i 
10 T. 8S. Hunt on Alpine Geology. 
and mica-schist, and of quartz veins holding tourmaline. The ‘ 
paste, which is reddish, talcose and micaceous, seems identical : 
with many of the pebbles, so that it is sometimes difficult to : 
distinguish these from the matrix. A thin fibrous envelo 
often surrounds the pebbles (§$ 521). Although the alternation : 
lower limit of this formation on account of the great resem- 
less we take care we run the risk of being deceived 
PPM ae a SE eT ee ee ee Sd 
confounding it with gneiss,” while elsewhere similar rocks 
ass 
ume the aspect of granite from the predominance in them of © 
enclosed pebbles, appears according to Favre to have undergone 
.. See Favre, Terrains liassique et keuperien, etc. (1859), pp. 78, 79, to which in 
his work he refers the reader for further peta on tei pain : 
