570 



DE. C. S. LIT BICHE PBELLEE ON GLACIAL [Aug. 1896, 



that of Au the peculiarity of being situated in a zone of subsidence^ 

 with which I propose to deal farther on. 



Schindelleggi. — This locality derives especial interest from the cir- 

 cumstance that here the river Sihl was deflected from the drainage- 

 area of the Zurich valley by enormous accumulations of glacial deposit, 

 of which there are several remarkable exposures. As is seen from 

 the sketch-map (fig. 8), the junction of the Sihl with its two* 

 affluents, the Biber and the Alp, is about 2 kilometres above 

 Schindelleggi, although the points of confluence have evidently beeifc 



i 



I 



oo* 



repeatedly barred and shifted in the course of successive glaciations. 

 Above the confluence, all the three rivers flow parallel to each other 

 and to the strike of the Alps, through flat, broad, and very ancient 

 valleys, subsequently filled to a considerable depth with glacial and 

 fluviatile deposit ; while below the confluence, as far as Schindelleggi, 

 the Sihl has eroded its present bed deeply in moraine, the Molasse 

 only appearing again at the point of deflection near that village. 

 Even in that section, however, the river does not now run in its 



