Metamorphic rock

Quartzite, a form of metamorphic quartz.

Folded strata in a metamorphic rock from near [Geirangerfjord], Norway

A metamorphic rock is a type of rock which has been changed by extreme heat and pressure. Its name is derived from the word morph, meaning change.

There is always more pressure and higher temperature under the Earth's surface. In the root of a mountain chain or near a volcano these forces will be enough to change shape of the strata and the minerals it is made of. Sedimentary rock which has been near such forces often looks as if a giant had twisted it and heated it over a fire. Examples of metamorphic rock:

• Marble a metamorphic rock formed from limestone.
• Slate is a metamorphic mudstone or shale.
• Quartzite is metamorphic sandstone.

The recrystallisation of minerals after heating generally causes the destruction of any fossils the rocks might have contained.

Other pages

• List of rocks
• Igneous rock
• Sedimentary rock
• List of minerals

Other websites

• Metamorphic textures - Middle East Technical University
• Metamorphism - U. of Alabama
• Types of metamorphism - Tulane U.
• Contact metamorphism example