vi MOUNTAINS 223 



Appenzell, and Bregenz on the Lake of Con- 

 stance, is the lowland occupied by later 

 Tertiary strata ; between this second line 

 and another passing through Albertville, St. 

 Maurice, Lenk, Meiringen, and Altdorf lies a 

 more or less broken band of older Tertiary 

 strata ; south of which are a Cretaceous zone, 

 one of Jurassic age, then a band of crystalline 

 rocks, while the central core, so to say, of the 

 Alps, as for instance at St. Gotthard, consists 

 mainly of gneiss or granite. The sedimentary 

 deposits reappear south of the Alps, and in 

 the opinion of some high authorities, as, for 

 instance, of Bonney and Heim, passed con- 

 tinuously over the intervening regions. The 

 last great upheaval commenced after the 

 Miocene period, and continued through the 

 Pliocene. Miocene strata attain in the Eighi 

 a height of 6000 feet. 



For neither the hills nor the mountains are 

 everlasting, or of the same age. 



The Welsh mountains are older than the 

 Yosges, the Yosges than the Pyrenees, the Pyr- 

 enees than the Alps, and the Alps than the 

 Andes, which indeed are still rising ; so that 



