FACTORS THAT AFFECT THE RATE OF WEATHERING

1. Page 3 FACTORS THAT AFFECT THE RATE OF WEATHERING

2. Page 3 Mineral Composition • The harder the rock, the slower the rate of weathering • Composition dictates hardness which determines resistance to weathering.

3. WHICH LAYER IS MORE RESISTANT TO WEATHERING?LEAST RESISTANT? D A C B

4. Which rock is most resistant to weathering? F A C E B D

5. Which rock is least resistant to weathering? F A C E B D

6. You might also see it like this…

7. You might also see it like this…

9. Welcome to Huntington Cemetery! Step inside- IF YOU DARE- CREEPY

11. Wow! We haven’t even stepped inside and we have evidence of weathering in the gate! What process is this and is it physical or chemical? OXIDATION

12. We are going to look at cemetery rocks… (tombstones!) and observe the weathering that has occurred in them.

13. Since tombstones are dated we can even determine how long the weathering has occurred!

14. Here is a typical marble tombstone which used to be a very popular rock for cemeteries. What mineral largely composes the rock marble? Calcite

15. Calcite is very unstable at the earth’s surface in certain climate types. Which type in particular?

16. CO2 CO2 ACIDIFICATION Carbonation What weathering process causes the tombstones to “dissolve”? Is this chemical or physical?

17. Here is another type of tombstone. It is made up of slate.

18. Compare the two tombstones in the next picture. How do they differ in terms of the types of weathering that has occurred to each? How do they compare in appearance? Which appears more weathered?

19. Marble Slate

20. Which tombstone is older? Marble Slate

21. This means that rocks can weather at different rates! Marble Slate

22. This is called “Differential Weathering” Rocks weather at different rates due to differences in mineral composition. Some minerals are more stable at the earth’s surface than others! These take longer to weather.

23. Factors Affecting Weathering Rates Page 3 EXPOSURE- THE LONGER Weathering takes place on the outside surface of rocks. The more _____________ that occurs Weathering

24. Factors Affecting Weathering Rates Page 3 Particle Size- Weathering takes place on the outside surface of rocks. So the more _____________ that is exposed to weathering, the faster the rock will be broken down. • As a rock breaks into smaller pieces, the ____________ area increases, therefore the rate of weathering ___________. • Which will weather The fastest? surface area surface increases

25. Page 3 Surface Area Which will weather faster, solid rock or crushed rock? Why?? The answer and explanation on next page

26. Page 3 • The crushed rock of course! • The large rock is tightly packed and has less surface area exposed • The crushed rock is loosely packed and has more exposed.

27. Page 3 Factors Affecting Weathering Rates • Climate • #1 factor in weathering process • Dictates temperature and amount of moisture

28. Page 3 Climate- 1. Temperature: • In warm climates ____________is the dominant type of weathering. chemical physical b. In cold climates ____________ is the dominant type of weathering. 2. Precipitation: a. As precipitation increases, the amount of weathering byfrost action will __________. increase b. As precipitation increases , the amount of chemical weathering will__________________. increase warm 3. Chemical weathering is most rapid in __________, __________ climates. moist

29. Physical Weathering Works better in a cool and moist climate Chemical Weathering Works better in a hot and moist environment More water = more weathering Page 3 How does climate affect weathering?

30. Page 3 WHICH DIAGRAM IS AN ARID CLIMATE? HUMID CLIMATE? A B humid arid _________ Climate ________ Climate Sharp cliffs No vegetation Rolling hills vegetation Humid – more rounded Arid – more angular

31. No Page WHAT KIND OF CLIMATE SUPPORTS WEATHERING? HIGH PPT ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ LOW PPT COLD→→→→→→→→→→→→→→→→→→→→→→ HOT

32. Answers to Weathering and Climate Worksheet • H Yakutsk, USSR (-12°,31cm) • F Yuma, Arizona (22°,8cm) • B Minneapolis, Minnesota (5°,67cm) • D Charleston, S. Carolina (19°,123cm) • A Middletown, Connecticut (10°,95cm) • G Anchorage, Alaska (0°,37cm) • E Monterey, California (13°,52cm) • C Belize City, Belize (25°,200cm)

33. Answers to Weathering and Climate Worksheet • Warm and moist. The rate of chemical weathering increases, as temperature and moisture increases • Moist climate with alternating periods of freezing and thawing • Very dry or arid climate

34. D D D C C Page 4 Answers to Questions B B C A D B

35. D D D A D Pages 5 & 6 Answers to Questions C B A D D