1. Chapter 5 Weathering, Soils, & Mass Movements

2. Mechanical Weathering
Mechanical weathering-physical forces break rock into smaller pieces
Does not change the rock’s composition
same characteristics as the original rock

3. Mechanical Weathering
Surface area increases as breakup a rock

4. What Might cause this?

5. 1. Unloading Igneous rock are exposed through uplifting and erosion
of overlying rocks

6. 2. Frost Wedging
Mechanical breakup caused by the expansion of freezing water in cracks and crevices
Sections of rock that are wedged loose and fall apart

7. Frost Wedging

8. 3. Biological Activity
Plant roots grow into cracks in rock and wedge the rock apart
Burrowing animals move rocks to the surface
mole
worm

9. Chemical Weathering
Chemical weathering is the transformation (change) of rock into one or more new compounds

10. Chemical Weathering
Water
Most important agent in chemical weathering

11. Chemical Weathering- Examples
Iron on barrels coverts to rust
Iron + oxygen (from air) coverts to iron oxide (rust)

12. Chemical Weathering
Rain water mixes sulfur & nitrogen produced from the burning fossil fuels- coal & gasoline
Acid rain formed

13. Chemical Weathering “Acid Rain”
Acid rain increases the chemical weathering of stone monuments and structures

14. WHY?!?! Chemical Weathering The statue of liberty WAS orange
Statue of Liberty is green
WHY?!?!

15. Make a Venn Diagram and classify the following terms as either Mechanical, chemical or both
Fossil Fuels Now add 5 of your own
Animals
Water
Frost
Rust
Different chemical structure
Same chemical structure
Acid
Statue of Liberty
Unloading
Increased surface area
Roots
Change
Weathering