said, indicate the cause by which the strata
have been raised ; for the connection which
earthquakes have with subterranean heat
can scarcely be doubted, though we are
profoundly ignorant respecting the mode
of its operation. It is worthy of remark,
that in the vicinity of these vertical beds
of puddingstone, and sandstone, fragments
have been found of a rock bearing a striking
resemblance to, if not perfectly identical
with rocks acknowledged to be volcanic.
These fragments were discovered
by Saussure above the Valorsine ; the stone
is a whitish grey, earthy, felspar porphyry,
containing a few crystals of felspar, and
small brilliant specks of mica, exactly resembling,
in all its characters, the rock
now called trachyte, of which several of the
volcanic mountains in Auvergne are principally
composed. I do not think, however,
that any important inference can be
drawn from the mere resemblance between
these rocks, taken as an insulated fact, such
resemblancesbeingin themselves insufficient
to serve as geological characters, but when
associated with several other facts, all tending
to confirm the same thing, they are not
to be entirely disregarded. One important
fact may be deduced from these elevated
beds of puddingstone, sandstone, and other
strata, ranging conformably with beds of granite
and gneiss; namely, that the granite did
not acquire its highly-inclined or vertical
position, till after the formation o f secondary
strata, which are comparatively modern,
as I believe I shall be able to shew those in
the Valorsine and in the valley of Chamouny
to be. This opinion is, I know, at
variance with that of many geologists.
Daubuisson, as if he had been present at the
time, states, “ that the beds of granite in
the Alps were raised into their present vertical,
or highly-inclined position, soon after
their formation, ’ an opinion opposed by the
position of the secondary strata, both here
and in every part of the Alps that I have
examined, unless we admit the granite to
be also of recent formation. In Engo land,"
the lower secondary strata appear to have
been elevated by the same cause that raised
the rocks on which they repose; but this
elevation took place before the deposition
of the upper strata consisting of magnesian
limestone, lias, oolite, and chalk, and the
intervening sandstones ; for all these strata
lie nearly flat over the edges of the inclined
VOL. II.