1. Weathering and Erosion
Chapter 3

2. Essential Questions What processes break down rock?
What processes wear down and build up rock?
What causes weathering?
How fast does weathering occur?

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5. The process that breaks down rock and other substances.
Weathering
The process that breaks down rock and other substances.
Rate of Weathering Increases

6. Physical Weathering
Process by which rocks are physically broken down into smaller pieces .

7. Animal Actions Freezing and Thawing Plant Growth Release of Pressure
Physical Weathering
5 Types of Physical Weathering
Animal Actions
Freezing and Thawing
Plant Growth
Release of Pressure
Abrasion

8. Animals and insects loosen and break apart rocks in the soil.
Animal Actions
Animals and insects loosen and break apart rocks in the soil.

9. Freezing And Thawing
When water freezes in a crack of a rock it expands and makes the crack bigger.

10. Freezing And Thawing

11. Plant Growth
Plant roots enter cracks in rocks and as they grow force the cracks apart.

12. Plant Growth

13. Release of Pressure
As erosion moves material from the surface of a rock, pressure on the rock is reduced. This release of pressure causes it to crack and flake off like the layers of an onion.

14. Abrasion
Sand and other rock particles that are carried by wind, water, or ice can wear away exposed rock surfaces like sandpaper on wood.

15. Abrasion

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18. Review: Physical Weathering
Animals and insects loosen and break apart rocks in the soil.
When water freezes in a crack of a rock it expands and makes the crack bigger.
Plant roots enter cracks in rocks and as they grow force the cracks apart.
As erosion moves material from the surface of a rock, pressure on the rock is reduced. This release of pressure causes it to crack and flake off like the layers of an onion.
Sand and other rock particles that are carried by wind, water, or ice can wear away exposed rock surfaces like sandpaper on wood.
Animal Actions
Freezing & Thawing
Plant Growth
Release of Pressure
Abrasion

19. Chemical Weathering
The process that breaks down rock through chemical changes.

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21. Chemical Weathering Water Oxygen Carbon dioxide Living organisms
The 5 agents of chemical weathering
Water
Oxygen
Carbon dioxide
Living organisms
Acid rain

22. Water
Water weathers rock by dissolving it.

23. Oxygen
Iron combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust, making rocks soft and crumbly.

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

25. Carbon Dioxide
Alabama
The Great Blue Hole: Belize
Arizona

26. Living Organisms
As plant roots grow they produce weak acids. that dissolve the rock around the roots. Lichens that grow on rocks also produce weak acids.

27. Acid Rain
Compounds from burning coal, oil and gas react chemically with water forming acids.
Acid mixes with raindrops and cause very rapid chemical weathering of rock.

28. Review: Chemical Weathering
Water weathers rock by dissolving it.
Iron combines with oxygen in the presence of water in a processes called oxidation or rust, making rocks soft and crumbly.
CO2 dissolves in rain water and creates carbonic acid which easily weathers limestone and marble.
As plant roots grow they produce weak acids. that dissolve the rock around the roots. Lichens that grow on rocks also produce weak acids.
Compounds from burning coal, oil and gas react chemically with water forming acids. Acid mixes with raindrops and cause very rapid chemical weathering of rock.
Water
Oxygen
Carbon Dioxide
Living Organisms
Acid Rain

29. How Fast Does Weathering Occur?
The 2 most important factors that determine the rate at which weathering occurs are the:
1. Type of rock (what a rock is made of) – Certain rocks and minerals are naturally weaker than others, while others are more resistant (stronger).
2. The climate - Warmer, moister climates have the most weathering. Heat & Water speed up all chemical reactions. This is the most important factor in weathering.

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32. Home Learning Complete Lesson 2 Assess Your Understandings
Review & Assessment #1-10 Page 111
*BRING FLASHDRIVE 12/5
Gizmo #8 Dec. 11th
Vocabulary Quiz Dec. 12th
Edible Landform Dec. 13th
Fairchild Challenge Dec. 18th
Science in the News Dec. 20th