92 LABRADOR 



before geologists to-day. It has been proved in certain fa- 

 vourable localities that such schists are the result of the alter- 

 ation of more ancient slates, sandstones, conglomerates, vol- 

 canic ash, and lava-flows, under the same conditions as once 

 obtained within the Archean range of northeastern Labra- 

 dor. Here again is a wide field open to further exploration. 

 The geologist who seriously studies these coastal rocks of 

 Labrador, wonderfully exposed as they are, may some day 

 establish new principles of interpretation, or confirm those 

 now forming the basis of modern earth-science. 



During the paroxysmal though extremely slow growth 

 of a lofty, alpine mountain-range, other changes of great 

 moment occur in the deep, highly heated core of the range. 

 The foundations of the huge pile are unloosed, and enormous 

 blocks of the solid rocks are displaced by molten or 

 thoroughly plastic matter, thrust up into the range by 

 titanic subterranean force. There cooling, this material 

 crystallizes into solid rocks of the granite type. As it 

 crystallizes, the whole mass may be pulled out in the 

 wrenching shear of mountain-building, much as soft pitch 

 may be drawn out in the hands. In such a case the min- 

 erals composing the new rock are arranged in lines, and not 

 in planes, as in ordinary schists. An unusually fine example 

 is exhibited on a large scale at Pottle's Cove, West Bay, 

 halfway between Belle Isle and Hamilton Inlet. The 

 rock is there a common light pinkish gray granite possessing 

 this curious arrangement of its constituents a witness 

 to the " storm and stress" period of Archean mountain 

 growth. 



Late in the mountain-building period there occurred one 

 of the most important underground events yet chronicled 



