1. Weathering and Erosion pull out your HW

2. HW 14-1 #1-7 wind, water, and temperature change
Water that seeps into cracks freezes and expands, which widens and deepens crack with each freeze/thaw cycle.
Plant roots grow and expand, physically wedging rocks apart. Animal dig and burrow, which exposes new rock to weathering.
Mechanical weathering is a physical process, breaking large rocks into smaller rocks of the same chemical composition. Chemical weathering involves chemical reactions.

3. In oxidation, iron bearing minerals combine with oxygen to form red colored iron oxide. In hydrolysis, water and other substances in rock react chemically to form two or more new substances. In carbonation, carbonic acid converts minerals into carbonates.
Oxidation, hydrolysis, and carbonation are all chemical processes that weather rocks.
Acid precipitation forms when nitrogen oxides and sulfur dioxide released during fossil fuel combustion combine with water in the atmosphere to produce nitric, nitrous or sulfuric acid. When these acids fall back to earth they called acid precipitation.

4. Weathering
The breakdown of rocks on Earth’s crust into smaller pieces.
How did this rock get to look like this? PREDICT.

5. Mechanical (Physical) Weathering
Process by which rocks are broken down into smaller pieces by external conditions.
Types of Physical weathering
Frost heaving and Frost wedging (ice)
Plant roots
Friction and impact
Burrowing of animals
Temperature changes

6. Frost Wedging

7. Frost Heaving

8. Plant Roots

9. Friction and Repeated Impact

10. Burrowing of Animals

11. Temperature Changes

12. Mechanical Exfoliation is the peeling off of sheets of rock as they expand and crack.

13. Chemical Weathering
The process that breaks down rock through chemical changes.
The agents of chemical weathering
Water (Dissolution)
Oxygen (Oxidation)
Carbon dioxide (Carbonation)
Living organisms
Acid rain

14. Water: Dissolution
Water weathers rock by dissolving it

15. Oxygen: Oxidation
Iron combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust

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

17. Living Organisms
Lichens that grow on rocks produce weak acids that chemically weather rock

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

19. Chemical Weathering

20. Karst Topography
A type of landscape in rainy regions where there is limestone near the surface, characterized by caves, sinkholes, and disappearing streams.
Created by chemical weathering of limestone

21. Features of Karst: Sinkholes

22. Features of Karst: Caves

23. Features of Karst: Disappearing Streams

24. Transport Agent of Forces
Water
Wind
Ice (glaciers)
Gravity

25. Transport Agents - Water
Rain
Streams and rivers
Ocean dynamics
Ice (glaciers)

26. Streams

27. Stream Erosion and Deposition

28. Glaciers

29. Wind Transport of Dust

30. More Wind Transport of Dust – West Coast of Africa

31. Deposition Formation

32. Deposition Formation

33. Erosion
The process by which water, ice, wind or gravity moves fragments of rock and soil.

34. Water Erosion
Rivers, streams, and runoff

35. Ice Erosion
Glaciers

36. Wind Erosion

37. Mass Movements Landslides, mudslides, slump and creep
landslide clip.mpeg

38. Quiz Time – List weathering, erosion, both or neither
1.Waves are crashing on a sand beach.
2.Water expands as it freezes in the cracks of rocks.
3. Pebbles move down a stream with the current.

39. 4. Acid rain causes the decomposition of a statue in New York.
5. A Glacier slowly moves down a mountain.
6. A tree’s roots grow into the cracks of rocks.
7. A major volcano erupts

40. 9. A shovel is left outside and begins to rust.

41. 1. As the sand is moving there is definitely erosion; there is also abrasion from the sand gains colliding. Both

42. 2. This is frost wedging so it’s mechanical weathering
2. This is frost wedging so it’s mechanical weathering. There is no mention of movement. Weathering

43. 3. There is probably some weathering, but there is definitely erosion
3. There is probably some weathering, but there is definitely erosion. Erosion or Both

44. 4. Acid rain on a statue is chemical weathering
4. Acid rain on a statue is chemical weathering. This is mainly Weathering.

45. 5. A glacier moving down a mountain would have both weathering and erosion. Both

46. 6. A tree’s roots growing into cracks of rocks would be weathering
6. A tree’s roots growing into cracks of rocks would be weathering. Weathering
7. A tree’s roots growing into cracks of rocks would be weathering. Weathering

47. 7. A major volcanic eruption would involve both weathering and erosion
7. A major volcanic eruption would involve both weathering and erosion. Both

48. 8. The rusting of a shovel is oxidation. This is chemical weathering
8. The rusting of a shovel is oxidation. This is chemical weathering. Weathering

49. Vocabulary: Differential Weathering Surface area Climate topography
14-2 Rates of Weathering
Vocabulary:
Differential Weathering
Surface area
Climate
topography

50. Weathering Is a SLOW destructive process.
Carbonation weathers limestone one-twentieth of a cm (0.002) every 100 years.
Math Practice in 14-1: Limestone is dissolved by chemical weathering at a rate of 0.2 cm every 100 years. At this rate, after how many years would a layer of limestone 15 m thick completely dissolve?

51. 1. Composition
Differential Weathering: the process by which softer, less weather resistant rocks wear away at a faster rate than harder, more weather resistant rocks do
Sedimentary rocks (like limestone) weather rapidly compared to other type

52. 2. Amount of Exposure
The more exposure to the weathering agents: wind, water, gravity, the faster the rock will weather.
Surface Area: as rocks break into smaller pieces the surface area increases therefore weathering rate increases
Lab Demo: Sugar cube crushed up and sugar cube not crushed up. Volunteers to stir. Same temperature of water.
Hypothesize, which will dissolve quicker?
Analysis: What does amount of exposure/surface area have to do with time it takes to “weather”.

53. 3. Climate
Alternating hot/cold climates tend to weather faster because of the freezing and thawing cycle, causing frost wedging a form of mechanical weathering.

54. 4. Topography The elevation and slope of the land surface
Temperatures are generally colder higher up in elevation frost wedging is more evident.
The steeper the slope, the more rocks pulled downhill by gravity

55. 5. Human Activities
Mining, construction, recreational activities, etc.
View Mining Video (22 minutes)

56. 6. Plant and Animal Activities