Name:
Period:
Date:
Background: Weathering includes both mechanical and chemical weathering. Mechanical weathering is any
process that breaks up rock without changing its chemical composition. Chemical weathering is any process in
which water, air or other substances react with the minerals in the rock and change the chemical composition.
Directions: Decide if the weathering process is mechanical (M), chemical (C) or both (B). Then, indicate the
type of weathering (agent of weathering). Question #1 has been completed for you as an example.
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____________ 1. Lichen growing on the surface of rocks, producing pits in the rocks.
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____________ 2. The wedging of tree roots along cracks in granite outcrops.
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____________ 3. Limestone dissolved away producing an underground cave.
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____________ 4. Minerals that contain iron turn yellowish brown indicating the formation
of rust.
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____________ 5. This type of weathering includes repeated freezing and thawing of water that cracks
rocks.
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____________ 6. Water, salt and oxygen on car fenders and panels is this type of weathering.
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____________ 7. Rocks that have been carried by streams and have become smaller and
more rounded.
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____________ 8. Feldspar mixed with water until it dissolves, producing clay minerals.
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____________ 9. A boulder field is created at the base of Pike’s Peak.
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____________ 10. Independence Rock in Wyoming, Half dome in Yosemite, and granite outcrops
in Central Minnesota all show signs of weathering because the outer parts of
the rock are peeling off in layers.
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____________ 11. Sulfur dioxide and nitric oxide are formed as a result of burning fossil fuels.
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____________ 12. A large piece of basalt has a pine tree growing through it.
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____________ 13. Rocks crack because of repeated expansion and contraction.
Part I. Complete the chart below
Cause/Specific type of
Weathering
Kind of Weathering
Description
1. _____________________
Mechanical
Rock particles carried by wind and
water wear away rock
2. _____________________
Chemical
Freezing and thawing
Carbon dioxide
5. ______________________
6. ______________________
Plant growth
3. ______________________
4. ______________________
Plants produce this as they grow
causing minerals in rocks to decay
Breaks rock by wedging rocks
apart
Combines with water in the
atmosphere to form carbonic acid
Weathers marble and limestone
Chemical
Mechanical
Causes movements such as
landslides that further break down
rocks
Roots pry apart cracks in rocks
7. ______________________
Combines with iron to produce rust
Oxygen
9. _______________________
8. _______________________
Chemical
Formed in factories and cars an a
result of burning fossil
fuels—creates acid rain
Part II. Completion
1. How are chemical and mechanical weathering alike?
2. How are chemical and mechanical weathering different?
Part III. Matching
3. _____water
a. This gas, when mixed with water, causes iron to rust
4. _____oxygen
b. This is caused by pollution
5. _____carbon dioxide
c. It is the most important factor in several types of weathering
6. _____living organisms
d. This is the main “ingredient” in making carbonic acid
7. _____acid rain
e. Lichens are one example of …...