80 GLACIOLOGY 



porphyritic gneiss. This has been cut by veins of fine-grained reddish granite with 

 green mica. These veins in turn have been intersected by coarse red aphtes. The 

 patch at the top left-hand side of the block is not another variety of rock, but simply 

 another face of the boulder. 



If this greenish-grey porphyritic gneiss is of the same age as the gneissic 



Fine groined reddish granite 

 H'/th green mica. 



Coarae red 

 epiite 



DarH greenish grey 

 porphyritic gneiss 



Fig. 38 



granite of Cape Ross, and the latter is the equivalent of the gneissic granite of 

 Depot Island, we have here evidence of the following succession amongst the 

 eruptives, the oldest being mentioned first : — 



1. Basic sphene-diorite. 



2. Grey gneissic granite. 



3. (a) Fine-grained reddish granite with green mica ; (6) coarse red aplite. 

 These last two rocks probably belong to the important group of the red granites 



so widely distributed along this coast. 



The next sketch, at about 11 miles south of Depot Island, is taken from the sea 

 ice off Gregory Point. 



BonneyGlaaer 



Piedmont Ice 



• CapaCragM; 



Fig. 39 



It shows the general appearance of the piedmont aground, resting on its low- 

 lying coastal platform, formed here of intensely glaciated granite. It has a width 

 here of about 7 to 8 miles. 



