204 CRUISE OF THE NEPTUNE 



series. A fine to medium-grained rock, usually somewhat foli- 

 ated, and composed largely of dark-red feldspar with much 

 mica, little hornblende and quartz, cuts the foregoing gneisses, 

 and probably was the granite which altered them by intrusion to 

 their present state. The basic intrusive rocks are represented 

 by dark-green diabase, or its alteration products, dark horn- 

 blendic and chloritic schists and gneisses. Taken as a whole, 

 this series of specimens would answer for any of the typical 

 Laurentian regions of northern Canada. 



At Cumberland gulf the rocks were examined at Kaxodluin 

 on the south shore, some twenty miles from Blacklead station ; 

 also at Blacklead and at Kekerten islands. At Kaxodliun 

 light and dark-coloured mica schists and gneisses were found, 

 cut by a light-pink mica-granite-gneiss. The dark schistose 

 rocks were decomposed near the surface, and contained a con- 

 siderable amount of disseminated pyrite. Between this place 

 and Blacklead the ship followed the shore-line closely, so that 

 the prevailing dark, rusty gneisses were distinctly seen. 



The most abundant rock on Blacklead island is a coarse- 

 grained, pink mica-granite-gneiss, containing large feldspar 

 crystals. This cuts, and is foliated with, coarse, dark mica- 

 schists, and finer-grained lighter-coloured quartzose gneisses. 

 Some of the dark schists contain flakes of graphite, and this 

 mineral is said to be abundant in places on the islands and 

 shores of the gulf farther to the westward, where attempts have 

 been made to work some of the mica and graphite deposits, with- 

 out much success. 



At Kekerten similar gneisses are found, along with large 

 masses of diabase and greenstone, somewhat decomposed near 

 the surface, where it weathers reddish. 



At Frenchman cove at the head of Cyrus Field bay, the 

 prevailing rock is a coarse-grained, red mica-granite-gneiss, 

 associated with bands of coarse mica-schist. 



