Earth Structure: Rock Cycle, Weathering and Erosion

• Earth structure is the study of the Earth.

Rock Cycle

• Processes that lead to a rock changing from one type to another.
• Includes: weathering and erosion, transportation and deposition, sedimentation, compaction, cementation, burial, high temperatures and pressures, melting, crystallization of magma and slow uplift to the surface.

Weathering

• The wearing down of a rock by physical, chemical, or biological processes.

Erosion

• Weathering of rock and its movement by water, ice, and wind.

Minerals

• Chemicals that a rock is made from.

Sedimentary Rocks

• Rocks formed from layers of sediment in time.
• More sediments add to layer with their own layers.
• Sedimentary rocks can contain fossils.
• Examples include: limestone, chalk, and sandstone.

Igneous Rocks

• Rocks formed from cooled magma, with the minerals arranged in crystals.
• Igneous rocks have varying sizes of crystals.
• When the magma has longer to cool, this forms rocks with larger crystals
• Examples include: granite, basalt, and obsidian.

Metamorphic Rocks

• Rocks made from existing rocks that are heated and withstand high pressure over long periods of time.
• Rocks that have changed due to changes in heat and pressure.
• When igneous or sedimentary rocks are heated or undergo high pressures, their structures change.
• Examples include: marble, slate, and schist.

Strata

• Another term for layers in a sedimentary rock.

Magma

• Molten rock.

The Layers of the Earth

• Crust is the outermost layer, it is thin and made out of sections called tectonic plates.
• Mantle is a semi liquid that causes the plates above to move due to convection currents.
• Outer core is a liquid layer made out of molten iron and other elements.
• Inner core is the inner most section, it is solid.
• Inner core is mainly made out of iron and nickel.

Igneous Rock Types

• Extrusive igneous rock type exists.
• Intrusive igneous rock type exists.