The Rock Cycle

Anywhere on Earth…  You may observe processes (such as earthquakes and volcanoes ) changing Earth’s landforms because of processes inside the Earth.

What are Earth’s landforms made of?

Landforms (in general) are made primarily of rock.  Rocks are non-living substances made up of minerals.  Rocks are found on the surface and deep in the Earth as molten magma.  Rock is brought up by volcanoes.

Do rocks stay the same?  Rocks may be broken into pieces over time by…  Wind  Water  Ice  Living Things  Chemicals  This is called…

Weathering

Do rocks stay still?  Weathered rock can be broken into pieces called sediment.  When nature moves rock from one place to another, it is called…

Erosion

Not all rocks are the same…  …Do you know what different types of rock there are?  Rocks are classified based on how they are formed.  There are 3 basic types of rock.

Igneous Rock  Formed when hot magma or lava cools and hardens above or below the surface.  “igneous” means “made from fire”

Igneous Rock  Obsidian is a well- known type of igneous rock.

Sedimentary Rock  Formed when sediment (including plant and animal material) builds up over time.  Form layers that give clues about Earth’s past.

Sedimentary Rock  Sandstone is a well-known type of sedimentary rock.  Fossils are often found in sedimentary rock layers.

Metamorphic Rock  Formed when extreme heat and pressure change rocks.  Occurs under the surface of the Earth.

Metamorphic Rock  Marble is a well- known form of metamorphic rock.

Rocks change slowly over time…  …into other types of rock!  This is called…

The Rock Cycle

Think… …What can rocks tell us about Earth’s past or Earth’s future? …How are rocks important for humans? Do we use them? …What are the building blocks of rocks?