The Rock Cycle
When a volcano erupts lava or magma is released. When the magma goes below the earth's surface it cools slowly and intrusive igneous rocks are formed. Rhyolite is an example of an intrusive igneous rock.
When the magma cools above the earth's surface it cools very quickly and an extrusive igneous rock is formed. Granite is an example of an extrusive igneous rock.
The weathering from the wind and water causes erosion and breaks the igneous rock into sediments.
The sediment gets buried under other layers of sediment. After a long time the layers get cemented together and sedimentary rock is formed. Sandstone is an example of sedimentary rock.
Below the Earth's surface there is heat from pressure. The igneous and sedimentary rocks change from the heat and pressure. This change is called metamorphosis and forms metamorphic rock. Marble and quartz are examples of metamorphic rock.
Metamorphic rocks can turn back into sedimentary rocks through weathering and erosion or if forced deep into the earth can melt and turn into magma. Then the ROCK CYCLE starts all over again!
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