GNEISS OF THE CATHEDRAL ROCKS. 
31 
some are pink granite, and both kinds are more abundant towards the eastern 
end of the exposure. Here the pink rock displays augen-structure (716), and 
occasional isolated patches and wisps of the ordinary foliated gneiss were observed 
in the middle of the masses of augen-rock. The dykes form a rough network 
over the face of the gneiss, and their thicknesses vary from 6 inches to 12 feet. 
The most prominent consists of a pink quartz-porphyry (709), cutting through the 
gneiss perpendicularly to the foliation. The gneiss here is dark in colour, and its 
alternating laminae are usually under a quarter of an inch in thickness. These 
foliations are themselves folded into series of anticlinal or isoclinal folds, with 
amplitudes of about 8 feet, the various bands remaining parallel. 
Other specimens from later veins or dykes traversing the augen-rock may be 
mentioned, namely : — • 
(1) A green actinolite-rock (725). 
(2) A white pegmatite-vein (723). 
(3) A thin seam containing mica-plates up to half-an-inch across. 
