How a little bit of heat & pressure transform rocks! Metamorphic Rocks How a little bit of heat & pressure transform rocks!

Metamorphic Rocks The term "metamorphic" means "to change form." The mineral composition of the rock must change for the rock to become metamorphic. Gneiss on top Slate on bottom

1) What is a metamorphic rock? Rocks buried deep in the Earth at high temperatures and pressures form new minerals and textures all without melting.

2) What types of rocks can undergo metamorphism? Any rock (igneous, sedimentary, or metamorphic) can become a metamorphic rock.

Other rocks are exposed to high heat & pressure To change form

3) Where do rocks become metamorphic? Deep within the Earth.

4) What is contact metamorphism? When a rock comes in contact with a heat source, such as a magma pool. The hot magma changes a narrow section of the surrounding rock. Hornfels

Click on link and scroll down for nice pictures of metamorphic rocks.

5) What is regional metamorphism? Occurs in areas with higher heat and pressure. Larger areas are affected. Usually occurs as a result of the Earth’s plates colliding or moving.

6) What are the two textures of metamorphic rock? Classified according to its composition and texture. Foliated Nonfoliated.

Foliated Non-Foliated Other rocks are exposed to high heat & pressure To change form Other rocks are exposed to high heat & pressure Foliated Non-Foliated

7) What are foliated metamorphic rocks? Minerals have been flattened and pushed down into parallel layers. The bands in foliated metamorphic rock look like pages in a book. Slate Gneiss

Flattened & pushed into parallel layers To change form Other rocks are exposed to high heat & pressure Foliated Non-Foliated Flattened & pushed into parallel layers slate gneiss Phyllite

8) What are non-foliated metamorphic rocks? Do not display layers. Massive structures with no obvious banding. Mineral grains grow and rearrange, but they don’t form layers. Quartzite Marble

Flattened & pushed into parallel layers To change form Other rocks are exposed to high heat & pressure Foliated Non-Foliated layers Anthracite coal Flattened & pushed into parallel layers Quartzite slate gneiss marble phyllite