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308 COAL,
that the vegetable impressions accompanying
the Alpine anthracite, are more ancient
than those found in the regular coal-strata
in England. The occurrence of bituminous
coal, and anthracite, in the same beds
in England, proves that the absence of
bitumen can determine nothing respecting
the relative antiquity of different kinds of
coal. M. Von. Buch has observed even
granite covering coal in Norway; therefore,
instead of asserting that the anthracite
of Savoy is very ancient, because it
is associated with mica slate, may we not
with equal probability assert, that the mica-
slate is comparatively recent, because it
covers coal and schist, in which are vegetable
impressions ?
There is a striking similarity between the
structure of the anthracite from the mica-
slate, and that of the carbonaceous matter
in the gypsum, before described in the
lower part of the valley. This would tend
to confirm the opinion, that they were
both allied, as members of a continued
formation.
M. Brogniart has truly observed that
the ancient primitive granite, of which
former geologists speak, appears to exist
G R A N I T E . 309
only in countries that have not yeV tiieen
examined, which is nearly the same as
declaring its existence to be imaginary ;
indeed, if the granite of the Alps, be not
primitive, it is in vain to seek for a primitive
formation of this rock, in any part of
the world.
Whatever may be the period at which
the granite of the Alps was formed, it may'
be proved by decisive facts, that it did not
acquire its present position, till after the
formation of the secondary calcareous
strata, by which it is covered, These facts
will be referred to in some of the succeeding
chapters. Mon. Daubuison has asserted,
that the granite of the Alps acquired its present
position soon after the date of its formation.
This is merely an assertion ; were
it proved, we could have no doubt that the
granite was of posterior date to the limestone,
as I shall endeavour to show hereafter.
In the present state of our knowledge,
I am inclined to think that system of
geology is most consistent with existing
appearances, which maintains that granite
has been formed from the fusion of preexisting
rocks, and was thrown up and
crystallized subsequent to the deposition
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