1. Rocks
And the Rock Cycle

2. Chemical vs. Physical Stability of Rocks
Tendency to keep its chemical structure
Lower temperatures make more stable rock
Higher temp. less stable
Have natural weaknesses in structure
Break along JOINTS

3. 3 Rock Types:
Sedimentary
Igneous
Metamorphic

4. The Rock Cycle

6. Igneous Rocks Formed by volcanic activity
Lava melted rock on Earth’s surface
Molten rock under Earth’s surface magma

7. Fractional Crystallization
Partial Melting
Dif. Minerals melt @ dif. temperatures
Fractional Crystallization
Dif. Minerals form dif. Times
Larger crystals usually 1st

8. Igneous Rocks Large crystals - cooled slowly underground
Small crystals - cooled quickly at surface
Quick cooling can produce bubbles or a glass too

9. Igneous Rocks Felsic IR (most light color) Mafic IR (dark color)
High silica
Granite, pumice
Mafic IR (dark color)
Low silica
High in iron & magnesium
Basalt, gabbro

10. Intrusive Igneous Rock Extrusive Igneous Rock
Formed underground
Cools slowly
Large crystals
Granite
Formed above ground
Cools quickly
Small crystals
Pumice

11. Sedimentary Rocks:
Form surface
Fossils

12. Lithification is a process where sediment compacts under pressure, expel fluid and become solid rock

13. Sedimentary Rocks

14. Types Of S.R. Chemical Organic Clastic Evaporates Halite, gypsum
coral, clams, plankton
Limestone
Clastic
Broken pieces of older rock
Sandstone, conglomerate

15. Limestone
Fossilized
Coral Reef

17. Metamorphic Rocks
High pressure & temperature deep inside near magma

18. Metamorphic Rocks
Foliated - striped
Non-foliated