GEOLOGY 209 



The specimens from the Laurentian area, which extends 

 southward from Hayes sound to Cape Isabella, were collected 

 at Capes Sabine and Herschel. The specimens from both locali- 

 ties are very similar, the prevailing rock being a moderately 

 coarse-grained granite, of a dark-red colour, composed largely 

 of red feldspar and bluish quartz, with a small quantity of bio- 

 tite in diminutive scales. These rocks are only slightly 

 foliated in a few places. 



The specimens from the Laurentian measures beneath the 

 Silurian limestones at Cuming creek show a greater variety. A 

 red gneiss, varying in texture from fine to coarse, predominates. 

 It is composed largely of feldspar, with quartz and considerable 

 biotite. It cuts a lighter-coloured, more quartzose gneiss, and 

 also bands of dark mica-diorite-gneiss. 



