1. Metamorphic Rocks
Change is Good

2. Metamorphic Rocks
Formed from intense heat and pressure!

3. Sources of Heat
degree Celsius temperatures are needed for Metamorphism.
Sources of heat include:
Magma or lava
Friction from faulting

4. Sources of Pressure Mountain building (plate movements)
Intrusions of magma into surrounding rocks
Weight of overlying layers (1-5 miles thick)

5. Types of Metamorphism
1. Contact - (local) due to heat and pressure of magma intrusions or faulting.
2. Regional - due to mountain building (affects a wide area)

6. Types of Metamorphic Rocks
2-Types: Foliated and Nonfoliated
Foliated – Minerals are aligned into parallel layers. Often looks like banding of dark and light minerals (sort of like a zebra). Results from pressure in two directions.
Nonfoliated - (recrystallized) from thermal metamorphism (intense heat); the enlargement or the formation of new minerals; large inter-locking crystals with a shiny appearance.

7. Texture of Metamorphic Rocks
Foliated or Nonfoliated
Nonfoliated usually look chrystalline (marble, quartzite)
Grain Size: (Fine, Medium, Coarse)

8. Foliated Rocks
Slate
Phyllite
Schist
Gneiss

9. Foliation: How it happens!

10. Nonfoliated Rocks
Marble
Quartzite
Anthracite coal
Hornfels
Greenstone

11. Parent Rocks Metamorphic Rock Parent Rock Slate Phyllite Schist Gneiss
Greenstone
Marble
Quartzite
Anthracite Coal
Hornfels
Shale or Mudstone
Slate
Granite or Diorite
Basalt
Limestone
Sandstone (with quartz)
Bituminous Coal
Anything

12. Tectonic Boundaries for Metamorphic Rocks
Continent-Continent Convergent Boundary.
Example: India and Asia forming the Himalayas.
Regional Metamorphism

13. Transform Boundary (Strike-Slip Fault)
Two plates slide past each other
Example: San Andreas fault in California.
Contact/Regional Metamorphism.

14. Contact Metamorphism from magma
Magma intrusions cause metamorphism.
Contact metamorphism is caused by dikes and sills.
Regional metamorphism is caused by laccoliths and batholiths, which are large chambers of magma.
The intense heat can metamorphose the surrounding and intruded rock layers.