224 THE ANDES OF SOUTHERN PERU 



or fifteen feet. The greater fissility of the schists as contrasted 

 with the shales on the opposite or eastern margin of the batholith 

 caused them to be relatively much more passive in relation to the 

 granite magma. They were not so much torn off and incorporated 

 in the magma, as they were thoroughly injected and metamor- 

 phosed. Added to this is the fact that they are petrographically 

 more closely allied to the granite than are the shales upon the 

 northeastern contact. 



