Four Ways to Make a Mountain

Mountainous regions are created by movements of the earth's crust. These movements occur very slowly, but on a large scale. Different parts of the earth's crust react in different ways to these movements, and form four basic types of mountains.

	Volcanism Outpouring lava and ash build a cone-shaped peak. The Hawaiian Islands are volcanic mountains that have "grown" out of the sea. The Cascades of the Pacific Northwest are also volcanic in origin.
Folding Pressures from within the earth sometimes fold rock layers into mountains and valleys. Ranges created in this way often resemble huge washboards. The Appalachians of the eastern United States were created by the pressure of the Atlantic Oceanplate "slamming" into the North American plate.
	Faulting Movement along breaks or faults between huge blocks of rock makes mountains that may be quite high and steep. The Himalaya lie along the line where the Indian Subcontinent meets the Eurasian landmass. The Sierra Nevada in California were formed by movements of the infamous San Andreas fault line.
Doming The core of a dome mountain was once magma, which domed up the rocks above it into a sort of blister. The Black Hills of South Dakota were formed in this manner.