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The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.
This is a drawing of a process which forms mountains on Earth.
Click on image for full size

Mountain Building

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 lithosphere collide, rather than being subducted, where one slab of lithosphere is forced down to deeper regions of the Earth, the slabs pile into each other, causing one or both slabs can fold up like an accordion. This process elevates the crust, folds and deforms it heavily, and produces a mountain range. Mountain building and mantle subduction usually go together.

This process is illustrated in the figure to the left. The lithospheric slab on the right is subducted, while the force of the collision gradually causes the slab on the left to fold deeply. Along the way, melting of the subducted slab leads to volcano formation.

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