Shop Windows to the Universe

Hands On Mineral Identification helps you to identify over 14,500 minerals! By M. Darby Dyar, Ph.D. See our DVD collection.
This is a drawing of a process which forms mountains on Earth.
Click on image for full size

Mountain Building by way of Subduction

Mountains are built through a general process called "deformation" of the crust of the Earth. Deformation is a fancy word which could also mean "folding". An example of this kind of folding comes from the process described below.

When two sections of the Earth's crust collide, rather than being forced down to deeper regions of the Earth, the slabs of rock can pile into each other head on, causing one or both slabs to fold up like an accordion.

This process causes the crust to be

  • 1.) raised, and
  • 2.) folded up.
In the end, a mountain range is produced.

This process is illustrated in the figure to the left. A slab of the Earth's crust, on the right is forced to go down, while the slab on the left is forced to fold up. The slab on the right might eventually melt and form a volcano.


Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Subduction

When two sections of the Earth's crust collide, one slab of lithosphere can be forced back down into the deeper regions of the Earth, as shown in this picture. The slab that is forced back into the Earth...more

Volcano Formation

Volcanoes form when hot material from below rises and leaks into the crust. The hot material, called magma, rising from lower ground, gathers in a reservoir called the magma chamber. Eventually, but not...more

Clues to Plate Movements

Many kinds of surface features are clues to a sliding lithosphere. Two types of features can form when plates move apart. At ocean ridges, the crust splits apart to make room for molten mantle rock. Continental...more

President of Peru Visits Ancient Incan Sites

The country of Peru has a new president. His name is Alejandro Toledo. Toledo really wants to help the people of Peru, but he has a really big job to do! He wants to help the poor and homeless people find...more

Grooves of Ganymede

Instead of icy-volcanism, the surface of Ganymede reveals a gradual surface stretching which is similar to the crustal stretching of the Earth. In this case, the folding and stretching of the crust of...more

Volcanic Ash

Ash is formed as a volcano erupts when rocks made by the volcano blow apart into millions of tiny pieces. The rocks are still very hot, because they just formed from lava. If the hot rocks come into contact...more

Cinder Cones

Cinder cones are simple volcanoes which have a cone shape and are not very big. Compare the size of this volcano to the strato-volcano in this image. They are usually made of piles of lava, not ash. During...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF