> Two weeks ago in response to my assertion that there was no case of a
> polystrate tree beginning in a coal seam, going through a coal seam and
> ending in a coal seam, I had asked,
>
> >Can you provide a reference for the polystrate tree through several strata of
> > coal?
You may remember that I responded with a question about whether
anyone had seen a fossil tree passing through any coal seam. The
quotes Glenn provides illustrate the point I was making:
> "Since this particular tree at Blackrod was described more than fifty trees
> fossilized in position of growth have been observed in Lancashire, mmostly
> on opencast coal workings. These trees are found at various horizons
> between coal seams, and they occur, also in partings within coal seams.
> Where trees occur in the roof beds of a coal seam the root system is
> developed in the beds above the top of the coal; in no case has a tree been
> observed to pass from the roof into the coal itself.
This is VERY important observation. The old idea of trees being
fossilised in growth position surrounded by a peat soil do not match
up to observation. The root systems of these trees are not in seat
earths.
Glenn writes:
> The interesting thing is that the fossil trees are not found in the slowly
> deposited, fine grained, organic rocks . The trees are found in
> coarse-grained rapidly deposited sediments,
You are right. This also is VERY interesting. The sandstones
enclosing these trees is high energy.
Fred Broadhurst summarises the observational evidence:
> "The significance of the upright trees in Lancashire, so far as this study
> is concerened, is that they were all found enclosed by fine sandstones,
> siltstones, and coarse-grained mudstones but not by the fine-grained
> sediments, including those containing shells.
Glenn, these field evidences, in my opinion, are consistent with the
idea that these trees are allochthonous. They are consistent with
the idea that (local) catastrophism is involved. Those who want to
defend the idea that these tree were buried in situ have a bit more
work to do to show that their models match up to the test of
observational data.
It occurs to me that most of my experience is with Carboniferous
strata, and Fred Broadhurst was writing about Carboniferous strata.
Several people have commented to me that there are significant
differences between these rocks and the coals of the Permian, Mesozoic
and Tertiary. It is possible that there are polystrate trees passing
through coal seam(s) - but I will predict that if they do exist, they
will be found in the Permian, Mesozoic or Tertiary strata.
Best wishes,