>I said laterally extensive, not vertically extensive. The depth of
>root
>penetration is dependant on vegetation type and soil hydrology. I
>don't have
>the references here at home, but even in well drained soils the main
>root
>zone is generally within a 1 m or so of the surface. Individual
>roots do go
>deeper of course.
To add to what I said last night, I was back at the Village Creek site
today. The excavation crosses a monoclinal fold which is somewhat
faulted in the crest of the fold. The lowermost coal seam which I
described last night as resting directly on sandstone can, I think, be
projected across the open pit to the opposite highwall. At any rate,
whether the coal seam on the opposite wall is the same or not, today in
the opposite wall I looked at the rock (sandstone) beneath the coal and
was horrified :-) to see vertical rootlets hanging in the rock to a
depth of maybe four feet below the coal. The individual rootlets were
only about 6 inches long (or at least that's all I could see, they may
have curved back into or out of the rock face). This is evidence which
would, of course, be used to support your position that the coal is
autochthonous. I did not see the stigmarian axial roots from which the
rootlets radially extend, and I still have not seen stumps in the coal
and attached to root systems.
The lack of stumps still attached to root systems may be a critical
factor in differentiating autochthonous and allochthonous coals, rather
than automatically assuming that rootlets signify autochthonous coal.
Bill
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]