Formation of Metamorphic Rock

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.

Formation

• Minerals may change in size or shape or separate into parallel bands.

• Metamorphic formation happens two different ways–Contact metamorphism–Regional metamorphism

Contact Metamorphism

• Formed when magma pushes through existing rock.

• Changes the structure and mineral composition of surrounding rock.

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.

Classification of Rocks

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