1848.. MURCHISON ON THE STRUCTURE OF THE ALPS. 207
tion of the chalk of North Europe and of the scagha of North Italy,
is of very considerable thickness, certainly several hundred feet.
The largest superficies in which the inoceramus limestone is ex-
posed, is around the dome-shaped masses, the external faces of which
dip rapidly dowT^i into the great ravines north-east and east of Burg-
berg. In the latter we perceived it to be overspread by a thin course
of dark greyish, fatty marl, in which we detected one inoceramus.
This band is immediately surmounted by marly and incoherent,
slightly micaceous, thin-bedded sandy shale, which here has been
largely denuded, and above Burgberg is exposed in a transverse de-
pression between the Griinten mountain on the one hand and the
lower nummulitic ridges on the other.
This hollow space (the Yust) between the external face of every
stratum to which the terms * chalk' or * cretaceous' can rigorously
be applied, and the lowest band of nummulitic limestone, is occupied
in its lower portion by the small micaceous shale and schist before
mentioned, which is succeeded by a greenish sandstone associated
with impure greyish limestone and dark grey shale. These beds,
particularly the sandy impure limestone, contain the same Gryphcea
vesicularis which has been remarked as lying between the inoceramus
limestone and the nummulitic rocks of the Fahnern in Appenzell.
Here, however, this intermediate band of green sandstone, schist
and limestone .e of the diagram) is vastly more expanded. If the
section be made in the regular ascending order of the mountain
(fig, 17), as followed from its main escarpment, over its summits,
down the Gundalpe, and across the Vust to the nummulitic ridges
east of Burgberg, this intermediate group (e) is seen to be perfectly
conformable to the inoceramus limestone beneath it, and to the lowest
nummulitic rock above it. Equally is it conformable if another
section at right angles to the above be made from the Griinten to
the valley of the Starzlach, a little to the south of the chief mines,
and where a rivulet descends from the mountain (see fig. 18). In
Fig. 18.
The Griinten.
Cretaceous. Nummulites. Flysch.
Starzlach.
-;p S.E.
V
N
babcdefff g
this section the beds are more nearly vertical, and necessarily occupy
very small horizontal spaces. The same order being followed from
centre to flank, i. e. from the neocomian through the greensand
and cretaceous strata, the explorer does not fail to observe a great
thickness of bluish grey, slightly micaceous marls, and marlstone
associated with a sort of greensand, and beds of impure grey lime-
stone with white veins (e), in which we again detected the same Gry-
pheea as in similar strata in a like position in the other section near
Burgberg, p. 205.