1. Metamorphic Rocks

2. Rock Formation Sedimentary Rocks and Igneous rocks form from:
Other Rocks
Metamorphic Rocks form as existing rocks change.

3. Popcorn How do you make popcorn? Add heat to a kernal.
It pops and becomes a fluffy snack.

4. Metamorphism
The process of changing an existing rock by heat or pressure, or both.

5. Parent Rocks
The original sedimentary or igneous rock is called a parent rock.

6. Undergoing Change
Pressure can cause a rock’s minerals to flatten out in one direction.
The rock does NOT melt during this process.
If the rock did melt, what kind of rock would we now have?

7. Recrystallization Crystals form from minerals.
Heat and/or pressure break the bonds of those atoms.
The bonds then can reform in a new way.

8. Pg 97 – How rocks change

9. Changes occur over large and small areas.
Changes that occur depend on:
Type of Parent Rock
Temperature
Pressure

10. Changes occur over large and small areas.
For metamorphic change to occur over large areas there must be:
High Pressure
High Temperature
When only one of these is present, changes tend to occur over smaller areas.
Large Areas
Small Areas

11. Metamorphism Over Large Areas
Large blocks of rocks are pushing together.
Rocks are:
Buried
Pushed together
Heated
Bent
Deeper the rock, the greater the metamorphism

12. Metamorphism Over Small Areas Using Heat
Magma can push up through cracks in the rocks.
Lava can cover rocks on the earth’s surface.
Mainly due to high temperature, not pressure.

13. Metamorphism Over Small Areas Using Pressure
Rocks move and grind past each other during tectonic plate movement.
This creates a great amount of pressure.

14. Foliation Found in metamorphic rocks
Arrangement of minerals in flat or wavy parallel bands.

15. Foliated Rocks
Commonly found in rocks produced by metamorphic change over large areas.
Found in rocks that are composed of more than one mineral

16. Non-Foliated Rocks Made of mainly one type of mineral.
Different minerals cannot separate and line up.
Has not been subjected to high pressure.