The Appalachian Mountains are approximately 480 million years old, making them the oldest mountains in North America. The Appalachian Mountains are folded mountains that were once as high as 20,000 feet. Now they reach to about 3,000 feet. How did these mountains form? A) Folded mountains occur when two plates of the Earth's crust separate. B) Folded mountains are the result of many volcanoes erupting all at the same time. C) Folded mountains form over millions of ears as sediments are deposited and build up. D) Folded mountains occur when two plates of the Earth's crust push against each other.

The Appalachian Mountains were formed after the African and the North American plates collided. Option D). Folded mountains occur when two plates of the Earth's crust push against each other.

How did the Appalachian Mountains form?

The Appalachian Mountains were formed after a collision between two continental plates, approximately 480 million years ago, during the Ordovician period.

Collision events usually occur between

Two oceanic plates.
One oceanic and one continental plate.
Two continental plates.

When two continental plates crush, they suffer boundaries modifications from which folded mountains are formed. Folded mountains get formed at convergent bundaries.

The African and North American plates collided producing this mountain formation that reached up to 20,000 feet in height. After that, they began to suffer erosion.

The correct option is D) Folded mountains occur when two plates of the Earth's crust push against each other.

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