Metamorphic rocks are formed from existing igneous, sedimentary, or other metamorphic rocks by heat, pressure, and chemical processes deep beneath the Earth's surface. There are two types of metamorphism: contact metamorphism near magma intrusions, and regional metamorphism caused by heat and pressure during tectonic plate movement, most commonly resulting in chemical changes to the rocks. Metamorphic rocks can be classified as either foliated or nonfoliated based on their texture.

1. Formation of Metamorphic
Rock

2. Formation of Metamorphic Rock
• Changed from one type of rock into another
by heat, pressure, and chemical processes.
• Form deep beneath the earth’s surface.
• ALL metamorphic rocks are formed from
existing igneous, sediment or metamorphic
rocks.

3. Formation
• Minerals may change in size or shape or
separate into parallel bands.
• Metamorphic formation happens two
different ways
– Contact metamorphism
– Regional metamorphism

4. Contact Metamorphism
• Formed when magma pushes through
existing rock.
• Changes the structure and mineral
composition of surrounding rock.

5. Regional Metamorphism
• Metamorphism sometimes occurs with
tectonic plate movement.
• Tremendous heat and pressure is created
at plates edge.
• This heat and pressure will cause
chemical changes in the rocks.
• Most metamorphic rock
is created be regional
metamorphism.

6. Classification of Rocks
• Rocks can be classified into two different
types based on their texture:
– Foliated
– Nonfoliated