106 LABRADOR 
deep NE.-SW. valley. On the southeast the valley is 
bounded by a similar arrangement of cliffs and taluses. 
It ends as a great cul-de-sac, two miles in length, in a thou- 
sand-foot head-wall over which there cascades a large 
brook. 
“On landing, I found that the first and natural impres- 
sion, that this systematic array of scarps and taluses sig- 
nified a stratified structure for the massif, was justified.” 
At the foot of the great cliff the light-colored gneisses 
and other crystalline schists of the Basement form broad 
ledges well scoured by the ice of the Glacial Period. Their 
gently rolling surface is considerably more uneven than the 
old “fossil” land-surface on these same crumpled, gnarled, 
and twisted rocks. The overlying, veneering strata of the 
plateaus include black slates, quartzites, and sandstones, 
apparently all sea-bottom deposits ; but probably more than 
1500 feet of the half-mile of thickness in these bedded rocks 
belongs to a volcanic formation. For unknown centuries 
this part of the Labrador must have been the home of one 
or more, perhaps many, volcanoes of large size. Millions 
of years ago they erupted enormous volumes of ‘“‘ash”’ and 
other débris of lava. Most of the lava was shattered into 
angular fragments, coarse and fine, by the violence of ex- 
plosion. In the resulting deposits one can find abundant 
and very perfect ‘“‘bombs” with the rounded shapes and 
cracked surfaces of lava masses freezing as they spun through 
the air from the mouth of Nature’s cannon. Other thick 
sheets of solid lava represent the quiet flows that signify 
yet greater power in the eruptive force. 
So far only the most cursory examination has been given 
this important rock-section. No organic fossils have been 
