upwards bedding. Sub-aqueous deposits, on the other hand, could =
include any sediments deposited underwater. This could include marine =
and non-marine environments, from pelagic oozes to alluvial =
fanglomerates, from carbonates to clastics. This is what I mean by =
vague. In order to explain the observed distribution of rock types =
associated with coal, you will have to be more specific about the =
mechanism of deposition of these rocks under a large (~20,000 km^2 for =
Gates coals) floating mat. Your assertion that they are subaqueous =
deposits will remain improbable unless and until you get specific. =
That's the way it works - present a well reasoned argument supported =
with observational data, and you have a good case. =20

>Also, I don't believe I said I
> couldn't explain tonsteins under a floating mat. I said: "I suppose =
> volcanic ash could fall on adjacent open water and then drift with
> currents under the floating mat." =20

You characterized this as "strained". I would characterize this as =
improbable. Carrying the ash 10's of kilometers laterally under a large =
floating mat and then depositing it in a thin layer, without mixing it =
with other sediment, all in the middle of a global flood, is highly =
improbable in my opinion. Unless you want to elaborate on the =

>I would add that ash falling on a
> floating mat might wash down through the mat with rainfall,=20

even more improbable, in my opinion

>and ash
> falling on adjacent land surfaces would wash into the water with
> rainfall. =20

mixing with other sediment would occur. There are many examples of =
"clean" (pure) tonsteins.

>Currents in the open water would disperse the suspended ash
> over wide areas beneath a floating mat.

Yes, they would disperse it all right - so it would no longer be a =
distinct layer. (Kilby, 1984): "any environment with more than a minimum =
energy level will obliterate ash falls. Thus, tonsteins and bentonites =
preferentially occur in low energy marine and coal swamp settings."=20
> =20
> > Your floating mat speculation is not the best fit for the observed
> data, and we're not even finished looking at all the data yet.
> We haven't begun to look at the Pennsylvanian data yet, which is where =
> believe the strength of my arugment lies. Right now we're engaged on
> your turf, and you have an excellent comprehension of your arguments.

Most of my objections to the floating mat model apply equally to =
non-Cretaceous coals, i.e. the sulphur problem, tonsteins, the =
association of coals with non-marine and shallow marine rocks only.
> > > Do you ever see coal seams of constant thickness draped over =
> of sand?
> > No.
> Does the banding in the draped coal follow the slope of the lenses or =
> it parallel to the general bedding plane (which originally would have
> been horizontal, or nearly so) and therefore at a low angle to the =
> of the sides of the sand lenses? I think you contend that banding
> results primarily from compaction, which should have been vertical due =
> sediment loading. Do you have any photos of draped coal you could
> forward?

The present slope of the draped coals and their surrounding rocks is 3 =
degrees steeper than the bedding in non-draped areas, according to =
Carmichael. I may scan some sections from Carmichael if I get a chance.
So Bill, is it worth continuing this debate?


Grieve, D. A. (1984): Tonsteins: Possible Stratigraphic Correlation =
Aids in East Kootenay Coalfields (82G/15, 82J/2), Ministry of Energy, =
Mines, and Petroleum Res., Geological Fieldwork 1983, Paper 1984-1, p. =


Kilby, W. E. (1984): Tonsteins and Bentonites in Northeast British =
Columbia (93O, P, I), Ministry of Energy, Mines, and Petroleum Res., =
Geological Fieldwork 1983, Paper 1984-1, p. 95-108.
Received on Fri Feb 6 19:13:38 2004

This archive was generated by hypermail 2.1.8 : Fri Feb 06 2004 - 19:13:38 EST