What Is Earth's Crust Like?
ES0801  Mountains
The formation of folded mountains on Earth's surface can be compared to the process of wrinkling a flexible rug on a floor. As horizontal pressure is applied along the edge of a rug, folds appear perpendicular to the direction of pressure. On Earth, as horizontal pressure is applied to rocks, ridges and valleys form perpendicular to the direction of the pressure.

This image shows a view of the Himalayan Mountain belt in Pakistan, as viewed from an orbiting space shuttle. The entire field of view shows parallel ridges and valleys of folded mountains.

4. In what direction was pressure applied to create the Himalayan Mountains?

Consider the "wrinkled rug" model again. Would you be able to wrinkle a rug if it were attached securely to the floor? What does this observation suggest about Earth's crust and interior?

 Step:   1   2   3   4   5