1. Metamorphic Rocks
Heat and/or Pressure

2. Metamorphic rocks Metamorphic rocks are formed by: There are 2 types:
Heat
Pressure
Chemical action
There are 2 types:
Foliated—”stripes”
Non-foliated—”no stripes”

3. Metamorphic
Rocks formed from other rocks due to exposure to high temperatures and pressures
Change the texture, mineralogy or chemical composition
WITHOUT MELTING

4. Formation of Metamorphic Rocks
Heat and pressure
Shale to Slate (F)
Limestone to Marble (N)
Sandstone to Quartzite (N)
Granite to Gneiss (F)
Appearance, crystal structure, texture, and mineral content can change.

7. Classification of Metamorphic Rocks
Foliated – grains arranged in parallel layers or bands
Slaty – can’t see any grains
Phyllitic – larger, but still to small to see (doesn’t look as smooth)
Schistose – visible grains, breaks in layers
Gneissic banding – striped…
Non-foliated – grains arranged randomly

8. Slaty
Phyllitic
Schistose
Gneissic
Non-folliated

9. Foliations

10. Uniform Pressure

11. Directional Pressure

12. Unfoliated Rocks

14. Phylite – Small crystals

15. Schist – bigger crystals

16. Marble

17. Foliated Rocks

18. Gneiss

19. Slate

20. Slate