1. Metamorphic rocks Today’s Chapter 8: Lecture
Classification metamorphic rocks
Texture & Composition
2) Contact metamorphism
3) Metamorphism along faults
4) Regional metamorphism
5) Metamorphism & plate tectonics

2. Agents of metamorphism
Heat
Pressure (stress)
Chemical activity (fluids)
Metamorphic environments
Contact
Cataclastic
Regional

3. Common metamorphic rocks
gneiss
slate
mica schist
marble
quartzite

4. Common metamorphic rocks
Foliated rocks

5. Common metamorphic rocks
Foliated rocks
slate
Slate

6. Fig. 8.13
W. W. Norton

7. Fig. 8.10
W. W. Norton

8. Fig. 8.09
W. W. Norton

9. Slate Very fine-grained, Platy minerals (Clays, Micas) Foliated rocks
Common metamorphic rocks
Foliated rocks
slate
Slate
Very fine-grained,
Platy minerals
(Clays, Micas)
COLORS: CONTAINS:
black slate organic material
red slate iron oxide
green slate chlorite

10. Slate TILTING Foliated rocks Original shale Original shale
Common metamorphic rocks
Foliated rocks
slate
Original shale
Slate
TILTING
Original shale
Rock cleavage

11. Slate Foliated rocks Original shale Bedding planes
Common metamorphic rocks
Foliated rocks
slate
Slate
Original shale
Bedding
planes
Rock cleavage

12. Slate Foliated rocks Foliated rocks Original sedimentary layering
Common metamorphic rocks
Foliated rocks
slate
Foliated rocks
1) Common metamorphic rocks
Slate
Original
sedimentary
layering

13. Fig. 8.12a
W. W. Norton

15. Veins developed
in slate

16. Phyllite Platy minerals(e.g. muscovite or chlorite Foliated rocks
Common metamorphic rocks
phyllite
Phyllite
Fine- to medium-grained
Platy minerals(e.g.
muscovite or chlorite
Phyllite
Slate

17. Foliated rocks
Common metamorphic rocks
phyllite
Phyllite

18. Biotite Mica

19. Phyllite Foliated rocks Original sedimentary layers
Common metamorphic rocks
phyllite
Original
sedimentary
layers
Phyllite

20. Schist Strongly foliated Easy to split in slabs Foliated rocks
1) Common metamorphic rocks
schist
Schist
Coarser-grained
Strongly foliated
Easy to split in
slabs
Pioneer Range, Idaho

21. Composition plus texture
Foliated rocks
Common metamorphic rocks
schist
Mica Schist
Rock name:
Composition plus texture

22. Schist Foliated rocks Segregation of minerals into bands Quartz Micas
Common metamorphic rocks
schist
Schist
Segregation
of minerals
into bands
Quartz
Micas

23. Schist
Quartz
Mica

24. Schist Foliated rocks Segregation of minerals into bands Begins.
Common metamorphic rocks
schist
Schist
Segregation
of minerals
into bands
Begins.

25. Schist Appearance of new minerals Foliated rocks Foliated Rocks
Common metamorphic rocks
Foliated Rocks
schist
Appearance
of new minerals
Schist
Amphibole