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Bemarks on the Geological Belations of the Gneiss of the Alps. 

 By Professor B. Studer of Berne. (From a Private Let- 

 ter addressed to Professor J. D. Forbes.) 



** I think that I have obtained a precise and decisive result 

 with respect to the great question of the stratification of 

 gneiss, which has so long occupied me. From what we saw 

 at the Mettenberg and in Urbach, it is perfectly evident, that 

 the direction of the laminae of gneiss is independent of what 

 is called stratification, that is to say, that it is not an effect 

 of gravity, that these slaty rocks have not been elevated from 

 a horizontal position into the vertical one in which we now 

 find them ; that the great mountain masses with a fan-like 

 stratification have acquired this structure as an effect of crys- 

 tallization, or of other forces independent of gravity. You 

 are aware that the calcareous mass of the Mettenberg forms 

 a wedge in the gneiss, and that, in the valley of Urbach, seve- 



ral wedges of limestone and gneiss are fitted together ; but 

 in the two localities the slaty structure of the gneiss does not 

 shew the least dependence on the limits or form of these 

 wedges. The dip is to the south, under an angle of 50°, 

 while the limit of the gneiss and limestone is horizontal. To 

 maintain the opinion of the elevation of the gneiss, would be 

 to suppose that this rock was older than the limestone, and 

 that the latter was introduced into the crevices of the mass 

 of gneiss ; a supposition which is inadmissible. But if, on the 

 one hand, I am satisfied that the theory of the origin of our 

 mountains of gneiss by the tilting of the strata [par redresse- 

 ment) is erroneous, I am far from being able to give a better 

 one. Supposing the gneiss to be schistose lava, we must be 

 surprised to find so little change in the limestone inclosed in 

 it or in contact, whilst, in contact with granite and other 



