Re: Canadian Coal - depositional setting

From: Kevin Sharman <ksharman@pris.bc.ca>
Date: Wed Feb 25 2004 - 19:51:58 EST

Hi Bill,
> The same critique would apply
> to your explanation for "discrete beds of sporinite". Here is yet
> another explanation from you which requires a flooded condition ("a lake
> environment with an absence of clastic input"), followed by the
> reestablishment of a swamp without disturbing the thin, "discrete beds of
> sporinite".
Bill, Where is your explanation for beds of sporinite? You have not
answered my previous question about it in my post on Stokes Law. I don't
think you have a legitimate right to criticize an interpretation until you
come up with a better one yourself.

> > I have already shown you that roots can penetrate 10's of centimeters
>> into
> > the substrate without destroying the continuity of bedding (picture on
> >Glenn's website).
>
> Yes, but you haven't shown that these are in situ.
A series of vertical roots which look identical to modern roots, which
crosscut bedding and which are connected to the overlying coal is enough
proof for you to accept an in situ origin for roots in sandstone; why not
mudstone? Because you think you can explain the mudstones as turbidites,
you think you are justified in using a different mechanism (turbidite
emplacement vs. in situ growth) to explain the same data (vertical roots).
Trouble is, just saying that the mudstones are turbidites isn't enough. You
have to present evidence.
>
> You need to have a modern analog that shows pioneering vegetation was
> established on layered soil, and trees growing above the pioneering
> vegetation, with the layers of soil still intact, i.e., not bioturbated.
> If you can come up with such a modern analog, one which I can see in
> photographs or drive to and study for myself, then you will have undercut
> one of the primary supports of the flood model. I don't believe such a
> modern analog exists. You will also need to show that the weight of the
> trees doesn't compress the underlying organic mat, which would give the
> tree roots access to the mineral substrate.
Let's start with a quote that you had in a post (Dec 25): "Trees in the
mixed peat-swamp forest and pole forest...have spreading, buttressed, and
prop roots, which are generally confined to a root mat 50-80 cm thick at the
top of the peat and do not
penetrate to the deeper peat or mineral sediments below thick peat."
(from Neuzil, S.G., Supardi, Cecil, C.B., Kane, J.S., Soedjono, K., 1993.
Inorganic geochemistry of domed peat in Indonesia and its implication for
the origin of mineral matter in coal. Modern and Ancient Coal-Forming
Environments, GSA Special Paper 286, 25.)

Read this again, Bill: "roots.. do not penetrate to the deeper peat or
mineral sediments below thick peat". Sounds pretty clear to me.

> With all of the detailed literature you can access for coal petrography,
> can you show that the vegetation immediately above partings (inorganic as
> well as sporinite) is pioneering vegetation only, and doesn't contain any
> tree macerals?
No, because the coal immediately above a parting is from the main swamp
forming plants. The pioneering plants do not contribute much vegetation to
the coal.
>
> > You better think about how you can emplace vertical roots that we see
> >in
> > some partings with a turbidity current that flowed horizontally.
>
> It has since occurred to me
> that vertical detrital roots could result from floating plants with their
> roots still attached. In a swamp setting with saturated soil, if the
> swamp were overtopped with strong currents of water the soil would be
> eroded from around the plant roots as the plants were being uprooted. As
> the plants went into suspension, their roots would still be attached,
> hanging down in the water. Given the fluidity of the turbidity current I
> described in the acidified glass vial, it is quite possible that if the
> plants had settled to the bottom, still floating but with their roots
> touching the bottom, the sediment from a gentle turbidity current would
> settle around the plant roots without significant distortion.
Why do you think that all the plants would sink whole and be oriented in
growth position? All the floors of seams I've seen and read about contain
roots only, not roots, stems, bark, etc. If the source of your vegetation
is a ripped up mat of plant debris, it would be a mixture of all plant
parts, and as these waterlog they would sink, and be in all orientations,
but mostly horizontal. This is not what the data shows, is it? We see
vertical roots, not randomly oriented mixtures of all plant parts. Stokes
Law shows us that smaller bits would sink first, but you would have whole
plants sinking first. The turbidity currents you propose must be gentle.
What happens if they're not? You will get a churned up mass of mud and
plant parts, which will lithify to shale with randomly oriented coaly bits.
We don't see this in partings. It just doesn't add up, Bill.

Take a look at the picture on Glenn's website (the one with the hammer).
The mudstone shows laminations. How do these occur? Are you saying that
each lamination is a separate turbidite? Does the first turbidity deposit
hold the bottom end of the root in place vertically and the successive ones
gradually bury it, all while keeping the roots vertical?

> > No, I am talking about the photos on Glenn's website
> > http://home.entouch.net/dmd/cancoal.htm (both the ones in sandstone
> > and the photo with the hammer in it of roots in shale.
>
> OK, that's what I thought. You are assuming the fossil roots to be in
> situ, and using that assumption to prove your point. This is an example
> of what I have said - that it is often difficult to separate the data and
> assumptions. Your data is underlain by an assumption; if the assumption
> is incorrect then the data is invalid.
> I am willing to grant you that the apparent
> best explanation, given my current understanding, for vertical roots in
> sand is in situ.
> My best
> synthesis of these interpretations (putting aside my preconceptions) of
> in situ and insufficient roots is to say that the vertical roots
> represent an opportunistic growth, followed by flooding and deposition of
> organics from a floating mat.
Now we are getting somewhere. See what can happen if you put aside your
preconceptions? If you agree that roots in sand are from in situ growth,
why not roots in other lithologies? Because you can't explain the roots in
sand with a turbidity current, you are taking the wise step of calling them
in situ. You will agree that roots in mudstone that look the same as those
in sand can be in situ, right? If you want to stick with your turbidity
current explanation of roots in mud, you need to provide a lot more
supporting data.

You need a bout of opportunistic growth every time we see roots in sandstone
below a coal seam? That's a lot of episodes of dry land in the middle of
the Flood, over and over again, throughout the coal-bearing geologic record.
Your Flood scenario is not working.

> > You need a shoreline in this example. Are you proposing that your coal
> > forming floating mats needed a shoreline to bunch up against? This
> >would
> > require dry land in many places on earth from the Devonian to the
> >Recent.
> > Are you saying there was always dry land during the Flood?
>
> No, not during the early parts of the Flood.
Since the presence of shorelines (dry land) seems to be your mechanism for
bunching up plant material, explain whether or not dry land was present
during the deposition of all the Devonian to Recent coal measures.
>
> > Turbidity currents have a velocity. This would churn up your
> >waterlogged
> > floating plants which are resting on the bottom and make it very
> >unlikely
> > that they would all remain vertical.
>
> If the plants were suspended in turbid water and plants settled as the
> sediment did, then the roots would be buried in growth patterns.
So you are saying that all the roots would be buried in growth position, and
none of them would be horizontal or sub-horizontal. This doesn't work. A
current, which you need to deposit the mud, even a gentle current, would
push over the waterlogged roots. You have said they are suspended
vertically in the water at the bottom. This means their density is very
nearly the same as the water, and they would be extremely susceptible to
stirring up.
>
> > Show us modern or ancient turbidites where a single thin (~10 cm) layer
> >can
> > be traced for tens of kilometers. Back it up with references please.
> >This
> > is what you would need to explain a parting.
> Slide 48: ".the 'blue band'. parting of blue gray clay.generally ranges
> from 1 to 3 inches in thickness and lies a little below the middle of the
> coal. In most parts of Illinois there is an additional parting averaging
> inch thick 6 to 10 inches below the blue band, and at many places a
> minute dark shale or clay parting averaging 1/8 inch is 1-1/2 to 2 feet
> below the top of the coal.
> Here are three very thin partings covering roughly a quarter-million
> square miles. Your explanation within the swamp model?
You have done exactly what you objected to above: You are assuming the
partings to be turbidites, and using that assumption to prove your point.
You have not shown that these are turbidites at all. The literature
suggests quite a different origin:

Rice: "The No. 11 coal bed at the top of the formation contains a
distinctive clay shale parting and can be traced throughout the Eastern
Interior basin. The parting, 2 to 4 in thick, is commonly light bluish gray
and is referred to as the "blue band." It has a pelletal or grainy structure
similar to some flint clays that are alteration products of volcanic ash
falls."

This is evidence that the blue band may be volcanic (i.e. a tonstein), but
you use it as an example of a turbidite. As for the other partings
described, I would not be surprised if they were found to be tonsteins too.

I will repeat my statement: "Show us modern or ancient turbidites where a
single thin (~10 cm) layer can be traced for tens of kilometers." This
should be supported by a consensus that your example is a turbidite,
supported by references, not just your own declaration that it's one.

Tonsteins are well known from Appalachian coals. These are your "thin,
widespread partings" that do not need a turbidite explanation.

Rice: "The Fire Clay coal bed and its correlatives have long been
recognized as a regional marker owing to a distinctive flint-clay parting
that is generally present. The parting is interpreted as a volcanic ash fall
(Seiders, 1965; Bohor and Triplehorn, 1981), which, though not continuous,
has been traced widely in the central Appalachian basin in West Virginia,
Virginia, and Tennessee as well as in eastern Kentucky. The flint-clay
parting ranges from a fraction of an inch to as much as 14 in thick and is
generally dark brown, microcrystalline, and hard and fractures conchoidally.
Similar partings are associated with at least five other coal beds in the
Middle Pennsylvanian strata, and where the principal parting is missing or
poorly exposed, these other coal beds have been locally misidentified as the
Fire Clay coal bed. Other coal beds that contain flint clay partings are a
bed in the Amburgy coal zone, the Little Fire Clay coal bed, and beds in the
Hazard, Peach Orchard, and Skyline coal zones."
>
> So why don't we see roots penetrating the tonsteins and partings?
I quoted Grieve (1984) describing organic stringers in the tonsteins he
studied. This is evidence for roots; not conclusive, but evidence
nonetheless.

> (Creech,
> Michael, 2002. Tuffaceous deposition in the Newcastle Coal Measures:
> challenging existing concepts of peat formation in the Sydney Basin, New
> South Wales, Australia. International Journal of Coal Geology 5, 185-214)
From the abstract of the paper referenced above: "It is proposed that the
peat surface was predominantly below the water table, and the term "lowered
mire" is proposed to describe this environment. A subaqueous peat surface
would protect thin volcanic ash deposits from subsequent redistribution by
rainfall and surface runoff, and is consistent with a lack of tree
preservation within the intraseam tonsteins. It is envisaged that trees were
generally restricted to the peat margins, and to specific horizons where the
peat surface was exposed by a fall in the water table."

Since you have the entire paper, please quote those parts which present the
author's comments that explain the data with an in situ model, then try to
explain why those conclusions are invalid. I can't help thinking you left
those parts out on purpose.
> I've read that clay compacts about 2x. Why would tonsteins compact 6x?
I have not read Lyons (1992) but I would think that the bulk density of the
fresh ash layer is low, and it compacts a lot to give us the hard layer we
see today.
> Ash falls on open water, goes into suspension and disperses over a wide
> area, including the areas beneath floating mats, as it settles to the
> bottom.
>
> > I have already pointed out that volcanic ash would be mixed and
> obliterated
> > if picked up by a turbidity current. So, yet again, you still have not
> > explained the mechanism.
>
> See above.
You still haven't shown how an ash fall can escape obliteration by being
carried under a mat by currents. You say that it does, without giving
evidence to support your statement. As I explained above, the ash is light
and is also very fine, and is extremely susceptible to mixing.

>
> > You would rather have us accept an argument based on completely unknown
> > parameters? I asked you to assign some numbers to the dilution of
> >seawater;
> > instead you dismiss my sulphur argument (supported with data) in favor
> >of an
> > unexplained phenomenon. I can't call that science.
>
> If the evidence points toward an event with unknown parameters, are you
> going to reject the event? Do you accept the "Big Bang" origin of the
> universe? What parameters do you propose for the origin of the universe?
There is no need to invoke unknown parameters if the evidence can reasonably
be explained by known ones, as I have done. You are rejecting my
explanation in favor of an event with unknown parameters. You have not
justified this, therefore your rejection of it is invalid.

> So, Kevin, I've been an agnostic for 10+ years, a Christian not
> interested in origins science for about 15 years, and a Christian
> interested in science from a creationist perspective for about 14 years.
> My primary motivation is not defending the Bible so I can keep my faith;
> it is removing barriers to faith so folks like you can openly and
> honestly consider the life and claims of Jesus. Do you believe, as
> Julian the Apostate did, that Jesus performed the miracles ascribed to
> him in the gospels (Matthew, Mark, Luke and John)?
Thanks for the life story. Mine will not be forthcoming. I have no idea
whether Jesus performed miracles, and I would prefer to stick with the topic
at hand.

Kevin

Rice, Charles. USGS Professional Paper 1151-H The Geology of Kentucky -
Pennsylvanian System http://pubs.usgs.gov/prof/p1151h/penn.html
Received on Wed, 25 Feb 2004 17:51:58 -0700

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