Thanks, good to see you again, Jonathan.
>I am glad that you have continued to reflect on these questions. It
>is great
>that you recognise the evidence for roots beneath at least some coal
>deposits.
>
>Your proposed allochthonous model is to my mind very unlikely. It
>might be
>just possible in rare instances, but to expect your model to explain
>all
>rootlet horizons beneath all coal horizons is taking special pleading
>to an
>extreme.
Picky, Picky! :-)
It fails completely to explain laterally extensive rootlet
>horizons
>beneath paleosols where there is no evidence what so ever for floating
>mats
>of vegetation settling on the dunes, or even for them being
>submerged.
>Occam's razor is an important component even in geology.
I would consider what you describe if I had ever seen such. Have you
seen or read of these "laterally extensive rootlet horizons beneath
paleosols" in the southeastern US? Every coal I can remember has either
had no roots or a shallow (~ 3 inch) root zone.
Today, I revisited the Village Creek excavation in Birmingham. The
excavation is now about 15 feet deeper than when I was last out there,
and another coal seam (the American seam) is exposed. The American seam
is sitting directly on light gray sandstone, and there is no evidence of
any carbonaceous material below the coal. You could lay a knife blade on
the contact and have coal above and sandstone below.
I also noticed several sections of a fossil tree trunk in a pile of
rubble. The base of the tree is as large as any I have seen, about 2
feet in diameter. You would think if such trees grew in coal swamps,
there would be some evidence of their stumps in the coal. Instead we see
unbroken beds of impurities stretching hundreds of feet horizontally in
coal seams. Where are the tree stumps if these trees once grew in coal
swamps?
In his paper, Bob Gastaldo showed a diagram of a Lepidodendron tree with
its Stigmaria axis system of roots. Gastaldo wrote: "Calculated depth
of stigmarian penetration is provided for two commonly encountered angles
of divergence [7 and 10 degrees from the horizontal] assuming no change
in axial direction." At a distance of ~ 12 meters from the base of the
tree, the deeper roots are ~ 4 meters below the surface. Why don't we
see these roots penetrating the "paleosols" below coal seams? Do you see
these roots below Australian coal? (Don't forget, you're looking at it
upside down!) :-)
Bill
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