Rocks

Igneous RockOrigin: Magma from within the

Earth cools to form igneous rock.Extrusive: Magma that reaches the

surface, becomes lava and cools quickly.

Typically this type of igneous rock is basalt, a rock with very small crystals

Intrusive: Magma that cools slowly within the earth.

Typically this type of igneous rock is granite, a rock with larger crystals.

Sedimentary RockOrigin: • Pieces of eroded and weathered rock, of various sizes

and called sediments, are carried by water and deposited in the oceans, seas or lakes.

• Once deposited, the pieces are buried by more sediment. Over millions of years, these sediments are compacted and cemented together to form rock.

• Eventually these sedimentary rocks are exposed by erosion and weathering and/or uplift from plate tectonics.

Metamorphic Rock• Origin: When igneous or sedimentary

rock comes into contact with heat, and in some cases certain chemicals, it changes, or “morphs” into different rock called metamorphic rock.