32 ASSINNlBOINE AND SASKATCHEWAN EXPEDITION. 



intersected with quartz veins. The rock on Sugar Island 

 is exposed on one side in the form of a precipitous cliff 

 20 feet high. On the opposite side it slopes gradually to 

 the water's edge. 



We went out of our course to visit the gneissoid islands 

 before referred to. The first island bore nearly due east 

 of Sugar Island. It consists of gneiss with rose coloured 

 felspathic veins, pursuing a general direction of S. 40° E. 

 The axis of the island is also S. 40° E. ? and the gneiss is 

 intersected by fissures nearly at right angles to one 

 another, one set bearing S. 20° — 40 E. The surface of 

 the gneiss on the highest point, which may be 23 feet 

 above the lake, is polished and furrowed in a direction 

 S. 55° E. The south-east shore is precipitous, the oppo- 

 site sloping. 



The second island consists of a dome-shaped mass of 

 gneiss with large quartz veins meandering through it. 

 The third island, within a few yards of the first and 

 second, shows far less metamorphic action, and with a 

 strike S. 15° W., has a dip 75° from the vertical. It is 

 precipitous to the N.W. and slopes to the S.E. 



Proceeding along the south-west coast we found a 

 barrier of beaches along the shore about 300 yards dis- 

 tant from it, on which boulders of the partially meta- 

 morphosed sandstone and gneiss were piled up, farther on 

 were worn and large unworn fragments of a siliceous 

 limestone, which, however, was nowhere found in posi- 

 tion. The occurrence of these gneissoid islands in a flat 

 limestone country is very interesting ; the metamorphosed 

 sandstone shows that the epoch of their elevation must 

 have been before the deposition of the limestone found 

 on Thunder Island, to which we next proceeded, and 

 after the deposition of the sandstone on Sugar Island. 

 The three gneissoid islands, having no name, we called 



