Bill Payne wrote:
> On Tue, 30 Mar 1999 20:33:56 +1000 Jonathan Clarke
> <jdac@alphalink.com.au> writes:
>
> >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?
>
> Yes, but one thing leads to another. If the transported model eventually
> wins out over the swamp model for coal, this will beg for the
> re-examination of other strata. If it turns out that the data indicate
> that coals from the Carboniferous around the world are likely
> transported, then other associated strata will have to be reinterpreted
> in light of transported coal.
I don't see that as a necessary outcome.
> I tend to be very analytical, and I am trying to proceed carefully,
> making sure each step is on solid ground. I don't want to get into arm
> waving and over extend my observations. These exchanges with you, Keith,
> and others are valuable for exposing weaknesses and errors in my
> thinking. Thank you for engaging me.
>
> >If correct, this could be an important observation. You need to
> document the
> >proportion of stumps which have this feature [no roots] to see whether
> it is an isolated
> >example or a general characteristic.
>
> They _all_ have this feature; I have never seen a stump with attached
> roots. If I did, that circumstance could still be interpreted as
> allochthonous, since moving water could erode the soil from around the
> roots before the stump was sheared off, and then the stump with roots
> attached could float to a new location, settle to the bottom and be
> buried. There is an article in the current _Creation Ex Nihilo_ magazine
> which describes this set of circumstances for the trees at Specimen
> Ridge.
>
> >>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?
>
> The only mineral matter (impurities) I can see in coal are partings. I
> think the dispersed mineral matter would be seen as a higher ash content
> (or perhaps would be visible in thin-section).
>
> >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
> these?
>
> Sorry, my 1966 AGI dictionary doesn't have "Bouma sequences" (it did have
> "tractive currents"). Can you define?
I am surprised, I thought they had been defined by them. OK. A Bouma
sequence is that classic upward fining sequence formed by turbidites. They
are named after Bouma, one of the initial turbidite workers. The Bouma
sequence consists from bottom to top of the A, B, C, D, and E divisions.
A = basal upward fining sand over an erosional bed.
B = massive sand
C = rippled sand
D = silt to mud
E = hemipelagic mud (essentially background sedimentation).
The sequence is rarely complete, proximal and coarse grained turbidites are
typically A-C (+ E) and distal or fine-grained turbidites D-E. The E
division mat be eroded of by erosion flow prior to deposition of the next
sequence.
>
> >> 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
> fast
> >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.
>
> I had in mind the substratum being transported in as turbid water or
> turbidity currents, and settling in around the exposed roots.
>
> >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.
>
> That is my hunch, my working model, which would of course have to be
> eventually supported by additional studies, as you have pointed out.
>
> >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.
>
> Here are a couple (from Steve Austin's CatastroRef) you might want to
> consider:
>
> ">>590 Bennett, M. R., Doyle, P., and Mather, A. E., 1996, Dropstones:
> their origin and significance: Palaeogeography, Palaeoclimatology,
> Palaeoecology, vol. 121, pp. 331-339.
>
> A dropstone is an "exotic" or larger clast occurring in a fine grained
> matrix or claystone, and is out of place with the surrounding sediment
> that contains it. A contradiction exists. For transportation to occur,
> larger clasts require a higher energy regime compared with the lower
> energy, fine grained sediments. The question is, how does an outsized
> clast get deposited in a low energy environment? Several mechanisms for
> the emplacement of these stones are suggested including: biological
> rafting, iceberg rafting, floatation, gravitational and projectile.
> Large clasts caught up in the roots of floating stumps are observed in
> both modern and ancient sediments and may explain why we find cobbles
> and boulders in coal beds."
I have seen quite a few dropstones of all sorts, including examples I have
interpreted as glacial, volcanic projective, impact projectile, and
vegetational rafting.
> SCHULTZ, Leonard G. 1958. Petrology of Underclays. Bulletin of the
> Geological Society of America, Volume 69: pp. 363-393
>
> Schultz analyzed 400 samples from ten underclay zones located in the
> Appalachian, Mid-Continent and parts of the Illinois basins by X-ray
> diffraction, and concluded that the mineralogy of the underclays did not
> reflect degradation by weathering, as would be expected if the underclay
> had been a topsoil. Field observations by Schultz showed "…that
> underclays were formed before deposition of coal-forming material began
> and therefore cannot be the residual soils on which the coal-forming
> flora grew." Schultz therefore concluded that the underclays were not
> residual soils which weathered in situ, but rather the result of
> transportation and flocculation of clay.
Schutz's study is largely discredited these days and has been superseded by
many studies which do show weathering in paleosols. Not only that, they show
many different weathering styles which reflect modern variations in
weathering and which are consonant with other palaeoclimatic indicators in
the sediments. A good place to start is Greg Retallack's book "Paleosols" (I
think).
> >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?
>
> No, not on the basis of size of modern peat deposits. I would have to
> see the same features of modern peats in ancient coals, which I do not
> believe I have yet.
>
> >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?
>
> ALL of the ancient coals would be ideally shown to be transported. If
> they could then be shown to have all been transported in the same time
> period, then that would point to a worldwide flood event.
>
> >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?
>
> I guess it would wash my support out. If I continued in my belief in a
> global flood, it would be by faith only - who knows, I might even become
> an OEC!
>
> I found my Gastaldo paper at the office today. I will try to get it in
> the mail tomorrow.
>
> Bill
God Bless
Jonathan