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426 BEDS OF GRANITE AN D LIMESTONE,
Such facts indicate that the granitic and calcareous
beds were elevated together by the
same cause, and at the same time ; this is
more fully confirmed by the similar direction
and position of the beds of granite
and the secondary strata in Savoy. See
p. 12 to 18 in this volume.
The cause by which both the southern
and northern range of the Alps were
elevated, appears to have acted most intensely,
and probably at the same time,
along two nearly parallel lines, distant from
each other about twenty-five miles, forming
the two great Alpine chains on each side of
the upper valley of the Rhone, described in
Chap. VI. of the present volume. The
cause or moving power by which these
ranges were elevated has also acted, but with
less force, along a number o f nearly parallel
lines, forming the lower ranges which border
the northern side of the Alps.
Wherever the surface was much broken
and elevated in one part, it may be supposed
that other parts would sink down,
and in certain intermediate spaces, the
position of the strata would remain unchanged,
and be nearly horizontal ; and
these changes from a vertical to an horiTHFIR
ELEVATION CONTEMPORANEOUS. 427
zontal position may often be observed in
the Alps, both in the beds of granite and
gneiss, as well as in the calcareous strata,
but far more frequently in the latter.
The general direction of the beds, both
in the northern and southern range of
Alps, is principally from north-east to
south-west, or from north-north-east to
south-south-west. In th e central southern
range, the granitic rocks which form the
highest summits, are uncovered by any
other formations; but in the northern
range (at least that part of it which divides
the canton of Berne from the Valíais), the
granitic rocks are most frequently covered
by calcareous strata, and granite and rocks
called primitive are seldom seen, except
in the valleys and gorges by which this
chain is intersected. One traveller boasts of
having reached the summit of the Jungfrau,
and discovered upon it hornblende
with mica and clay slate ; but I found that
the accuracy of this statement was much
doubted at Berne. I was several days
at the foot of the Jungfrau, and I frequently
examined its summit with a telescope, on
the side where the escarpement is almost
perpendicular and uncovered with snow, and
it appeared formed of strata that were nearly
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