1. Metamorphic rocks can be classified into one of three sub-families:
Foliated -
A banded rock splitting more or less evenly into layers, usually results from the combination of both heat and pressure (gneiss).
Unfoliated -
A rock with no definite layers or bands, splits randomly, primarily due to heat effects (marble).
Deformed -
Parent rock is stretched and deformed but relatively identifiable (metaconglomerate - stretched pebble).

2. Metamorphic Grade

3. Look at your own metamorphic rocks while viewing the following slides
Look at your own metamorphic rocks while viewing the following slides. You should have a sense of metamorphic rocks before completing the identification activity

4. Foliated Rocks - Slate and Phyllite
Black slate
Red slate
Phyllite - light
Phyllite - dark

5. Foliated Rocks - Schist and Gneiss
Mica Schist
1 cm
Gneiss
Gneiss close up showing mineral layers

6. Unfoliated Rocks - Marble
Right - Pure white marble; Northern Italy.
Below - Banded marbles;
the bands are from the original
deposits and/or different minerals.

7. Unfoliated Rocks - Quartzite
Quartzite is hard and breaks across the grains whereas sandstone breaks between the grains.
Why does this difference exist?
What does our sample of quartzite look like?

8. Deformed Rocks - Stretched Pebble Conglomerate (metaconglomerate)
The pale coloured quartzite pebbles have been visibly stretched
but are still quite identifiable.

9. The Rock Cycle

10. West Coast Rocking - The Rock Cycle in Action
C & T p. 21

11. The End