Weathering, Erosion, and Deposition

1. Weathering, Erosion, and Deposition

2. 1. Weathering • Weathering is the breakdown of rock at the Earth’s surface. • Some of these changes happen quickly and some happen slowly. • There are 2 Types: • Mechanicaland Chemical

3. 2. Mechanical Weathering • Mechanical Weathering – the type of weathering where rock is broken down into smaller pieces without changing the chemical properties of the rock. • This can be caused by freezing and thawing, release of pressure, growth of plants, and actions of animals (including humans).

4. Example: Water seeps into a crack in a rock When the water freezes, it expands The force of the water expanding causes the rock to crack more. This is called ice wedging 3. Freezing and Thawing

5. 4. Plant Growth • Roots of trees and other plants enter into cracks of rocks. • As the plants get bigger, so do the roots. • The growing roots force the cracks further apart.

6. 5. Abrasion • Abrasion is the grinding away of rock by other rock particles. • These particles scrape away at other rocks like sandpaper on wood as they rub or roll against the surface.

7. 6. Chemical Weathering • Chemical weathering is the processes of breaking down rock through chemical changes. • 5 things that cause chemical weathering: water, oxygen, carbon dioxide, living organisms (like lichens) and acid rain. • Chemical weathering occurs more rapidly in warm wet climates.

8. 7. Chemical Change • Chemical Weathering causes the rock to experience a chemical change (changes its makeup) • Waterdissolves rocks over time • Oxygen causes oxidation (rusting) • Acid rain reacts with marble and limestone • Living organisms – plant roots produce weak acids to dissolve rock around the roots,

9. ACID RAIN OXIDATION

10. What type of weathering do each example cause? The roots of a plant An animal scratching Oxygen Water freezing Acid rain Wind Water A. Chemical Weathering B. Mechanical Weathering C. Both types of weathering CHECK- UP

11. What type of weathering???

12. What type of weathering???

13. What type of weathering???

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18. 8. Erosion • When rock and soil are movedfrom one place to another by natural forces, this is called Erosion. • The agents of Erosion are • Water (rain water runoff, streams, rivers, groundwater, and waves) • Ice(Glaciers) • Wind • Gravity ( landslides, mudslides, avalanches etc.)

19. 9. Sediment • The material moved by erosion is sediment. • Sediment is small, solid particles of rocks or organisms.

20. 10. Deposition • When the sediment being carried is dropped (or deposited) in a new area, it is called deposition. • Depositions can create new landforms like beaches and sand dunes.

21. Choose one of the following for each example: A.) Erosion B.)Deposition A river carrying sand Dropping sediment in a new location A glacier picking up a rock in it’s path. A beach is formed. How a sand dune is created How sediment is moved Sand being carried by the wind in a sandstorm. CHECK-UP