XIV.] THE GEOLOGY OF THE ALPS. 339 



yet fully recognized. The suggestions of Bergmann and Ber- 

 trand, that the crystalline rocks of the Alps are newer than the 

 fossiliferous limestones which pass beneath them, seems to have 

 been the first attempt to give to Hutton's view a definite and 

 special application, and the inception of that hypothesis with 

 which we have since become familiar, which supposes the con- 

 version of mountain masses of palaeozoic, mesozoic, and even 

 cenozoic sediments, in the Alps and elsewhere, into gneisses and 

 other crystalline rocks.* Numerous sections in the vicinity of 

 Mont Blanc show the sedimentary strata in their normal atti- 

 tude, resting unconformably upon the crystalline schists, while 

 in some localities the whole succession from the carboniferous 

 to the eocene, both inclusive, is met with. In many parts, 

 however, the carboniferous is wanting, and the trias forms the 

 base of the column, while elsewhere the infra-liassic beds re- 

 pose on the crystalline schists, and in the Bernese Alps no 

 fossiliferous beds lower than the oolite ar ^served. These 

 variations would appear to be connected with the movement of 

 subsidence which permitted the deposition of marine limestones 

 above the carboniferous strata ; and Favre has further pointed 

 out, in the vicinity of Dorenaz, a want of conformity between 

 these and the succeeding formations. 



To the carboniferous belongs the well-known conglomerate 

 of Yalorsine, which includes pebbles of gneiss, quartzite, talcose, 

 and micaceous schist, and of quartz veins with tourmaline. The 

 paste, which is reddish, talcose, and micaceous, seems identical 

 with many of the pebbles, so that it is sometimes difficult to 

 distinguish these from the matrix. A thin fibrous envelope 

 often surrounds the pebbles ( 521). Although the alternation 

 of these beds with otnu^s holding plants shows them to be of 

 carboniferous age, it is c c ten, says Favre, difficult to fix the 

 lower limit of this formation, on account of the great resem- 

 blance between certain of the carboniferous sandstones and 



[* Already, before Hutton, Von Trebra, in 1785, had taught a somewhat similar 

 doctrine. He supposed that a slow change under the influence of heat and water, 

 which he compared to a fermentation, is constantly going on in the interior 

 of the rocks, and may in time convert mountains of granite into gneiss, and of 

 gray wacke into clay-slate. (Erfahrungen von Innern der Gebirge, page 48. )] 



