Different Types of Rocks and the Rock Cycle

Igneous Rocks • Formed from liquid magma or lava that cools and solidifies either after eruption onto the surface or deep underground.

Igneous Rocks • Crystal size of rock depends on how fast it cooled.

• Erupted from a volcano – Cooled very fast human eye can’t see crystals

Igneous Rocks • Crystal size of rock depends on how fast it cooled.

• In a magma chamber underground – Cooled slowly human eye can see crystals

Sedimentary Rocks • Formed either as fragments of mineral/fossils that are cemented together or as minerals that are precipitated out of water.

Sedimentary Rocks• Grain size of rocks depends on

how fast the water was moving.• If water is moving fast, then it

carries smaller grains downstream and deposits larger grains.

Sedimentary Rocks• Grain size of rocks depends on

how fast the water was moving.

• If water is moving slowly, then it deposits the smaller grains.

Sedimentary Rocks • In oceans, critters create shells, skeletons, and cell walls that, when deposited, form various types of limestone.

Metamorphic Rocks • Formed when pre-existing rocks are changed into new rocks because of an increase in temperature or pressure as the rocks are buried.

Metamorphic Rocks • At very high T & P (deep within the Earth), the rocks become color banded. These rocks were formed deep beneath a mountain.

The Rock Cycle