Rocks and the Rock Cycle

What is a rock? The material that makes up the solid parts of the Earth is known as rock. It may be made of one or more minerals It can be solid organic matter.

Major Types of Rocks Igneous Sedimentary Metamorphic

Igneous Rock Igneous mean “from fire” Forms when magma cools and hardens Lava is magma exposed to Earth’s surface Pumice Granite Obsidian

Metamorphic Rock Metamorphic means “changed form” Metamorphic rocks are existing rocks that have been changed Can be changed by extreme pressure, temperature, or chemical processes Marble Slate Quartzite

Sedimentary Rock Weathering (wind, waves) can break rock down into small pieces Pieces are called sediment Sediment can be deposited (erosion) and compressed together to form sedimentary rocks Coal Iron Ore Limestone

What is weathering? Weathering breaks rock down into pieces… Erosion moves the sediment to a new location Weathering can be mechanical (physical) or chemical

Mechanical Weathering… Breaks rocks down into smaller pieces. It is still the same type of rock, just smaller. Wind, water, and ice can all do this… think of how ice cracks the sidewalk in the winter. Arch Rock, Mackinaw Island, MI

Chemical Weathering… Breaks down rock by chemically adding or removing chemical elements. It is no longer the same type of rock; it is a different rock.

What is Erosion? When a rock weathers, the particles may be carried away to a new location. The process of transporting the sediment is called erosion. Wind, water, and ice can all cause erosion.

What is Erosion?

The Rock Cycle Any of the three rock types can be changed into another type Geologic processes and forces cause these changes

The Rock Cycle

Assignment Create flashcards for the following terms: Igneous rock Metamorphic rock Sedimentary rock Melting Crystallization Erosion Deposition Cementation