2. Rock Letter DescriptionRock NameFoliation?Protolith?

3. Read pp. 145-148  Mr. Parker's Group Reading Strategy:  One person reads out loud, two read along silently  Everyone thinks about it for 30 seconds silently (keep time!)  Silent reader sumarizes with a complete sentence  Everybody writes a complete sentence in notebook  Move on to the next paragraph, switch jobs  Share out to the whole class

5. All Metamorphic Rock starts off as Igneous or Sedimentary Rock  Geologists are always interested in what kind of rock a metamorphic rock used to be.  The rock from which a metamorphic rock is formed is called a protolith.

6. Heat and Pressure  Deeper = HOTTER because you are closer to the core.  Deeper = more PRESSURE because there is more rock above you.

7. Heat and Pressure  Heat makes rock more MALLEABLE (more bendy)  Pressure DEFORMS rock by compacting it, stretching it, or twisting it.  Together HEAT and PRESSURE change the composition of the old rock

8. Foliation  Foliation occurs when a rock is squeezed by extreme pressure to form bands and layers  However, foliation does not always happen. There are both foliated and non- foliated metamorphic rocks

10. Two types of Metamorphism Regional  When metamorphism happens to an extensive (big) REGION of rock  This can happen when two plates collide, or when rock is pushed deep underground

11. Two types of Metamorphism Contact  Contact Metamorphism happens when rock comes in CONTACT with hot magma (but does not melt itself).

12. Where are metamorphic rocks found?  However, because metamorphosis is caused by extreme HEAT and PRESSURE, metamorphic rocks are usually found where something extreme has happened (like volcanic activity or two plates colliding)

13. Some examples… Before: GraniteAfter: Gneiss

14. Some examples… Before: ShaleAfter: Slate

15. Some examples… Before: LimestoneAfter: Marble

16. Metamorphic Rock…  Is created out of old rock by heat and pressure  Doesn’t melt (or else it would be igneous rock)  Is often foliated/deformed by extreme pressure  Formed by regional or contact metamorphism

17. Vocabulary  Foliation: the tendency for a metamorphic rock to split along parallel lines  Deformation: the process of rocks changing shape due to extreme heat and pressure  Regional metamorphism: The type of deformation that occurs to a large area when land masses collide  Contact metamorphism: The type of deformation that occurs when rock comes in contact with magma but does not melt