96 



LABRADOR 



to be applied, the minerals of the existing rock should 

 show the crushing and granulation due to the strain of 

 the later mountain-building. Such has been the fate of 

 great masses of this gabbro in other parts of Labrador 

 and in Quebec, but, so far as known, the coast gabbros 

 have escaped extensive crushing. 



The same remark applies to a quite different class of 

 intrusive rocks which leap to the eye of every observer on 

 the coast. Toward the close of the epoch -of mountain- 

 growth in the Basement Complex, perhaps at or near the 

 date of the great gabbro intrusion, the base of the entire 

 range from Belle Isle to Chidley was fissured and^ in a 

 sense, shattered. To that event there contributed the 

 irregular contraction of the granites and highly heated 

 schists as they cooled, and doubtless, also, a general settling 

 down of the ridged-up crust after the earth's paroxysm 

 was over. Countless cracks and fissures were thus formed 

 far down below the lofty, rugged surface of the range. The 

 fissures were seldom, if ever, left gaping. So soon as formed 

 and in the very act of forming, they were filled with highly 

 molten basaltic rock which then froze or crystallized. 

 Thus the range was strongly knitted together again. So 

 firm was the new cementation of the shattered formations 

 that the rocks filling the ancient fissures now form so many 

 ribs strengthening the mountain-chain against the attack 

 of the weather. All up and down the coast the gray sea- 

 cliffs and mountain-slopes are seamed with these thousands 

 of basaltic fissure-fillings, the so-called " dikes" of "trap." 

 Wonderfully fine examples occur on the north side of the 

 entrance to .Hamilton Inlet. From the anchorage in Ice 

 Tickle one should mount any one of the higher hills on either 



