TIES, (CILIUAIES AMID SIZQOUMC SEL OCKS, JEINC: WBS 
Origin of the cliffs—\WVe now approach another, perhaps the 
most difficult question relating to the cliffs—the question of 
their origin. As the cliff masses themselves do not furnish us 
direct evidence of the direction from which they may have been 
thrust, we are led to look for other and indirect evidence. The 
solution of this problem must depend therefore in great part 
upon the study of the faunal characters and relationships of the 
exotic strata, in connection with the stratigraphy, their petro- 
graphic characters and their distribution. An important circum- 
stance and one which has probably retarded more than anything 
else the acceptance of the idea of overthrust, is the fact that, in 
distinction from the analogous phenomena in France, Scotland 
and America, in Switzerland no rock masses are known which 
contain zz sztz the strata and fossils found in the cliffs and whence 
therefore the cliff masses could be supposed to have proceeded. 
It has seemed therefore quite impossible to trace them to their 
original home or basin of deposit. In looking for the basin of 
deposit of the cliff series the region to the south of the cliff 
zone is soon seen to be excluded for reasons already indicated, 
viz., that the faunal and other characters of the exotic series 
are so entirely distinct from those of the Helvetian series which 
occupy all the district of the Glarnese Alps to the south, and 
although to the south still further strata bearing the same facial 
characters are known in the vicinity of the Italian Lakes the 
extreme distance of these outcrops, sixty-five miles or more, as 
well as the physical character of the intervening Alps, effectually 
precludes the possibility of deriving the cliffs from that quarter. 
As the cliff masses were evidently not introduced from the east 
or west we are led to look to the plains to the north (schwei- 
zer’sche Hochebene). Many years ago the famous Swiss geol- 
ogist Studer for reasons quite different from those here considered 
was led to believe in the existence of a sunken mountain system * 
buried beneath the young (Miocene) strata of the Swiss plains 
which has since been assumed to exist by numerous other geol- 
ogists and has received the name of ‘‘das Vindelisische Gebirge”” 
from Professor Gimbel. 
*Cf. Profiles in STUDER’s Geologie der Alpen, Vol. IL., p. 434-436. 
