Metamorphic Rocks

Metamorphic rocks are formed by heat and pressure.

As the metamorphic rock is buried more deeply, temperatures and pressures continue to rise.

If the temperature becomes hot enough, a metamorphic rock will melt If the temperature becomes hot enough, a metamorphic rock will melt. The molten rock is called magma.

Large amounts of metamorphic rocks are usually found underneath large mountain chains.

A magma intrusion will heat up the surrounding rocks and form new metamorphic rocks.

Small amounts of metamorphic rocks are usually found near magma intrusions.

If the sedimentary rock is buried deep in the crust under more and more sediment, often due to plate tectonic movements, the heat and pressure causes metamorphism to occur. This transforms the sedimentary rock into a metamorphic rock

Igneous rocks can undergo metamorphism (as a result of heat and pressure) to form metamorphic rocks. Sedimentary rocks can do the same.

Metamorphic Rocks

Heat and Pressure Original rock is called the parent rock New rock is resulting rock (metamorphic rock) Parent Rock New Uses in real life Limestone Marble Kitchen counters Shale Schist pencils

Changes that can occur during metamorphism Pressure causes a rock’s minerals to flatten out in one direction Rock always remains solid; doesn’t melt If the temp gets high enough to melt the rock, it changes to an igneous rock

Changes over large areas Most metamorphic changes occur over large areas (deep and wide) where the temperature and pressure are high The deeper below the surface, the greater the metamorphic changes occur Example: Large blocks of rock press together and push up mountain ranges