Re: Roots in coal?

  ----- Original Message -----
  From: bpayne15@juno.com
  To: ksharman@pris.bc.ca
  Cc: asa@calvin.edu
  Sent: Thursday, December 25, 2003 3:37 PM
  Subject: Re: Roots in coal?

  Hi Bill,
  This one is shortened to make it onto the list, but my comments are the same as the one you got.

  On Fri, 19 Dec 2003 23:36:58 -0700 "Kevin and Birgit Sharman" <ksharman@pris.bc.ca> writes:

> "If a vitrinite layer shows no structure

  But the vitrinites do show banded structure, which is what would be expected if the macerals settled from a floating mat.

  Stach is talking about microstructure here. What is your explanation of banded structure in these Cretaceous coals? What makes up the bands? Remember, these are not Lycopod dominated coals with lots of bark.

  Stach has found another explanation, but I'm not convinced that a mass of intertwined roots can be "metamorphosed" into horizontal bands. "Masking" the cell structure is quite different from _metamorphosing_ the original fabric of the peat into a fundamentally different material structure.

   I repeat my contention that gelification destroys and masks the original plant structure. The banding in coals is from the original vegetation types and the coalification history of the peat. The same parent vegetation can make layers of different macerals depending on its history of transformation into coal.
  Here are quotes from the International Commission of Coal and Organic Petrology (ICCP) New Vitrinite Classification (ICCP System 1994) http://www.iccop.org/ , explaining the derivation of the different marcerals in the vitrinite group.

  Vitrinite group as a whole: "derived from parenchymatous and woody tissues of roots, stems, barks and leaves composed of cellulose and lignin. Depending on the process of decomposition, the degree of gelification and rank, cell structures are preserved and visible to varying extents."

  Collotelinite: "derived from the parenchymatous and woody tissues of roots, stems, and leaves composed of cellulose and lignin and originating from herbaceous and woody plants. By geochemical gelification (vitrinization) the primary structures disappear."

  Detrovitrinite: "derived through the strong decay of parenchymatous and woody tissues of roots, stems, and leaves originating from herbaceous and woody plants, originally composed of cellulose and lignin. By chemical decay and/or mechanical attrition the former structures have been broken down."

  Collodetrinite: "the original plant tissues are destroyed by the strong decomposition at the beginning of the peat stage. The small particles are cemented by humic colloids within the peat and subsequently homogenized by geochemical gelification (vitrification)."

  This is an explanation of what happens to veg material as it coalifies, and where the whole logs, roots, stumps etc. went. If there weren't processes like this going on, we would see all the roots that were in the original peat.

> The inertinite maceral group preserves cell structure more than the
> vitrinite group.

  And why would this be so?

  The formation of inertinite macerals is by oxidation of the peat, which "pre-coalifies" the material, making it resistant to further coalification. More on inertinite in a future post.

> As is so often in geology, things are not clearcut. If there were
> abundant roots, it would support my view. If there were no roots
> found, it would support your view. The fact there are some roots puts us
> right in the middle, doesn't it?

  The quote from me above is in reference to roots within the seams.

  OTOH, for you to support "some" roots beneath a swamp peat, you need to find a modern analog. The peat swamps I have read about and seen photos of all show _intensely-rooted_ mats, which is not what we see in the root zones of your photos. "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.) You need to show a root mat, Kevin, not individual roots and _occasional_ radiating roots. What you have shown to date supports my model, not yours.

   I have shown you pictures of roots below the seams, about which you stated (Dec.18): "I agree that the radiating roots in your last photos
  are, as far as I can tell, "identical to ones that grow in place today."" Your objection to these demonstrating insitu growth is that there are not enough of them. Then you quote a paper supporting my position: "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." (my emphasis).
  I have also shown you references to roots within these coal seams. Here's one more for good measure: From Lamberson et al (1996): " As observed during the standard point count analyses (no quantitative analysis was done), fusinite and semifusinite represent discrete plant organs, principally stem and root wood, leaves, and bark of gymnosperms as well as the leaves and rhizomes of ferns."

   I have explained petrographically how the characteristics of the original vegetation are obscured and destroyed during coalification.

  It appears that you will not accept this explanation. You are objecting to it because it doesn't satisfy the criteria you have laid out for you to accept this as insitu coal. I submit that these seams are insitu based on what we've seen so far. You are welcome to reach your own conclusions about this. Readers of this (if any) are also free to make their own conclusions. There is more evidence which we will discuss in due course that points to an insitu origin for these coals.

    In other words, why do Carboniferous coals with their
> characteristic vegetation accumulate in the areas they do, and Jurassic and
> Cretaceous coals with a different unique vegetation accumulate in other
> areas, when you are proposing that they were all floating around
> together?

  I didn't say they were all floating around together.

  They floated on the same ocean, correct?

  They were segregated in life, and remained segregated after being lifted by the rising flood waters. We're talking about massive mats of vegetation, not loose debris.

  If you are saying that they remained segregated, you need to propose how this would happen, with currents, longshore drift, etc. acting on the mats.

> While we're at it, why are coals associated with characteristic
> rocks, principally non-marine sediments, and not deep water ocean
> sediments, pyroclastic volcanics, evaporites, chalks, etc? In a flood
> scenario, these rocks were all being deposited in that year, and in your model,
> shedding mats should have dropped veg material on them and made coal. We
> don't find coal in these rock types, do we? To me, this is a falsification of
> the Biblical flood floating mat model. Your thoughts on this crucial
> point?

  I don't see the flood as a big mixer, but rather a big lifter. You, Glenn and so many others that try to refute the flood model wave your arms and say everything should have been mixed together if there were a flood. You're not looking at empirical data when you say that, you are using your imagination to prove your point - not exactly the best way to do science.

  Bill, you have not answered my question. Let me restate it: Suppose you lift a mat up with a flood. You can keep it stationary or float it around; it doesn't matter. Directly below the Gates coals there are ~8000 meters of Phanerozoic sedimentary rocks. These are a variety of types including deep water marine mudstones, shelf carbonates, evaporites, turbidites, etc. None of the above rocks have coal in them. Why not? How do you explain the fact that only sediments characteristic of shallow marine and non-marine environments have coal in them, if all of the above rocks were being deposited underneath a floating mat? Until you can come up with a plausible explanation for this, backed up with evidence, your floating mat model will remain in the realm of speculation.

   "burial with overlying sediments to the depths needed to coalify the peat" is an assumption about how coalification proceeds, and it's my job to challenge all those assumptions.

  If you want to challenge the "assumption" that burial is responsible for coalification, you need to provide your own detailed model. The relationship between rank (degree of coalification) and depth of burial has been established in many coal basins. "Near surface coals in the Alberta plains increase in rank toward the west-southwest (that is, towards the foothills/ mountains region). A new model to explain this coal rank distribution is proposed. This model relates a coal seam's rank to its maximum (paleo)depth of burial....Progressively greater amounts of overburden existed in a direction toward the mountains at the time of coalification. Erosion since middle Tertiary time has removed between 900 and 1900 m (3000 and 6200 ft) of sediment; the greatest amount of removal is in the west southwest area, where coals of higher ranks are exposed." Nurkowski, J.R. (1985) Coal Quality and Rank Variation in Upper Cretaceous and Tertiary Sediments, Alberta Plains Region. Alberta Geological Survey, Earth Science Report 85-01.

   "Waterworn pebbles of banded coal often occur in the base of the overlying sandstone and, according to a few specimens which were examined for microfossil content, they appear to have been derived from the Pittsburgh coal itself. It is very difficult to explain how such coal pebbles could have been loosened from a coal seam, then so recently deposited, and become waterworn and then have been redeposited in the first sandstone to be laid down such a short time later. By the time of reworking, the peat deposit must have been advanced in rank at least to the stage of lignite for the pebbles are normal banded, have well developed cleat and usually retained their basic shape even though they very often lie at some angle to the bedding plane of the underlying coal or shale."

  So there is at least some data from coal pebbles that burial may not be required to initiate the coalification process.

  Early coalification can be caused by fusinitization, where the peat is transformed either by charring, oxidation, mouldering, and fungal attack. Fusinite is relatively resistant to chemical and mechanical breakdown and can form particles which can be transported by water. This has been reported in the literature; even Steve Austin's abstract mentions fusain clast conglomerate.

  Kevin
Received on Tue Dec 30 22:56:44 2003