Metamorphic Rocks

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Metamorphic Rocks
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Rock cycle
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General Features

• metamorphic means change in shape
• metamorphic rocks can come from any other kind of
  rock (called the parent rock)
• rocks are changed (undergo metamorphosis) due to
  heat and pressure

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Texture for Metamorphic Rocksis Alignment and
Size of Crystals

• foliated texture parallel alignment
• foliated texture flat or wavy bands or stripes

• non-foliated texture not pressed into sheets
• also called massive

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Foliated Rock Classification

• Foliated Classified
• 1. Nature of foliation
• 2. Size of Crystals
• 3. Degree to which minerals segregated into
  light and dark bands

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Rock Cycle
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Types of Metamorphism

• Contact metamorphism
• High heat, low pressure

• Parent rock came into contact with a heat source
• How could the parent rock be heated up?
• What types of formations could provide this heat
  source?

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Types of Metamorphism ctd.

• Regional Metamorphism
• High pressure, high heat

Gneiss "nice"
Schist

• Parent rock changes over a widespread area
• Where could the rock change over a widespread
  (area that is as large as a state or even several
  countries) area?

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Types of Metamorphism ctd.
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Summary Questions

• What are heat and pressure changing?
• What can texture tell you about a metamorphic
  rock?