Page 34 - Curriculum Visions Dynamic Book

 When deeply buried rocks are squashed together, such as at subduction zones, they can be folded without breaking. Later, when
they are brought to the surface as mountains and then eroded, the pattern of folds is clear to see. This is part of the Zagros Mountains of Iran, showing unroofed Anticlines.
 A cross section through the Alps of Europe gives some idea of the way that the movement of plates crushes rocks into great mountain ranges.
anticline An arching fold of rock layers where the rocks slope down from the crest.
asthenosphere The region below the lithosphere, and therefore part of the upper mantle, in which some material may be molten.
moUntain range A long, narrow region of very high land that contains several or many mountains.
sediment Any particles of material that settle out, usually in layers, from a moving fluid such as air or water.
space shUttle NASA’s reusable space vehicle that is launched like a rocket but returns like a glider.
The partially molten layer below the crust is the upper mantle. Scientists call it the asthenosphere.
At subduction zones deep trenches develop, which
are continually filled with sand, clay, and other materials (sediment) washed in after erosion of the land. This material is not as dense as the rocks of the mantle and so tends to float on the mantle. As it is squashed at the subduction zone, it sometimes refuses to sink back into the mantle. When this occurs, the material remains on the surface, but occupies a narrower and narrower zone. The only way for this to happen is for the material of the zones to buckle up. Buckled up and folded rocks of this kind make moUntain ranges.
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