Weathering and Erosion

1
Weathering and Erosion
2
Weathering

• The process that breaks down rocks and other
  materials of Earths 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 Earths 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
https//www.youtube.com/watch?v_XnCTcjNpuc
14
2. Plant Growth
15
https//www.youtube.com/watch?veDA8rmUP5ZM
16
This is how paper beats rock!
17
3. Animal Actions
https//www.youtube.com/watch?vTtUz514rXKo
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
23
(No Transcript)
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

31
(No Transcript)
32
All this weathering can create interesting
landforms
33
Formation of Devils Tower, Wyoming
http//www.youtube.com/watch?vHsh3_ZMKq-A
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
http//gfycat.com/ColorlessHauntingBlackmamba?spe
ed2 underwater sinkhole
https//www.youtube.com/watch?vZmzTccYQGbw Corvet
te Museum sinkhole
http//abcnews.go.com/US/sinkhole-rent-best-deal-s
an-francisco/story?id27363928 Sinkhole for rent
37
Features of Karst Caves
38
Features of Karst Disappearing Streams
39
https//www.youtube.com/watch?vGNvnIl8hSUochemic
al weathering examples
40
Erosion
41
Erosion moves rock particles using four different
methods
42
1. Water Erosion

• Rivers, streams, and runoff

http//www.youtube.com/watch?vReCt2AcydCgfeature
related
43
2. Ice Erosion

• Glaciers

http//www.youtube.com/watch?vXOGbOOaPHswfeature
related
44
3. Wind Erosion
http//www.youtube.com/watch?vmecKnkc9qMk
45
4. Gravity

• Landslides, mudslides, slump and creep

http//www.youtube.com/watch?vZVjr4mii3cEfeature
player_embedded!
46
Summary

• Weathering breaks down 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

http//www.youtube.com/watch?vHjVSiuj7Lxk
47
Weathering and erosion review

• https//www.youtube.com/watch?vR-Iak3Wvh9c

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
Whats 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

58
(No Transcript)
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. 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
• https//www.youtube.com/watch?v403sT9CGRl0

• https//www.youtube.com/watch?vMYOmjQO_UMw
• Dust Bowl Intro
• http//en.wikipedia.org/wiki/Dust_Bowl
• Dust bowl Info