ZURICH AND GLARUS. 
I7I 
halt at Wadenschwyl and Rapperschwyl, forming 
moraines, the latter of which reaches almost to the 
water-level, and has been utilised for the railway. 
It bears a number of erratic blocks, some, and in- 
deed when the water is low many, of which project 
above the water-level. 
The Lake of Zurich then is a drowned river 
valley dammed by a moraine. The valley of the 
Linth, as the Upper Limmat is called, is a cross 
valley, the upper lake from Utznach to Richterswyl 
is longitudinal, the upper portion of the lower lake 
crosses the strata somewhat diagonally, while the 
rest of the lake and the Lower Limmat is again a 
cross valley. 
On both sides of the Lake of Zurich are a 
series of terraces. They are especially conspicuous 
from Meilen to Stafa, and at Horgen (see vol. i. 
p. 214). 
The valley itself, like the others which cross the 
Swiss low country, no doubt commenced in pre- 
glacial times. During, if not before, the first inter- 
glacial period it was excavated to its full depth, i.e. 
considerably below the present level, and partly re- 
filled during the Second Glacial period. In pre- 
paring the foundation for the quay bridge at Zurich, 
the glacial deposits were pierced to a depth of 
