Gaal THE JOURNAL OF GEOLOGY. 
cias and conglomerates of early Tertiary (Eocene) and every- 
where known under the name of Flysch. The thickness of the 
whole is, because of complicated movements which have taken 
place and the monotony of,its petrographical characters, very 
difficult to determine. It has at some points been pinched out 
to a few feet ; at others it is apparently several hundred feet in 
thickness. 
This formation known as the Flysch is of especial interest to 
us because it is in it that the ‘cliffs’ occur. The geological 
term ‘‘Klippe” or cliff, if we translate the term, was originally 
applied on account of the striking and abrupt manner in which 
these masses rise above their level or gently rolling Tertiary 
(Flysch) surroundings like cliffs above a beach. As geologists 
have learned more of the true nature of these masses, the term 
has come to take on a more definite geological significance, and 
is now somewhat loosely applied to island-like masses of rock 
which are stratigraphically, paleontologically, petrographically, 
and usually orographically foreign to the region in which they 
occur. Thus the Mythen overlooking the Lake Lucerne a short 
distance east of Brunnen and the Rigi are good types of the class 
— isolated masses, striking in appearance and composed of strata 
which have been found zz szf#u nowhere else in all Switzerland. 
To the rocks found in the cliffs the term ‘‘exotic’’ has been 
applied to express their foreign nature and to distinguish them 
from the ‘‘erratic” material brought down by the glaciers. 
The exotic material of the cliffs consists of masses of dolo- 
mites, marls, shales and sandstones in certain of which charac- 
d 
teristic Triassic and Jurassic fossils have been found. It lies upon 
or more or less imbedded in the soft Tertiary Flysch shales and the 
masses of it range in size from the smallest angular fragment up 
to cliffs a half mile and more in length and several hundred feet 
in height.1 Of these the smaller blocks which were obviously 
loose, disconnected masses have been long known as ‘‘the exotic 
blocks” of the Flysch, while the more pretentious masses which 
on account of their size were apparently in situ, were termed 
«For comparison y. Neumayr’s description of the Carpathian cliffs which are often 
much larger than this. Erdgeschichte, Leipzic, 1887, Vol. II., p. 672. 
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