Rock Cycle

There are three major types of rocks

• Igneous

• Sedimentary

• Metamorphic

Igneous rocks

• Igneous rocks are formed when molten rock (magma) from within Earth cools and

solidifies. • There are two types:

• intrusive igneous rocks solidify beneath Earth's surface;

• extrusive igneous rocks solidify at the surface.

• Examples: Granite, basalt, obsidian

Volcanoes’ lava or magma forms new igneous rocks

Sedimentary rocks

• Sedimentary rocks are formed when sediment (bits of rock plus material such as shells and sand) gets packed together

by cementation and compaction. • They can take millions of years to form.

• Most rocks that you see on the ground are sedimentary.

• Examples: Limestone, sandstone, shale

SedimentaryThe sand at the beach is made of little pieces of rock that broke off larger rocks. These little broken pieces are called sediment. There are many types of sediment including sand, mud, pebbles, and even dust. It takes a very long time, thousands and thousands of years, but sediments can form a rock if they become stuck together.(cementation & compacted)

Metamorphic rocks

• Metamorphic rocks are sedimentary or igneous rocks that have been transformed by heat, and pressure (or both).

• Metamorphic rocks are usually formed deep within Earth, during a process such as mountain building.

• Examples: Schist, marble, slate

Metamorphic Rock

Heat and pressure change the previous sedimentary rock into a metamorphic rock.

The Rock Cycle:• The rock cycle explains how the different types of

rock form. • The three types of rock at Earth’s mantle melt into

magma. • Magma that cools and hardens underground forms

intrusive igneous rock. • Weathering breaks the rock into sediment. Erosion

causes the sediment to move to other locations. These sediment are glues together by cementation.

• Pressure squeezes and compacts the sediment together, forming sedimentary rock.

• Heat and pressure change igneous and sedimentary rock into metamorphic rock

Rocks can change into other rocks! The stuff that rocks are made from stays the same, but the rocks do not. Over time rocks are recycled into new rocks. Moving parts of Earth's surface layer help rocks recycle!