1. Metamorphic Rocks

2. Formation of Metamorphic rocks
Metamorphism means “to change form.”
Most metamorphic changes occur at elevated temperatures and pressures.
Conditions for formation are found a few kilometers below the Earth’s surface and extend into the upper mantle.

3. 3 Ways Metamorphism Takes Place
Contact
Regional
Dynamic

4. Contact metamorphism occurs when magma moves into rock.
Occurs near a body of magma
Changes are driven by a rise in temperature

5. Regional metamorphism results in large-scale deformation and high-grade metamorphism
Directed pressures and high temperatures occur during mountain building.
Produces the greatest volume of metamorphic rock

6. Dynamic Metamorphism is associated with fault lines (where earthquakes happen)
high-pressure/low-temperature metamorphism

7. 3 agents of metamorphism
Heat
Pressure
Fluids (Hydrothermal Solutions)

8. Agents of Metamorphism
Heat
Provides the energy needed to drive chemical reactions
Pressure
Causes a more compact rock with greater density

9. Agents of metamorphism
Fluids (Hydrothermal Solutions)
Hot water-based solutions escaping from the mass of magma
Promote recrystallization by dissolving original minerals and then depositing new ones

10. Classification of Metamorphic Rocks
Foliated: rocks with mineral crystals arranged in cable-like distorted layers/structures
Mineral Alignment
Banding
Animation: Foliation

11. Non-foliated: rocks with recrystallized minerals; no layering
Recrystallization: This is the growth of new mineral crystals from other rocks.