Weathering

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Weathering
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DEFINITIONS
WEATHERING Brainstorm 1) What is it? 2) What can cause it? 3) How does weathering change the surface of the Earth? - Possible Causes
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WEATHERING

• Weathering the breaking down of rock into
  smaller and smaller pieces.
• Is weathering constructive, destructive, or both?
  Why?
• -Weathering is destructive- it tears down rocks
  and landforms.

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2 Types of Weathering
Brain-storm 1) What can cause each type of weathering? WEATHERING WEATHERING
Brain-storm 1) What can cause each type of weathering? Mechanical 2) Chemical
Brain-storm 1) What can cause each type of weathering? Breaking down rocks by physical means Chemical breakdown of rock and minerals into new substances
Brain-storm 1) What can cause each type of weathering? Possible causes Possible causes
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MECHANICAL WEATHERING

• 1. ANIMALS
• Little animals also help weathering by burrowing
  and digging through the ground.

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MECHANICAL WEATHERING

• 2. Ice Wedging when water gets into cracks of a
  rock, freezes thaws over over again splits
  the rock

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MECHANICAL WEATHERING
Ice
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MECHANICAL WEATHERING

• 3. PLANT GROWTH
• Roots of plants also push into the rocks and
  break them apart. They act like wedges and push
  the rocks apart.

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MECHANICAL WEATHERING

• 4. RELEASE OF PRESSURE- as erosion moves sediment
  from the surface, pressure is reduced. The
  outside of the rock begins to flake off

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MECHANICAL WEATHERING NONLIVING CAUSES

• 5. Abrasion- sediments carried by wind, water, or
  ice wear away rock by hitting scraping against
  other rock

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Abrasion

• Wind
• sandstone shapes
• eroded by coastal
• winds 

Sandblasting
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Abrasion

• WATER - rubs fragments against
• each other and wears away the
• surface of the rock by abrasion.
• The faster the water, the greater the erosion

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Abrasion

• Ice- Glaciers

• The glacier gouges out chunks of rock and leaves
  scratches on the rock called striations

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CHEMICAL WEATHERING

• CHEMICAL WEATHERING the chemical breakdown of
  rock and minerals into new substances

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CHEMICAL WEATHERING

• Water is considered to be the universal solvent.
  It dissolves many things including rock
• Over time, water can break down even hard rock
  like granite

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CHEMICAL WEATHERING

• 2) Oxygen
• Oxidation (rust)
• is a chemical reaction in which an iron combines
  with oxygen.

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CHEMICAL WEATHERING

• 3) Carbon Dioxide (CO2)
• -CO2 mixing with water
• creates Carbonic Acid that
• slowly dissolves limestone.
• (Acid in groundwater)
• -Caves

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CHEMICAL WEATHERING

• 4) Living Organisms
• Acids from decaying plants or fungi such as
  lichens breaks down rocks

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CHEMICAL WEATHERING
5. ACID PRECIPITATION

• is rain or snow that contains more acids than
  normal due to air pollution.
• The acid dissolves and eats away the rock

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WEATHERING
How does weathering change the surface of the Earth?
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Mechanical Weathering
Living Plant Roots of plants also push into the rocks and break them apart
Living Animal burrowing and digging through the ground
Non-living Ice (glaciers) -water gets into cracks of a rock, freezes thaws over over again splits the rock -scratches on the rock called striations
Non-living Wind wears away the surface of the rock by abrasion
Non-living Water rubs fragments against each other and wears away the surface of the rock by abrasion.
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Chemical Weathering
Living Plants Acids from decaying plants or fungi such as lichens breaks down rocks
Non-living Water universal solvent. It dissolves many things including rock
Non-living Acid rain rain or snow that contains more acids than normal due to air pollution. -acid dissolves or eats away the rock
Non-living Ground-water CO2 mixing with water creates Carbonic acid that slowly dissolves limestone
Non-living Oxidation chemical reaction in which an element combines with oxygen to form an oxide
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FORCES THAT CAUSE
Weathering Weathering Weathering Weathering
1) Mechanical 1) Mechanical 2) Chemical 2) Chemical
Living Nonliving Living Nonliving
Plants Ice - (Glaciers) Plants Water
Plants Acid rain
Plants Wind Groundwater
Animals
Animals Water Oxidation
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Interactive Weathering

• How are materials from the earth broken down?