Weathering, Erosion and Soil
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Did you know?
Weathering and erosion are not the same thing.
Water is so powerful! Imagine a rock sitting under a waterfall. The water can
make the rock change shape. It could even make rocks crack apart. This is called
weathering. Weathering is the breaking down of rocks into smaller pieces. Wind
can also weather things. Now, imagine that water carries pieces of rock to a new
place. When rock moves, it is called erosion. Erosion is the movements of rocks
and rock pieces. Discovery Communications, LLC
WeatheringMechanical Weathering Read pp. 116-117A (Yes, read the pictures)
Mechanical Weathering-the breaking up of rocks by physical force.
Four Types:
Ice Wedging
Example:
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Example:
Plant Root Growth
Example:
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Example:
Picture:
Picture:
Picture:
Picture:
1. Explain how moving water can impact rock.
2. What do all four processes of mechanical weathering have in common?
3. Of the four processes of mechanical weathering, which two processes seems most alike and
why?
Chemical Weathering Read pp.118-119A
Chemical Weathering-when rocks and minerals undergo a chemical change
-Changes the make-up of a rock
Two Types
Dissolving
Example: _________________
Rusting
Example: _________________
Soil Layers Did you know there are three major layers of soil?
Soil develops in a series or horizontal layers called soil horizons.
A soil horizon is a layer of soil with properties that are different from those of the layer above
or below it.
Read page A 124 and 125 in your textbook
1. Draw the three layers of the earth.
2. Label each layer.
3. Write at least two examples of what each layer contains in it or mainly
consists of, using the examples in the horizon paragraphs on A 124.
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1. How does land-use practices in farming, construction and development and mining affect
soil?
2. Describe at least three methods of soil conservation.
ErosionDid you know that human activities put our limited, precious topsoil at a huge risk? In order to
survive, humans have to be able to plant food. If the topsoil disappears or is of poor quality, we
will not be able to grow food at all.
Three reasons why our topsoil is disappearing or going bad is:
 over-farming in the same soil,
 building houses or stores over the land,
 and mining for minerals.
Nature also can harm the soil with what we call “erosion.”
Erosion is the process of carrying away our limited soil through water or wind.
Geography Principals-Soil and Vegetation Discovery Education Video Questions
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Where does the soil come from?
What is the factor of different soil types?
Why is soil so important to humans?
What are soil management techniques called?
What are soil management techniques called?
What are some techniques used to help prevent erosion?
What can farmers do to help the soils nutrients?
Why should we care about soil?