1. Weathering and Erosion

2. Weathering
The process that breaks down rocks and other materials of Earth’s crust into smaller pieces.

3. Erosion
The removal of rock particles by wind, water, ice, or gravity.

4. Weathering and erosion work together to wear down and carry away rocks on Earth’s surface

5. Avalon
Wildwood

6. Weathering

7. Weathering can happen two different ways - Physical and Chemical

8. Physical Weathering
Rock is physically broken down into smaller pieces

9. There are five types of physical weathering

10. 1. Freezing and thawing

11. Frozen soda cans

12. Frost Wedging

13. Frost Heaving

14. 2. Plant Growth

16. This is how paper beats rock!

17. 3. Animal Actions

18. Burrowing of Animals

19. 4. Friction and impact
River rocks are rounded and smoothed due to the repeated tumbling along the river bed as they roll downstream

20. Evidence of past liquid water on Mars!

21. 5. Temperature Changes
Rocks expand (get bigger) when they are hot, and contract (get smaller) when they are cold.

22. This brick wall has expanded and there is a visible crack

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

25. There are five types of chemical weathering

26. 1. Water
Water weathers rock by dissolving it

27. 2. Oxygen
Iron combines with oxygen in the presence of water in a processes called oxidation
The product of oxidation is rust

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

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

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

32. All this weathering can create interesting landforms

33. Formation of Devil’s Tower, Wyoming

34. Karst Topography
A type of landscape in rainy regions where there is limestone near the surface
Created by chemical weathering of limestone

35. Features of Karst: Sinkholes

36. Guatemala City sinkhole, 2010
underwater sinkhole
Corvette Museum sinkhole
Sinkhole for rent

37. Features of Karst: Caves

38. Features of Karst: Disappearing Streams

39. https://www. youtube. com/watch
chemical weathering examples

40. Erosion

41. Erosion moves rock particles using four different methods

42. 1. Water Erosion Rivers, streams, and runoff

43. 2. Ice Erosion
Glaciers

44. 3. Wind Erosion

45. 4. Gravity Landslides, mudslides, slump and creep

46. Summary Weathering breaks down rocks Erosion moves the rocks
It can be physical (ice, plants, animals, friction, temperature change) or chemical (water, oxidation, acid rain, carbon dioxide, living organisms)
Erosion moves the rocks
Together they produce soil

47. Weathering and erosion review

48. Soil
Soil is made from rocks, minerals (mostly sand and clay), and organic materials
Soil forms layers of different characteristics called horizons

49. What is soil? Soil is a material that forms the crust of the earth.
It comes from the weathering of rocks and decomposition of organisms.
It is formed very slowly.

50. What’s in soil?
Minerals
Organic matter
Air and water
Living organisms

51. Soil is found in layers called horizons

52. Soil-notice the layers in the soil

53. O horizon (green) O = Organic
The top, organic layer made up mostly of leaf litter and humus.
Humus is decomposed organic matter.

54. A horizon (dark brown) A = Topsoil. Dark colored
Where seeds germinate and roots grow. This is generally the most productive layer of soil.

55. B horizon (light brown)
B = Subsoil
Lighter colored
Contains clay and mineral deposits (iron, aluminum, etc)

56. C horizon (tan)
C = Parent Material
Layer of large unbroken rocks

57. R horizon (black)
R = Bedrock.
The solid rock that is under the soil

59. Areas with a lot of humus and topsoil are great for growing plants.

60. Mosaic
of closely
packed
pebbles,
boulders
Alkaline,
dark,
and rich
in humus
Weak humus-
mineral mixture
Dry, brown to
reddish-brown, with
variable accumulations
of clay, calcium
carbonate, and
soluble salts
Clay,
calcium
compounds
Desert Soil
(hot, dry climate)
Grassland Soil
(semiarid climate)

61. Forest litter
leaf mold
Acid litter
and humus
Acidic
light-
colored
humus
Humus-mineral
mixture
Light-colored
and acidic
Light, grayish-
brown, silt loam
Iron and
aluminum
compounds
mixed with
clay
Dark brown
firm clay
Humus and
iron and
aluminum
compounds
Tropical Rain Forest Soil
(humid, tropical climate)
Deciduous Forest Soil
(humid, mild climate)
Coniferous Forest Soil
(humid, cold climate)

62. Remainder of the period
Answer the review questions as a group.
Use this diagram to label the layers pictured in #4. You will still need to name and describe them (except layer E)
Sharpen and return pencils and cup

63. HW Answers Rock is weathered and eroded into soil
Weathering is the breaking down of rocks
Erosion is the removal of rocks

64. O- organic layer (green)-decaying organic matter
A-Topsoil (dk brown)- where seeds germinate
B- Subsoil (light brown) where minerals are found
C- Parent Material (tan)- large unbroken rocks
R-Bedrock (black)- solid rock
O horizon
A horizon
B horizon
C horizon
R horizon

65. 5. Topsoil is the most important layer of soil for plant growth. 6
5. Topsoil is the most important layer of soil for plant growth. 6. If an area has little topsoil we will see a little bit of plant growth because the plant is missing the most important layer for growth. 7. Deserts and arctic areas probably have little topsoil.

66. Soil Videos The value of soil
Dust Bowl Intro
Dust bowl Info