GEOLOGY AND SCENERY OF NORTHEAST COAST 121 
basin produced by the glacial plucking away of many 
blocks of the fresh rock (gneiss) frozen into the ice, and so 
lifted and freighted off by the moving glacier. In the face 
of the low cliff can be discerned the planes of rifting and 
the outlines of several blocks that were in the very act of 
being plucked away as the ice disappeared from the country. 
It is an instructive case of natural quarrying. Ten thou- 
sand other examples on the coast would show quite as 
clearly that a glacier works with crowbar and crane as 
well as with gouge and chisel. Using all its powers, the 
ice-cap strongly modified the details of relief on the plateau 
of southern Labrador. 
In so reaching a principal conclusion from the glacial 
studies, let it not be forgotten that normal stream-cutting 
in pre-Glacial times produced the grand features of the 
sculpture. 
The energy of glacial attack is manifested not alone in the 
remodelling of plateau and valley ; its power leaves enduring 
records on the single ledge of rock. Observations on the 
living glaciers of the world show that they scour their beds 
not so much by the direct friction of ice against ledge as 
by the dragging of frozen-in boulders over the bed-rock. 
The pressure so applied is truly enormous. Deep grooves 
or shallower ‘“‘strie”’ running in the direction of ice-flow 
are cut in the solid rock by such “graving-tools.” Lime- 
stone, slate, trap, granite, or schist may be thus marked by 
scratches, furrows, or channels from a fraction of an inch to 
a foot or more in depth. They are not continuous mark- 
ings, but occur only where the wearing boulder has been 
pressed with irresistible might against the bare rock. 
Shallow and deep striations of the sort are to be found on 
