What Are the Two Types of Weathering?

Notes Sect 5-1

Weathering

What are the two types of weathering?

A. Mechanical Weathering

1. What is mechanical weathering (KEY)?

2. Why does mechanical weathering increase the rate of chemical weathering? (see also Fig 2)

3. (a) Describe the process of frost wedging?

(b) Where is it more common? Why?

(c) What is talus?

4. (a) What is unloading?

(b) What is exfoliation?

(c) What kinds of structures are often formed by unloading? (Figure 4) 5. (a) How might a tree cause mechanical weathering?

(b) List some ways humans enhance mechanical weathering:

B. Chemical Weathering

6. What is chemical weathering? (key)

7. ______is the most important agent of erosion.

8. What gas becomes dissolved in water that helps enhance chemical weathering?______

9. What kind of minerals form when oxygen dissolved in water reacts?

10. What causes the yellow to reddish-brown coating on iron rich minerals?

11. What forms when water absorbs carbon dioxide (CO2) from the atmosphere or from decaying organic matter in the soil?

12. What does carbonic acid do to many minerals (especially carbonate minerals)? 13. Water in atmosphere can also dissolve sulfur oxides and nitrogen oxides (ex: SO2 and NO2) which when dissolved form acids that enhance chemical weathering. List some sources of these gases to the atmosphere

14. The chemical weathering of granite leads to the formation of ______minerals. These minerals are [tiny; large], so they can be carried far from shore by rivers entering the ocean.

C. Rate of Weathering

15. What are the two factors that affect how fast rock weathers?(key)

16. Why is the number of cracks in rock important to weathering?

17. Why are marble gravestones more susceptible to weathering than granite gravestones?

18. What are the two factors of climate that are most closely related to weathering?

19. The climate most favorable to chemical weathering has ______and ______.

20. Chemical weathering is [fast; slow] in both desert and polar regions.