C A R B O N A C EO U S S T R A T U M
cut a number of deep ravines in it about
half a mile or more distant from eacli other.
There is a mule road at a considerable
height on the side o fth e mountain, which
is obliged to wind along each of these
ravines, and thus affords aii opportunity of
observing sections of the strata, in different
parts. A very large raidne almost immediately
above the first bridge, presents the
following section of the strata : see annexed
cut. —
The strata rise to the north-west, at an
angle of about 40°; the lowest beds in this
ravine are, —
1. Limestone, which, from an intermixture
with talc, is nearly schistose.
2. Talcous schist, with beds of decomposing
talc ; light green, and very saponaceous.
3. Limestone, coated with talc, and containing
irregular laminas of quartz.
4. Soft earthy gyps.
IN GY VSUM.
5. Red anhydrous gyps ; sp. gr. 2.83.
6. Grey do. ; sp. gr. 2.80.
7. A very thick bed of white earthy
gyps, like No. 4., in the middle of which
is a black carbonaceous stratum {a) about
eiii'ht inches thick.
These beds are described upwards, from
the lowest which was visible. The limestone,
(No. 1.) though in thin plates, and
intermixed with quartz, was exactly similar
to the lower limestone on the lake of Annecy;
it was a lightish grey intermixed
with red, and highly indurated. The talcous
schist (No. 2.) was a thick bed, interstratified
with soft talc, which was decomposing
and friable, forming a saponaceous powder.
The limestone above it (No. 3.) was very
highly indurated, from an admixture with
quartz; in other respects it resembled No. 1.
The soft earthy gyps of No. 4. and No. 7.
were similar ; they were white, and much
intermixed with green talc or steatite. The
red and grey anhydrous gypsum (Nos. 5.
and 6.) were also spotted with the same.
But the most remarkable circumstance is
the occurrence of a thin stratum of carbonaceous
matter in the midst of a bedof gypsum,
at least thirty feet in thickness. I do not