Geoscience Reference
In-Depth Information
Killdevil Mountain, Newfoundland, is part of the Appalachian mountain chain thrust up when continental plates col-
lided 400 million years ago.
The continental plates have come together a number of times to form so-called supercontinents since at least
2.6 billion years ago, when a supercontinent formed the nucleus of the North American continent centered, on
the Canadian Shield. Then, about 2 to 1.8 billion years ago, seven microcontinents collided with a larger con-
tinent along a strip that extended from southern California to southern Sweden. Each of these events was ac-
companied by mountain building and the subsequent erosion and wearing down of these mountain ranges. But
