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