1. How are Metamorphic Rocks Classified?
Today’s Objective:
How are Metamorphic Rocks Classified?

2. Metamorphism – “to change form”
Formation of Metamorphic Rocks
- Most changes occur at high temperatures and pressures a few km below the Earth’s surface.
Gneiss Rock

3. What causes metamorphism?
Heat – Provides the energy needed to drive chemical reactions.
- The heat comes from magma and the change in temperature as you enter into the earth
Pressure (Stress) – Causes a more compact rock with greater density

4. ESRT pg 7 – Bottom

5. Important Vocab! Contact Metamorphism – Hot magma moves into rock
making contact with existing rock.
Regional Metamorphism –
Large amounts of pressure
results in large-scale deformation
and high-grade metamorphism.
(these rocks are very dense)
Important Vocab!

6. Types of Regional Metamorphism
Pressure from being squished by other sediments
Pressure from plate movement (mountain building)

7. Texture of Metamorphic Rocks
Foliated Metamorphic Rocks - rock
has a layered or banded appearance.
Ex: Gneiss & Schist.
Important Vocab!

8. Banded vs. Mineral Alignment
Crystals appear squished together
Notice the LIGHT dark LIGHT dark layers

9. Marble - A Nonfoliated Metamorphic Rock
Important Vocab!
Nonfoliated Metamorphic Rocks –
- Does not have a banded texture.
- Most only contain one mineral.
Marble - A Nonfoliated Metamorphic Rock

10. Parent Rock … What a rock begins as
For Foliated Metamorphic rocks as heat and pressure are added you start with shale then it becomes slate then phyllite then schist then gneiss.

11. Parent Rock … What a rock begins as
For Nonfoliated Metamorphic rocks as heat and pressure is added, you must look to the COMMENTS column for the parent rock.

12. Regional Metamorphism
Using your knowledge of earth science, your earth science reference tables and your class notes to compare and contrast contact and regional metamorphism in your notebook.
Regional Metamorphism
Contact Metamorphism
Compare
Contrast