1. Weathering, Erosion, Soil, Mass Movement ppt NOTES Define Terms on Quizlet Use Textbook, ppt for definitions Ch 7, terms
Weathering
Erosion
Igneous Rocks
Mechanical Weathering
Sedimentary Rocks
Frost Wedging
Metamorphic Rocks
Exfoliation
Lithification
Chemical Weathering
Creep
Hydrolysis
Flow
Oxidation
Slide, Mudslide
Abrasion
Deposition
Loess
Soil
Glacier
Soil Profile
Cirque
Humus
Moraine
Permafrost
Kettle Hole
Soil Fertility
Rill Erosion
Gully Erosion
**NOTE ON MY WEBPAGE –
under ES LINKS there are SCIENCE GLOSSARY RESOURCES FOR LOOKING UP BETTER DEFINITIONS.. USE IT!! 

2. Igneous Rocks Sedimentary Rocks Metamorphic Rocks Lithification Creep
Flow
Slide, Mudslide
Abrasion
Loess
Glacier
Cirque
Moraine
Kettle Hole
ES Weathering Erosion Link with Games
Excellent to preview

3. Weathering and Erosion
Video Clip 8 min Strangest Geologic Formations on Earth

4. Changes occur every day to Earth’s rocks and surface features.
Weathering
Changes occur every day to Earth’s rocks and surface features.
Erosion is the removal and transport of weathered material from one location to another.
Weathering is the chemical and physical processes by which rocks on or near Earth’s surface break down and change.
Video 13 mins Planet Earth Amazing nature scenes – created by Weathering and Erosion

5. There are 2 Types of Weathering. you must KNOW.
1. Mechanical (or Physical ) Weathering.
2. Chemical Weathering
Mechanical weathering, or physical weathering, is the process by which rocks and minerals break down into smaller pieces without changing their composition.
Mechanical weathering does not involve any change in a rock’s composition.

6. Mechanical (Physical) Weathering
Process by which rocks are broken down into smaller pieces by external conditions.
Types of Mechanical Weathering:
Frost heaving and Frost wedging
Plant roots
Friction and impact
Burrowing of animals
Exfoliation

7. Mechanical Weathering
Temperature
In many places on Earth’s surface, water collects in the cracks of rocks and rock layers.
If the temperature drops to the freezing point of water, it freezes, expands, exerts pressure on the rocks, and may cause them to split.
When the temperature then increases, the ice in the cracks of rocks and rock layers melts.
Frost wedging is the repeated thawing and freezing of water in the cracks of rocks.

8. Frost Wedging or Heaving

9. Plant Roots

10. Friction and Repeated Impact / Burrowing of Animals

11. Mechanical Weathering
Pressure
Bedrock at great depths is under pressure from the overlying rock layers.
When the overlying rock layers are removed, the pressure on the bedrock below is reduced.
The bedrock surface, formerly buried, is then able to expand, and long, curved cracks known as joints can form that lead to exfoliation.
Exfoliation is the process by which outer rock layers are stripped away over time.
The roots of plants can also exert pressure causing rocks to split.

12. Exfoliation – the surface looks smooth.

13. So the 2 most Important Factors in Mechanical Weathering are..
Temperature
Ex.: Frost Wedging
Pressure
Ex. Exfoliation, Plant Roots

14. Chemical Weathering
is the process by which rocks and minerals undergo changes in their composition as a result of a chemical reaction.
Reactions result in the formation of NEW minerals and the release of dissolved substances.

15. Agents of Chemical Weathering
Water-
Dissolves rocks and minerals
Medium through which reactions occur
Hydrolysis- the chemical reaction of water with other substances
Oxygen
Oxidation- is the chemical
reaction of oxygen with other
substances.
2Fe3O4 + ½ O2 ® 3Fe2O3

16. Carbon Dioxide
Produced during respiration (breathing)
Combines with water to produce carbonic acid falls as precipitation
Carbon dioxide dissolves rocks
H2O + CO2 ® H2CO3
Acid Precipitation (rain)
Oxidation of sulfur dioxide and nitrogen dioxides
Acid precipitation is any type of precipitation that has a pH below 5.6.
This is very destructive to living things.

17. Chemical Weathering Acid Precipitation
Acid precipitation is caused mainly by the oxidation of sulfur dioxide and nitrogen oxides that are released into the atmosphere by human activities.
These two gases combine with oxygen and water in the atmosphere to form sulfuric and nitric acids.
Acid precipitation is precipitation that has a pH value below 5.6, the pH of normal rainfall.

18. The Rate of Weathering How Fast Do Things Weather??
Climate: #1 Factor in weathering process.
The climate determines the amount of precipitation, temperature, and evaporation. Moisture and Temp.
This is why there is intense chemical weathering in tropical areas.
Ex) rainforests and the equatorial region
Rock type and Composition
Sedimentary rocks break down more easily than metamorphic rocks or igneous rocks
Surface area
The higher the total surface area, the more weathering occurs because more area is exposed. Smaller pieces break down faster than Larger.

19. Weathering Rates Surface area exposure
(More surface area = greater weathering)
Which rock
Piece will weather
The fastest?
Answ: Rock w greatest
Surface area facing
Waves.

20. WEATHERING INCREASES SURFACE AREA MEANS
MORE WEATHERING CAN OCCUR- small pieces!

21. Surface Area SELF CHECK: Which will weather faster? WHY?
- solid rock or crushed rock? See pic…

22. ANSWER for last slide- the crushed rock.. Erosion and Deposition
Erosion- the removal and transport of weathered material from one location to another.
Deposition- during erosion, WHEN transporting slows and materials are dropped or deposited into different places.

23. How Climate effects both types of weathering?
Physical Weathering
Works better in a COOL and DRY climate.
Chemical Weathering
Works better in a HOT and MOIST environment
More water = more weathering

24. Causes of Erosion
Gravity erodes by pulling all materials downhill due to their weight.
Water
Water has the most potential for erosion, because:
It has the highest volume
It is the fastest
It moves things down steep slopes with the help of gravity.
Rill Erosion- erosion by running water in small channels on the side of a slope.
Gully Erosion- erosion on the side of a slope in deep, wide channels.

25. Development Rill Erosion – small channels see Left pic.
Gully Erosion – small channels become wide and deep – see Rt pic

26. Which is Rill Erosion? & Which is Gully Erosion?

27. Coastal WEATHERING - CHANGES OF Deposition And Erosion
Rivers slow down as they reach the ocean or a larger body of water.
As the water slows, it begins to DEPOSIT the larger sediments.
This is seen in deltas.
A delta is a triangular deposit that forms where a stream or river enters a large body of water.
Examples:
The Mississippi Delta is on the left.
The Nile River Delta is on the right.

28. Ocean EROSION
Ocean currents, waves, and tides carve out (erode) cliffs and arches.

29. ON Shorelines – deposition of Sand particles form sand dunes and beaches.
On beaches, sand is constantly being eroded and deposited offshore making sand bars.
If this deposition continues, the sand bars become
“Barrier Islands”.

30. Glacial ICE - Erosion Glaciers cover <10% of the Earth’s surface.
Glaciers scrape and gouge out large sections of the Earth’s landscape.
Glaciers erode by carrying large rocks and debris over great distances.

31. Wind Erosion The wind carries small particles easily.
- happens in areas with limited precipitation and normally high temperatures.
The wind carries small particles easily.

32. Plants, Animals, and Humans - Erosion
We cause erosion simply by existing. This happens if we are doing construction or even if dirt is stuck to our shoes. Plant roots, Animal holes.

33. Soil - is one of the major products of weathering.
-Is the loose covering of broken rock particles and humus.
-Is the Result of physical and chemical weathering and biological activity

34. What is Soil ?
Soil is a loose covering of broken rock particles and decaying matter.
The production of soil begins when weathering breaks down rock into smaller pieces.
Organisms live in this material.
Eventually these organisms die
and their nutrients are added to the
weathered material to form soil.
Video What’s the Dirt on Dirt? 3:43 mins
Video Kinds of Soil 3 min

35. Soil Profiles and Soil Horizons
A Soil Profile is a vertical sequence of soil layers.
Poorly developed soils show little distinction between layers
A Soil Horizon is a distinct layer or zone within a soil profile. There are 3 major horizons.
Horizon A - has a high concentration of organic matter and humus (decaying organic matter)
These soils are normally dark colored (gray to black)
Horizon B- has sub-soils enriched with clay minerals
Horizon C- contains weathered parent material
Parent Rock on bottom. SEE PIC next slide

36. Soil Horizons underground.
A soil horizon is a distinct layer or zone within a soil profile. There are 3 major horizons.

37. Soil Composition
Parent material -is the original bedrock that lies deep within the surface.
Residual soil -is soil located above its parent material.
Transported soil -is soil that has been moved away from its parent material.

38. Topography
Sloped areas, Hills, Mountains – have thinner soil layer and larger soil particles and may be infertile due to run-off. Not good growing.
In Valley Areas- the soil is often thick and fertile- Good Growing

39. Soil Types Polar soils: Permafrost is permanently frozen ground
Are located at places of high latitudes and high elevations
Ex) Greenland, Canada, Antarctica
Have good drainage
Have no distinct horizons
Contain areas of permafrost.
Permafrost is permanently frozen ground

40. Temperate soils: Desert soils: Tropical soils:
Are in places with an annual rainfall > cm
Vary from very fertile soils to aluminum-rich clays
Desert soils:
In areas with <25 cm of annual precipitation
Areas with a high level of accumulated salts
Cannot support much vegetation
Tropical soils:
Are in areas with high temperatures and heavy rainfall
Soils are intensely weathered and often infertile
Most often red

42. Soil Textures Soils are classified according to their particle size.
Lg to Small SAND > SILT > CLAY
affects its capacity to retain moisture and ability to support
plant growth.

43. Soil Fertility
Soil fertility is the measure of how well a soil can support the growth of plants.
Factors of fertility
Availability of nutrients and minerals
Number of microorganisms present
The amount of precipitation available
Topography
Level of acidity

44. Soil Color
A soil’s composition and the climate in which it develops are the main factors that determine a soil’s color.
Topsoil is usually dark-colored
Red and yellow soils may be the result of oxidation of iron minerals.
Yellow soils are usually poorly drained and are often associated with environmental problems.
Grayish or bluish soils are common in poorly drained regions where soils are constantly wet and lack oxygen

45. Soil Texture Triangle Trick to READING is: 1
Soil Texture Triangle Trick to READING is: 1. Find Soil on Sides – sand, silt, clay. 2. Follow LINES for all three % like the number is tilted to meeting area to identify SOIL TYPE. See EX next slide.

46. Chapter Assessment
Multiple Choice
4. What is the texture of a soil that is 60 percent silt, 30 percent sand, and 10 percent clay?
a. clay c. loam
b. sandy loam d. silt loam
Follow the lines from the percentage of silt, sand, and clay on the soil textual triangle to identify a soil’s texture.

47. The Rock Cycle
The rock cycle is the continuous changing and remaking of rocks. Learn the processes of change. See next slide..

48.
Video Rock Types
Best video 3:45
Video Flourescent Rocks

49. Igneous Rocks
Process: Igneous rocks are formed from the Solidification or crystallization of Magma. Magma is molten rock below ground. Lava is molten rock on the Earth’s surface.

50. Formation of Magma
The main factors involved in the formation of magma are temperature, pressure, water content, and mineral composition.
Temperature generally increases with depth in Earth’s crust, a phenomenon known as the geothermal gradient.

51. Types of Igneous Rocks
Extrusive rocks are igneous rocks that cool quickly on the surface of the Earth.
Intrusive rocks are coarse-grained rocks that cool slowly beneath the Earth’s surface.

52. Classifying Igneous Rocks
Felsic rocks, such as granite, are light-colored and have high silica contents.
Mafic rocks, such as gabbro, are dark-colored, have lower silica contents, and are rich in iron and magnesium.
Intermediate rocks, such as diorite, have some characteristics of both felsic and mafic rocks.

53. Formation of Sedimentary Rocks
Processes: Weathered and Eroded Sediments are Cemented and Compacted together to form this rock type.
Note: Sediments are made by weathering. These are found on the surface of Earth Mainly and include FOSSILS.

54. Lithification is the transformation of sediments into sedimentary rock by COMPACTION AND CEMENTATION.
This is done by weathering (rains) and deposition and adding pressure.

55. Metamorphism- formed under heat and pressure.
Metamorphism is the process that makes rocks change form while remaining solid
Temperature is increased due to their deep burial within the Earth. The temperature of the Earth heats the rocks allowing them to change shape.
Pressure is increased by the vertical depth beneath the Earth or by mountain building forces.

56.
Video: 10 Rarest Rocks in the World 4 mins

57. Ch 8: Mass Movement, Wind, and Glaciers

58. Materials weight- resulting from gravity
Mass movements are the down slope movement of loose sediment and weathered rock resulting from the force of GRAVITY.
Variables that contribute to Mass Movement
Materials weight- resulting from gravity
Materials resistance to sliding,
Not enough or having too much water makes a slope unstable.
Triggers (like earthquakes) that shake the earth material loose.

59. Ways that rocks move… Slide- moves a block of material
Flow- involves a mixing of particles within a moving mass
Fall- free fall of Earth material

60. Types of Mass Movements
Creep- a slow, steady, downhill flow of loose, weathered Earth material.
Creep happens over an extended period of time.
You can look at structures for evidence of creep.
Objects will tilt.
Trees will bend.
Walls, foundations, and pipelines will crack.

61. Flows In Flows- Earth materials flow as if they were a thick liquid
Flows can move anywhere from a centimeter per year to kilometers per hour
Mudflows are swiftly moving mixtures of mud and water that are triggered by earthquakes and vibrations. They are also triggered by volcanic activity melting snow in the surrounding area.

62. Slides - A landslide is a rapid, down slope movement of Earth materials that occurs when a thin block of loose, soil, rocks, and debris separates from the underlying bedrock
These can block rivers and cause flooding
A rockslide is a landslide where a sheet of rock moves downhill. These are often triggered by earthquakes

63. Slumps
A slump is when a mass of material in a landslide rotates and slides along a curved surface.
Slumps are often triggered by earthquakes

64. Avalanches
Avalanches are landslides that occur in mountainous area with think accumulations of snow.
Radiation melts snow and then refreezes overnight. New snow falls on top can slip off the surface and slide easily downhill.

65. Rock falls are simply when rocks fall from their previous location
Rock falls are simply when rocks fall from their previous location. This occurs on steep road cuts and on rocky shorelines.

66. Prevention of Mass Movements
Lower the slopes of dug out trenches
Dig trenches in steep slopes for drainage
Put up retaining walls to block rocks and sediment

67. Wind Erosion and Transport
Wind picks up and carries sediments in the same way that water does, but it cannot carry particles as large.
The exception to this is hurricanes, tornadoes, and strong storms.
The ability of wind to erode materials is less than other means of erosion (like water and ice).

68. Abrasion occurs when WIND BLOWS particles like sand and they rub against the surface of rocks and other materials- create Erosion features. .
This wears away rocks (Baja Mushroom in Baja, California)
Ventifacts are rocks shaped by windblown sediments.

69. Wind Deposition
As wind speed decreases, some wind-blown sand and materials drop out of the air stream to form a deposit on the ground.
Formation of SAND Dunes
A dune us a pile of wind-blown sand that accumulates over time on the shoreline.

70. Migration
Dunes protect coastal vegetation, but they still migrate due to wind
These dunes can block highways and bury houses

71. Loess
Wind can carry fine, lightweight particles of Silt and Clay over long distances, These particles make thick wind-blown silt deposits called a Loess.
These are very fertile soils, because they contain abundant minerals and nutrients.

72. Glacier-are a large moving mass of ice
Glaciers form near Earth’s poles and in mountainous areas with high elevations
Cold temperatures keep fallen snow from completely melting and each year, the snow that has not melted accumulates in an area called a snowfield
The total thickness of the now layer increases as years pass and a glacier begins to form
Video 2 mins glacier with Canadian Accent.. lol

73. There are 2 types of glaciers
Valley glaciers- glaciers that form in valleys in high, mountainous areas
Movement occurs when growing mass becomes too heavy to maintain rigid shape and begins to flow like thick liquid that moves downhill
The movement carves v-shaped valleys into U-shaped valleys

74. Continental glaciers- glaciers that cover broad, continent-sized areas
The glacier is thickest at its center and this forces the rest of the glacier to flatten out in all directions
These are also called ice sheets

75. Glaciers are the greatest erosional agents..
This is due to:
Size
Weight
Density

76. When valley glaciers move, they break off pieces of rock by a process called plucking.
Glaciers have rocks embedded on their surface
These rocks make scratches in the bedrock, like sandpaper on wood
Striations- small scratches
Grooves- large scratches
These scratches help to show glacial history and movement

77. Features of Glacial Erosion
U-shaped valley
Cirque- deep depression carved by valley glaciers
Arete- a sharp, steep ridge that is formed when two cirques meet on opposite sides of a valley
Horn- a steep pyramid-shaped peak that forms if there are glaciers on 3 or more sides of a mountain top
Most famous is Matterhorn in Switzerland
Hanging valley- tributary valley that enters a
U-shaped valley from high up a mountainside

79. Glacial Deposition
Till- mixed debris that glaciers carry embedded in their ice, tops, sides, and front edges
Moraines- ridges consisting of till deposited by glaciers
Terminal- moraine at foot of glacier
Lateral- moraine on side of glacier

80. Top Left Till
Top Right- Moraine
Top Center- Medial Moraine
Bottom Left- Moraine
Bottom Right- Lateral Moraine

81. Outwash plain- area at leading edge of glacier, where melt water streams flow and deposit outwash
Drumlin- elongated landform that results when a glacier moves over an older moraine
Esker- a long, winding ridge of layered sediments deposited by streams that flow beneath a melting glacier

83. Glacial Lakes
Blocks of ice can break off a glacier and be covered by sediment
When the ice melts, it leaves behind a depression called a kettle hole or Lake.
The hole can fill up with precipitation and runoff to form a kettle lake
If a cirque fills with water, it is called a cirque lake
See pic.

84. http://glencoe. mheducation
Set 1: 8 Self Check quick questions – Do Link and check.
Set 2: 8 Self Check quick questions- Do Link and check
Set 3: 8 Self Check quick questions- Do Link and check
READ: IT IS REQUIRED THIS UNIT to do Weathering STUDY TIP QS 1-23 for grade. Copy QS and Answer or Answer on a Print out. On webpage