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miles in length and two in breadth. By
whatever cause they have been raised, it
must be obvious that at the period of
their elevation, the present mountain-valley
was not excavated. We have not here to
enquire whether the waters that scooped
out these valleys, were those of a mighty
deluge that swept almost instantaneously
over the globe with an immense force, or
whether the valleys were gradually excavated
by rivers running along them, though
the latter hypothesis seems scarcely adequate
to the effect, as the heads of the valleys
are low, compared with the mountains
by which they are bounded. But whether
the waters were diluvial or fluviatile, we
cannot doubt that it was by their agency
that the beds of soft sandstone have been
washed away.
I am not aware that any geologist has
hitherto adverted to the alternation of hard
and soft strata, as offering an explanation
of the formation of these mountain-valleys.
To me it appears satisfactory. I am far,
however, from believing, that all valleys
were formed by the excavation of soft
strata ; many of the valleys in this part of
the Alps appear most evidently to have
been formed by a violent derangement of
the strata, which has elevated them in one
part and depressed them in another ; but I
must refer thé reader to another part of this
work, for the further consideration of this
subject.
The formation of many of the cols or
depressions in the ranges of the higher
Alps admit of a similar explanation ; but
of these I shall elsewhere speak.
What has been said of the structure of
the mountains, in this part of Savoy, may
serve to explain the cause of those great
eboulements that sometimes occur. I shall,
therefore, proceed to describe the present
appearance of Mont Grenier, about five
miles south of Chamberry, which we visited
the day after our journey to les
Echelles. A part of this mountain fell
down in the year 1248, and entirely buried
five parishes, and the town and church of
St. André. The ruins spread over an extent
of about nine square miles, and are
called les Abymes de Myans. After a lapse
of so many centuries, they still present a
singular scene of desolation. The catastrophe
must have been most awful when
seen from the vicinity ; for Mont Grenier
is almost isolated, advancing into a broad
o 2