WZ LATLE[ O ORIN ATO LM GTAOTEO (Gave 
much more extensive cap covering the outer Alpine chains. 
Were the cliff masses thrust upward from below through the 
Helvetian Cretaceous and Tertiary anticlines we could hardly 
expect to find so much eroded material derived from them as we 
do indeed find in the Nagelfluh. For in that case we should 
expect the cliff masses to be in some places less completely 
thrust through the encasing younger strata, and therefore more 
or less completely hidden by them, so that the cliffs would 
become exposed to its action only after erosion had removed 
the younger covering. We should therefore expect to find the 
cliff masses increasing in number and extent as deepening ero- 
sion exposed them more and more to view. We find, however, 
abundant evidence that the cliffs cover a much less extensive 
area today than formerly. Again in case of an upthrust from 
below we should further expect that the percentage of cliff 
strata in the material carried from the surface by erosion would 
have been less in former times than it is today —it could surely 
not have been greater. An examination of the stream beds 
coming from the cliff belt shows today a decided preponder- 
ance of Helvetian over cliff strata in general. Instead now of 
finding in the Nagelfluh, as we would expect an even greater 
preponderance of Helvetian over cliff strata we find the amount 
of Helvetian rocks insignificantly small. This striking fact can, 
as it seems to me, only be explained on the ground that the 
Helvetian strata were at the time of the deposit of the Nagel- 
fluh to a considerable degree protected from the erosion which 
attacked and carried down to the Miocene seashore vast quantities 
of cliff material. To assume that the protection consisted in a 
cap of cliff strata which covered large portions of the outer 
chains would be in harmony with the theory of overthrust but 
seems to be quite inexplicable on the hypothesis that the cliff 
masses were pushed up through the strata where they occur. 
With this imperfect summary we have endeavored to give 
some of the more important reasons for believing that the Swiss 
cliffs are superficial phenomena lying upon the surface of the 
normal Swiss series and immediately upon the Flysch and have 
been therefore thrust from the side into their present position. 
