M. Studer on the Geological Structure of the Alps. 151 



condary rampart, and the baths of Leiik are situated between 

 the two chains of sedimentary rocks. At the eastern extremity 

 of the group of Mont Blanc, from Saillon to Sion, we can 

 reckon four or five parallel chains of limestone and of fiysch, 

 all of which have their escarpments turned towards the central 

 mass, while they present a gentler declivity to the east. 



We frequently see appearing, at the base of the first lime- 

 stone rampart, gneiss and quartzite, which rise sometimes to a 

 very great height, as, for example, at Hofi^, near Imgrund, at 

 Gadmen, at Maderan, &c. and which plainly prove that the 

 origin of the valley is here more recent than the event, what- 

 ever it may have been, which placed the calcareous beds in 

 their present relations with the gneiss, and that, therefore, the 

 formation of the valley cannot be attributed to a plutonic 

 soulexement of the gneiss, which would have caused the upper 

 limestone covering to disappear. The same phenomenon is 

 more distinctly observable on the opposite side of the valley ; 

 we there see calcareous masses of more than a thousand feet 

 in thickness, covered by the same gneissitic quartzite which 

 serves as their base ; and, when we follow the transverse val- 

 leys which penetrate into the central mass, we see the limestone 

 entangled in the gneiss, and forming wedges of many leagues 

 in extent (see the section, Plate I.). This is what takes place 

 in the Mettenberg, and in a more striking manner in the Laub- 

 stock and Pfaffenkopf, on the two sides of the entrance to the 

 valley of Guttanen. It is evident that before the formation 

 of the valley, these wedges of limestone communicated with 

 the limestone of the other wall, and that they were then, as 

 at present, surrounded by the gneiss. The old surface of the 

 ground reached at that period a great elevation above the 

 valleys of the present day, and these valleys, which in a great 

 measure seem to owe their origin to subsidences, have crossed 

 the gneiss and the limestone without changing the relative 

 position of these two rocks. It is sufficient to witness these 

 phenomena in nature to be convinced of this. But further, 

 the magnificent sections of the valley of the Rotthal, and of 

 the Col d'Urbach, furnish us with the proof of this opinion ; 

 for there, where the subsidence perhaps encountered difficul- 

 ties in consequence of this entanglement of the limestone and 



