2. Have you seen… Potholes in roadways? Broken concrete in sidewalks and curbs? These are examples of Weathering.

3. What is Weathering? The process of rocks breaking down into smaller pieces.

4. Not to be confused with… …Erosion

5. Types of Weathering. Chemical Weathering and Mechanical Weathering aka Physical Weathering

6. Mechanical Weathering. Mechanical weathering is the physical break down of a rock without changing its chemical composition.

7. Agents of Mechanical Weathering: Ice Wedging Plant Roots Friction and Repeated Impact Burrowing of animals Temperature Changes Gravity

8. Ice Wedging

9. Plant Roots

10. Friction and Repeated Impact

11. Burrowing animals

12. Temperature Changes

13. Gravity

14. Weathering treasures…

15. Not so lucky…

16. Chemical Weathering. Chemical Weathering is the process in which the chemical makeup of rock is changed.

17. Agents of Chemical Weathering: Carbonation Oxidation Acid Rain Plant Acid

18. Carbonation When water combines with carbon dioxide in the air or soil, carbonic acid forms. When carbonic acid comes in contact with rocks like limestone and marble they dissolve.

19. Oxidation When you see rusty cars, red soil, or red stains on rocks, you are seeing oxidation. Oxygen reacts with iron so when some iron-containing minerals are exposed to oxygen, they can weather into minerals that are like rust. This leaves the rock weakened, and it can break apart.

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

21. Plant Acids Plant roots produce acids that react with rocks. When this acid dissolves with some minerals in rocks the rock is weakened. Over time, it can break into smaller pieces.