1. Rocks Rock!!!: Igneous, Metamorphic, and Sedimentary

2. I. Igneous Rocks
A. Forms when magma cools and hardens

5. Igneous (cont.)
A. 2 Types
1. Intrusive igneous rock: magma cools deep below crust
Extrusive igneous rock: magma/lava cools on the surface

6. Intrusive Igneous Rocks

7. Extrusive Igneous Rocks

8. Igneous (cont.) Texture or crystal size depends mostly on cooling rate
1. intrusive  cools slowly
a. Large crystals
b. Ex. Granite
2. Extrusive  cools rapidly
a. Small crystals
b. Ex. Slate, Obsidian

9. Igneous (cont)
Some magma contains lots of dissolved gas  becomes trapped in rock  forms holes when it cools
Ex. Pumice

10. II. Metamorphic Rocks
A. Rocks that form from the alteration of existing rocks

11. Metamorphic (cont.) These changes occur by a. Heat b. Pressure
c. Chemical change

12. III. Sedimentary Rocks
A. Sedimentary rocks are made by compaction and cementation, this process is called LITHIFICATION

13. Conglomerate: Large rock made up of smaller rocks

14. Sedimentary (cont)
A. Texture: gives clues to the environment of where it was deposited

15. Sedimentary (cont) Grain Size: shows how far the sediment traveled
a. Large grain: did not travel far
b. Small grain: traveled farther

16. Sedimentary (cont) Grain Shape: shape of grains in rock
a. Angular: did not travel far enough to round out edges
b. Rounded: traveled far enough to round out the edges