Metamorphic Rocks

Metamorphic rocks have been changed from a pre-existing rock.Caused by extreme heat and/or pressure.

Regional Metamorphism

Caused by extreme pressure and heat.Happens over wide “regions”.

Contact Metamorphism

Caused by contact with extreme heat.

Meta. rocks will often have foliation or a distorted structure.

Distorted Structure

Foliation is a “grain” to the rock.

Types of Foliation:

Gneissic Foliation- minerals are squished into bands.

“Zebra Stripes”

Bands Layers

Banding vs. Layers

Schistose foliation- minerals have been squashed into flakes of mica.

Slaty foliation- Rock splits into flat, thin layers.

Take out your Handy Dandy Earth Science Reference Tables Page 7.

Slate

Phyllite

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=

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Phyllite

Schist

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=

+

Schist

Gneiss

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=

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