ancieiU Gj/psum of the Alps. 71 



rous clay ; and these latter gypsums are kno^vu to be gene- 

 rally considered as of decidedly secondary formation. 



These resemblances are sufticientiy remarkable; I do not 

 pretend to conclude from ii an identity of geological forma- 

 tion between these ancient secondary gypsums of Germany 

 and the gypsums of the Alps, even those in insulated super- 

 ficial masses ; but they may one day serve to establish re- 

 lations between the different terms of the seiies of rocks, 

 the formation of which has followed that of the primitive. 

 I shall hereafter return to the subject. 



6th. Sulphur also exists in the gypsum of the Alps ; it 

 forms nests of rare occurrence, and of small size, in the mass 

 of the gypsum. It has been found in that of Bex, at Pesey, 

 at Gebrulaz, &c. : there occurs at AUevard a lamellar an- 

 hydrous sulphate of lime, which is penetrated by sulphur, 

 giving it a yellowish tint. 



I might also notice anthracite, some traces of which are 

 found in the gypsum of Brides near Moutiers ; but from 

 this example a very positive consequence cannot be drawn 

 as to the identity of the position of the gypsum and antiira- 

 cite, this substance only occurring in very thin small veins, 

 between the laminae of the gypsum, in portions near the sur- 

 face : which may lead to the presumption that it has been 

 afterwards deposited by infiltrations from the water of the 

 upper rocks, which contains large masses of anthracite. It 

 will hereafter be seen that I have obtained more probable 

 data of the existence of the gypsum of the Alps and anthra- 

 cite in the same formation. 



B. Geological positions of the Gypsums of the Alps. 

 1. In the Tarentaise (Savoy). 



I have always observed the gypsum of the Tarentaise on 

 the surface, and as I have already said, in such a state of 

 decomposition that it was impossible to judge, in a rigorous 

 manner, of its geological relation to the other rocks. It 



