BY \V. N. BKNSON 



565 



displaced between two faults. The main mass of the intrusion, 

 occurring on the top of the ridge, contains large and abundant 

 phenocrvsts of albite. These decrease in size as the rock is 

 traced to the south, and the rock at the same time becomes 



more 



Fig.4.— Sketch Map of the East Gap Hill Complex, 

 and more vesicular; it begins to take on a reddish tint: fragments 

 make their appearance, and imperceptibly one passes into breccias 

 and agglomerates, composed of more or less ferruginous kerato- 

 phyreror spilites, in which the ferromagnesian minerals have 

 been destroyed, leaving only a red staining of haematite. These 



