File:The Quarterly journal of the Geological Society of London (13204794655).jpg

404 C. CALLAWAY ON THE NEWER GNEISSIC
to the same bed of quartzite, but overlaps the edges of several beds
within a few yards. We are not, however, left to such minute
points of criticism. Here, again, our knowledge of the Assynt
succession solves the difficulty. The beds of quartzite in contact
with the gneiss are of the Seamy type ; and lower down the slope the
upper (Annelidiau) division comes in. Further west, at the corner
where the cliff curves abruptly round to the south, the Erown Flags
appear below the Annelidian ; and below the flags, at the base of
the escarpment, the Annelidian comes in again. This structure is
similar to the inverted syncline on Camas-an-Duin, the Salter etta-
grit and Dolomite being absent from the centre of the fold, as in
Cr aig-n a-f aolin .
The same relations are continued for some distance along the
strike- section (fig. 10). The ground now rising towards the south,
Fig. 10. — Strike- Section of the western escarpment of Ben Arnaboll*
(Scale 8 inches to 1 mile.)
N. S.
the Quartzite under the flags is soon hidden, and the flags occupy the
base of the cliff. Then suddenly the Quartzite (about 200 ft. thick)
above the Flags disappears, and the latter form the whole of the
scarp below the gneiss, the Quartzite and Flags being separated by
a vertical fault, except at the top, where the Flags send a narrow
wedge to the north, between the Quartzite and the gneiss. Further
south the place of the Flags is taken by confused masses of quartzite
and flags ; but just above the little loch the succession is clear.
The cliff at this spot from its foot to the base of the gneiss is
200 feet high. It displays an exact repetition of the Assynt series
from the bottom of the Flags to the lower part of the Dolomite.
Quartzite lies at the foot of the scarp. Ascending over the Flags,
in which we can make out three horizons, at 60 feet we reach the
S alter ella-grit and Quartzite, and at 90 feet we come to the base of
10 ft. of dolomite. At 100 feet the Flags rest on the Dolomite, the
lower rock dipping E.S.E. at 40°, and the Flags at 30°, the beds of
dolomite being curved outwards as if by the pressure of the over-
lying flags. The second 100 feet is the lower succession repeated,
even to the 10 feet of dolomite. It will be observed that in this
section the rocks are not inverted.
The faulting here is not normal ; for the repeated series rests on
the lower one in a steep cliff, but is clearly reversed. The westerly