R E M A R K A B L E C O A L M I N E .
the day vve were there, and I could only
proceed a short distance into it. The position
of the coal being nearly vertical, it
can scarcely be said to have a ro o f; but on
the eastern side, which we will call the top,
there is a thickish bed of imperfect coal,
or rather bituminous schist, over the true
coal, which yields a flame when exposed to
heat, though it will not burn by itself
There is a bed of tender sandstone (molasse),
and a bed of light grey earthy limestone
over the coal; and also a bed of dark
earthy limestone, containing bivalve and
univalve shells, which I believe forms the
roof to the imperfect coal before mentioned.
The univalve shells were shattered
and compressed. I was not so fortunate as
to procure specimens, but a friend of mine
obtained some, which resembled cerithia,
they were imperfect. The bivalves bear a
resembiance to cytherea, but neither M.
Brogniart at Paris, nor Mr. Webster in
London, to whom I showed them, were
able to decide to what genus the}^ belonged.
Between the coal there are thin seams of
black calcareous schist, intermixed with
very thin laminae of shining coal. The
R E M A R K A B L E C O A L M I N E . 189
coal is situated nearer to the limestone
which forms the eastern side of the mountain,
than to that on the western side: from
the latter it is separated by numerous beds
of sandstone, which, from the colour of
the water that issues from them, appear to
contain much iron. The thickness of the
sandstone-strata containing coal may be
150 yards. I paced over it, and saw its
junction both with the upper and lower
limestone, but I omitted to note down the
distance. The upper limestone is highly
indurated, and nearly white; it is translucent
at the edges, and possesses the mineralogical
character of a primitive limestone ;
but it covers strata containing shells that
in England are peculiar to the upper calcareous
formations : and in other situations
in Savoy, I have seen similar limestone alternating
with strata analogous to our green
sand, and containing similar fossils. Some
of the beds of this limestone were striped
with red veins, the colour of which proceeded
from an infiltration of water, impregnated
with iron. The lower limestone
differs in colour from the upper, being grey.
The direction of the strata is S.S.E. and
N.N.W., as I ascertained with a compass;
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