Weathering, Erosion, and Deposition

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Weathering, Erosion, and Deposition
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1. Weathering

• Weathering is the breakdown of rock at the
  Earths surface.
• Some of these changes happen quickly and some
  happen slowly.
• There are 2 Types
• Mechanical and Chemical

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2. Mechanical Weathering

• Mechanical Weathering the type of weathering
  where rock is broken down into smaller pieces
  without changing the chemical properties of the
  rock.
• This can be caused by freezing and thawing,
  release of pressure, growth of plants, and
  actions of
• animals (including
• humans).

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3. Freezing and Thawing

• Example
• Water seeps into a crack in a rock
• When the water freezes, it expands

• The force of the water expanding causes the rock
  to crack more.
• This is called ice wedging

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4. Plant Growth

• Roots of trees and other plants enter into cracks
  of rocks.
• As the plants get bigger, so do the roots.
• The growing roots force the cracks further apart.

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5. Abrasion

• Abrasion is the grinding away of rock by other
  rock particles.
• These particles scrape away at other rocks like
  sandpaper on wood as they rub or roll against the
  surface.

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6. Chemical Weathering

• Chemical weathering is the processes of breaking
  down rock through chemical changes.
• 5 things that cause chemical weathering water,
  oxygen, carbon dioxide, living organisms (like
  lichens) and acid rain.
• Chemical weathering occurs more rapidly in warm
  wet climates.

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7. Chemical Change

• Chemical Weathering causes the rock to experience
  a chemical change (changes its makeup)
• Water dissolves rocks over time
• Oxygen causes oxidation (rusting)
• Acid rain reacts with marble and limestone
• Living organisms plant roots produce weak acids
  to dissolve rock around the roots,

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ACID RAIN
OXIDATION
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CHECK- UP

• A. Chemical Weathering
• B. Mechanical Weathering
• C. Both types of weathering

• What type of weathering do each example cause?
• The roots of a plant
• An animal scratching
• Oxygen
• Water freezing
• Acid rain
• Wind
• Water

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What type of weathering???
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What type of weathering???
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What type of weathering???
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What type of weathering???
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What type of weathering???
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What type of weathering???
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What type of weathering???
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8. Erosion

• When rock and soil are moved from one place to
  another by natural forces, this is called
  Erosion.
• The agents of Erosion are
• Water (rain water runoff, streams, rivers,
  groundwater, and waves)
• Ice (Glaciers)
• Wind
• Gravity ( landslides,
• mudslides, avalanches etc.)

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9. Sediment

• The material moved by erosion is sediment.
• Sediment is small, solid particles of rocks or
  organisms.

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10. Deposition

• When the sediment being carried is dropped (or
  deposited) in a new area, it is called
  deposition.
• Depositions can create new landforms like beaches
  and sand dunes.

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CHECK-UP

• Choose one of the following for each example
• A.) Erosion
• B.)Deposition

• A river carrying sand
• Dropping sediment in a new location
• A glacier picking up a rock in its path.
• A beach is formed.
• How a sand dune is created
• How sediment is moved
• Sand being carried by the wind in a sandstorm.