1. Weathering and Erosion NOTES

2. Weathering
The breakdown do the materials of Earth’s crust into smaller pieces.

3. Mechanical Weathering
Process by which rocks are broken down into smaller pieces by external conditions.
PHYSICAL CHANGES ONLY
Types (Causes) of Mechanical weathering
Freezing & Thawing (Ice wedging)
Plant Growth (roots)
Abrasion (Friction and impact)
Animal Actions (Burrowing of animals)
Release of Pressure

4. Ice Wedging

5. Plant Growth/Plant Roots

6. Abrasion (Friction and Repeated Impact)

7. Animal Actions (Burrowing of Animals)

8. Release of Pressure (includes temperature changes)

9. Chemical Weathering
The process that breaks down rock through chemical changes.
The agents (Causes) of chemical weathering
Water: dissolves rock
Oxygen: oxidation (rust)
Carbon dioxide: carbonic acid (limestone)
Living organisms: lichens
Acid rain: pollution

10. Water
Water weathers rock by dissolving it

11. Oxygen
Iron combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust

12. Carbon Dioxide CO2 dissolves in rain water and creates carbonic acid
Carbonic acid easily weathers limestone and marble

13. Living Organisms
Lichens that grow on rocks produce weak acids that chemically weather rock

14. Acid Rain
Compounds from burning coal, oil and gas react chemically with water forming acids.
Acid rain causes very rapid chemical weathering

15. Sinkholes

16. Caves

17. Disappearing Streams

18. Erosion
The process by which water, ice, wind or gravity moves fragments of rock and soil.
Moves rock particles
Constructive or destructive
Fast or slow process

19. Water Erosion
Rivers, streams, and runoff

20. Glaciers (Ice Erosion)

21. Wind Erosion

22. GRAVITY: Mass Movements
Landslides, mudslides, slump and creep
landslide clip.mpeg