The Alleghenian Orogeny occurred during the late Paleozoic and was the result of the collision of Africa with North America during the formation of Pangea. The collision events produced tremendous occurrences of thrust faults, folding, and metamorphism. As a result of this collision event a huge mountain belt formed that ran up the east coast of North America into Canada and Baltica, which had collided with Greenland and northern North America. Rocks were newly deformed and folded from the coast to as far as the Allegheny Plateau and the Adirondack Mountains of New York. Although the modern-day Appalachian Mountains have been heavily weathered over time, they were thought to once rival the Himalayas in size.