> Probably all Carboniferous coals are allochthonous, since the stigmarian axial
> root systems you require are curiously absent.
Twenty five minutes using the Georef CD-ROMs identified some 136 matches between the
terms coal, Carboniferous, Pennsylvanian, Mississippian, Stygmaria, paleosol, seat
earth, underclay, and paleosol for literature published in the years 1875-1998. There
is thus a considerable body of literature that presents evidence for in situ growth of
Carboniferous coals. Even if this interpretation proves wrong, these data must be
dealt with before alternative hypotheses are presented.