102 0)1 the Formations of the Western Siviss Alps, 



2. Metamorphic rocks. These are gneiss, mica-schists, schis- 

 tose protogines, &c. These rocks rest, in an irregular man- 

 ner, on the crystallised formation. 



3. Pudding-stone, or the Valorsine system, in large strata, 

 often containing anthracite. In general, this system is 

 formed at its upper part by schists, sandstones, or very ar- 

 gillaceous limestones, exhibiting many impressions of ferns. 

 Sometimes these latter rocks are wanting, because, in great 

 upheavings, the argillaceous rocks ai-e more easily compressed 

 than the others, and disappear. 



I have not hitherto observed in Savoy any discordance be- 

 tween this anthracitic system and the metamorphic rocks.* 



4. Above the Valorsine system come the limestones, and 

 the more or less argillaceous schists of ih.Q Jurassic formation, 

 terminated at the lower part by a bed of Cargneule, or cellu- 

 lar magnesian limestone. This Jurassic formation has a 

 stratification not conformable with that of the Valorsine sys- 

 tem ; and may be seen on the right bank of the Rhone, be- 

 tween Bex and Martigny. The valley of the Rhone there 

 forms an immense section, very nearly perpendicular to the 

 dii'ection of the formations of the Alps. We there observe 

 that the crystalline and metamorphic formations form two 

 parallel chains, which run under the secondary formations of 

 the northern chain of the Valais. 



The Valorsine system is compressed between the two 

 chains, and covers them only in part, while the cellular mag- 

 nesian limestone, surmounted by the Jurassic formations, en- 

 velop them entirely ; and it may be said that these forma- 

 tions, notwithstanding the accidents to which they have been 

 subject, form a kind of vault, which extends from the baths 

 of Lavey to Saillon, in the Valais, and rises in the mass of 

 mountains crowned by the Dent de Morcles. 



The stratification of the Jurassic formations, moreover, is 

 transgressive in isolation to that of the Valorsine system. 



5. The cretaceous formation rests on the Jurassic formation. 

 It is divided in the following manner : — 



* This discordance, however, has been pointed out in the Alps of Dauphiny. 

 See Bulletin de la Societe Geologique de France ; meeting at Grenoble, 184:0, XL, 

 and my Menwir on the Anthracites of the Alps. 



