252 M. Broxgniart on the 



The principal mountains to which the fallowing statement 

 may be applied, are the Montagne de Varens, the Dent de 

 Morcle, the Montagne de Sales, and the Rocher des Fis in 

 the valley of Servoz : * I shall speak principally of the 

 latter. 



The Montagne des Fis, crowned by the rocks of the same 

 name, precipitous towards SerToz for a considerable part of 

 its height, and covered by the debris of the upper parts, is 

 connposed of numerous beds, which, from Servoz, appear 

 nearly horizontal, because they incline from S.E. to N.W. 

 The rocks forming these beds are calcareous and schistose, 

 mixed with hornstone and flinty slate; they belong, as I 

 have elsewhere stated, + to the transition class. But the 

 description of the rocks composing this mountain having 

 been foreign to the memoir in which I mentioned them, I 

 omitted it. I shall therefore insert it here, in order better 

 to expose the mineralogical and zoological differences that 

 are perceptible between the base or lower part of this moun- 

 tain, which belongs to the transition series, and the upper 

 portion, which I refer to the chalk formation. 



The Montagne des Fis, from its base in the valley of la 

 Diosa, opposite Servoz, to that part of its summit which I 

 visited, is composed of micaceous clay slate, compact lime- 

 stone, of a blackish or deep smoke grey colour, and of differ- 

 ent varieties of sandstone (psammite) ; but these rocks are 

 covered, on many points of the southern face of the moun- 

 tain, by immense fallen masses, which increase daily ; these 

 masses of debris conceal part of the beds which compose the 

 mountain, and the cause which produced them appears to 

 have been sufficiently powerful to allow entire masses of 

 rocks to slide down without perceptibly deranging their 

 structure, so that it would require a scrupulous and long ex- 

 amination of this mountain, to be certain that the masses 

 or escarpments observed in the ascent, really follow each 



• I visited these rocks in company with M. Laine, in 1817. 

 + Memoir on the relative position of the serpentines &c, in the Apen- 

 iiiaes. 



