TIEGS (CIID ES, AIMMD JEXCOUIE® JEILOCKES, SEINE 729 
selves. Such we do find. All of the cliff strata show evi- 
dence of great pressure; they are fractured and often traversed 
thickly with calcite veins (especially the harder Haupt-Dolomite 
and the Tithon); the less brittle rocks are strongly contorted 
and full of cleavage structure and of slickensides (especially the 
softer Tithon beds of the cliffs); certain of the less resistant 
beds (as the Aptychus limestone and Raible marls on the 
Roggenstock and Laucheren) are greatly thinned by pressure or 
in places entirely pinched out. All these features are evidence 
of strong pressure, but more striking is the further fact in this 
connection, viz., that all evidence of disturbance, such as is 
found in the cliff masses and I may also add in the larger exotic 
block masses near the cliffs, is entirely wanting in the Helvetian 
“strata all about. It might of course be said that the evidences 
of pressure mentioned would be as well accounted for if the 
cliffs were thrust powerfully upward from below through the 
younger Swiss strata upon which they le, as has been thought 
by Professor Neumayr to be the case with the Carpathian cliffs. 
But at Iberg and in the other larger cliffs in the region of the 
Lake of Lucerne it is hard to see how such an upward thrust 
could have taken place powerful enough to force masses half a 
mile long through beds of limestone (Urgonkalk, Gault and 
Cenoman) several hundred feet thick without showing some 
evidence of the disturbance in the rock thus thrust through at 
least in the immediate vicinity of the cliffs. Such evidence, 
however, we fail to find either in the alteration of the general 
strike or dip of the Swiss beds or in indications of pressure in 
the minute structure of the rock itself. This contrast indicates 
that the one set of rocks has undergone disturbance which the 
other has not, and that the two have been affected by a differ- 
ent set of dislocations. In the Roggenstock near Iberg the 
cliff strata lie nearly horizontal. The Swiss strata below them 
are also nearly horizontal at this place. This position is what 
we would expect were the cliff thrust from the side, but very 
difficult to understand if they were thrust from below. The 
long, low mass of the Laucheren-MGrdergrube cliff presents also 
the same difficulty on the latter hypothesis. Again the strata 
