Weathering_and_Erosion PowerPoint presentation
- 3. Weathering • The breakdown do the materials of Earth’s crust into smaller pieces.
- 4. Physical Weathering • Process by which rocks are broken down into smaller pieces by external conditions. • Types of Physical weathering – Frost heaving and Frost wedging – Plant roots – Friction and impact – Burrowing of animals – Temperature changes
- 7. Plant Roots
- 8. Friction and Repeated Impact
- 11. Chemical Weathering • The process that breaks down rock through chemical changes. • The agents of chemical weathering – Water – Oxygen – Carbon dioxide – Living organisms – Acid rain
- 12. Water • Water weathers rock by dissolving it
- 13. Oxygen • Iron combines with oxygen in the presence of water in a processes called oxidation • The product of oxidation is rust
- 14. Carbon Dioxide • CO2 dissolves in rain water and creates carbonic acid • Carbonic acid easily weathers limestone and marble
- 15. Living Organisms • Lichens that grow on rocks produce weak acids that chemically weather rock
- 16. Acid Rain • Compounds from burning coal, oil and gas react chemically with water forming acids. • Acid rain causes very rapid chemical weathering
- 17. Karst Topography • A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams. • Created by chemical weathering of limestone
- 18. Features of Karst: Sinkholes
- 19. Features of Karst: Caves
- 20. Features of Karst: Disappearing Streams
- 21. Erosion • The process by which water, ice, wind or gravity moves fragments of rock and soil.
- 22. Water Erosion • Rivers, streams, and runoff
- 24. Wind Erosion
- 25. Mass Movements • Landslides, mudslides, slump and creep