GEOLOGY 205 



At Cape Haven station near the northern entrance to the bay, 

 pink and gray mica-gneiss prevails, and is cut by many large 

 dikes of red pegmatite composed largely of perthite, with some 

 quartz and mica. Schists forming one of the islands of the 

 harbour contain any well-developed crystals of pyrite, up to an 

 inch cube. 



The northern and eastern sides of Bylot island appear to be 

 wholly formed of crystalline rocks, without any of the capping 

 limestones found upon the other islands of Lancaster sound. 



ISLANDS OF GKOUP HI. 



This group contains the large islands of Bank, Victoria, 

 Prince of Wales, North Somerset and King William, all situ- 

 ated south of Lancaster sound and west of Prince Regent inlet. 

 North Somerset alone was visited by the Neptune; all geologi- 

 cal information concerning the others being from the observa- 

 tions made by the several parties engaged in the search for the 

 Franklin expedition. 



Dr. G. M. Dawson collected this information from the narra- 

 tives of these search expeditions, and printed a concise summary 

 of it in his report on the northern portions of the Dominion, 

 from which the following notes have been taken : 



' Archaean rocks are found only on Prince of Wales and 

 North Somerset islands, where a spur from the great mass of 

 crystalline rocks forming the northeastern mainland extends 

 northward through the peninsula of Boothia and forms the land 

 on both sides of Peel sound. 



( The granitoid rocks are again found on the west side pf 

 North Somerset, where they form the eastern boundary of Peel 

 sound. Boulders of the granite are found at a considerable dis- 

 tance (100 miles) to the northeastward of the rock in situ, as 

 at Port Leopold, Cape Rennell, &c. The general characters of 

 the granitic rocks in the north and west of North Somerset are 



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