GEOLOGY AND SCENERY OF NORTHEAST COAST 87 
long battered by the weather of ancient days, and so long 
and successfully attacked and lowered by streams, that 
already very early in the earth’s history these mountains 
had been flattened to a relief probably as tamed as that of 
the great Canadian plateau to-day. It was this old-moun- 
tain plain, or almost-plain, which formed the nucleus of 
North America. Noone cansay as yet, even approximately, 
how much the old plateau has been affected by the destruc- 
tion of the millions of years since it was reélevated from 
beneath the sea, with its mantling load of Cambrian, 
Silurian, Devonian, and later sediments. Again and again 
the Basement has been, wholly or in part, alternately above 
and below sea-level. With each emergence it has lost sub- 
stance, and with each loss a new physical geography has 
been developed upon it. 
When a mountain-system is young, its summits are 
ranged more or less systematically in straight or slightly 
curved lines joining the crests of the various ranges. When 
the system is very old, that is, worn down flat by age-long 
wasting, these same trends may still be recognized in the 
structure of the mountain-roots. A normal range owes its 
existence, not so much to simple uplift of the earth’s crust 
as to an intense folding and crumpling together of its rock- 
strata by powerful forces acting tangentially with reference 
to the curve of the earth and transverse to the axis of the 
range. If, therefore, the Basement Complex forms the 
root of an old mountain-system, the natural inquiry arises 
as to the trend of the rock-bands now visible to the geolo- 
gist; for these, even in the absence of the long-vanished 
mountainous relief, will tell the direction of the old ranges 
and, by implication, the direction of the great compressive 
