Rates of Weathering

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Rates of Weathering

• Lubov McKone
• Lauren Brooksby
• Andrew Beebe
• Stephanie Zuritis

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The Rate of Weathering

• The rate of weathering is the speed at which rock
  or soil is broken down.

Grand Canyon- 5-6 million years of weathering
Niagra Falls- 12,000 years of weathering
Zion Canyon- 200 million years of wind erosion
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Rock Composition

• The more soluble the minerals are that compose
  the rock the faster the rock will weather.

Granite
Rock Salt
Limestone
Mica
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Topography

• Topography affects the rate of weathering because
  if you have rough steep slopes, there is more
  area expose to rain, wind Therefore, because of
  what we have learned from surface area, we know
  that steeper slopes with weather faster than a
  flat area.

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Other Things That Affect The Rate Of Weathering

• Plants and animals can affect the rate of
  weathering because if you are in a place where
  there are lots of plants and animals, they will
  be walking, digging, burrowing and doing many
  things that would make rocks weather. So if you
  are in an area with more animals and plants, the
  rocks may weather faster.

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Amount of Exposure(surface area)

• When a rock is broken into smaller pieces,
  usually through mechanical weathering, the
  surface area of the rock is increased, creating
  more surfaces to weather. This will increase the
  rate of weathering of the rock.

For example, these broken? up halite crystals
will weather much faster than this full halite ?
crystal.
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Climate

• Rocks weather fastest in a hot, wet, climate?

This hot, arid climate has more weathering that
is caused by wind (slower).
Whereas weathering in this wetter climate depends
more on water (faster)
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Examples of Rate of Weathering
Rock Composition
The Rock Salt composition is halite which can
dissolve in water more easily.
Limestone is composed of calcite which will
dissolve slower in water than the Rock Salt.
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Surface Area
As a rock is broken up into more pieces the
surface area of the rock increases. Which then
lets mechanical and chemical weather more sides.