1. Weathering

2. Bell Ringer What are the three main types of rocks?
Transformation through Heat and Pressure WITHOUT melting creates what type of rock?
Pressure of sediment over type creates what type of rock?
Cooled magma or lava create what type of rock?

3. Weathering

4. Weathering
Definition: the process by which rocks break down and change
Two Types:
Mechanical
Chemical

5. Mechanical Weathering
Definition: Process where rocks break into smaller pieces with NO change in their composition
Caused by:
Cold temperatures
Tectonic Processes
Biological Activity

6. Mechanical Weathering
1. Frost Wedging- The repeated thawing and freezing of water in the cracks of rocks
Water expands when frozen, chips away parts of the rock

7. Mechanical Weathering
2. Unloading- occurs when igneous rock becomes exposed through uplift and erosion Exfoliation-Occurs when pieces of the uplifted rock are weathered and chipped away

8. Mechanical Weathering
3. Biological Activity:
Organisms can cause Mechanical Weathering
Plant roots growing into cracks in rocks
Burrowing animals moving rocks
Decayed animals can produce acids (Chemical Weathering)

9. Chemical Weathering
Definition: Rocks undergo changes in their composition
Caused by:
Water
Oxygen
Carbon Dioxide
Acids

10. Chemical Weathering
Hydrolysis-The reaction of water with other substances
Oxidation-The reaction of oxygen with other substances

11. Chemical Weathering: Water
3. Water causes Chemical Weathering by absorbing gases from the atmosphere and ground
CO2 +Water  Carbonic Acid
Dissolves Rocks/Minerals
Stalactites/Stalagmites

12. Differential Weathering
Definition: When rocks weather at different rates
Caused by different mineral compositions
Sedimentary rocks weather more easily than igneous rocks

13. Statue of liberty
The statue of liberty is made of copper which is generally a brownish color
Has been affected by chemical weathering
Water reacting with the copper
Sulfuric acid formed by pollution (debatable)

14. Factors that Affect the Rate of Weathering