Download Weathering and Erosion study guide

1. What is mechanical weathering?
a. The breakdown of rock into smaller pieces by physical means.
2. Name and describe the 5 ways in which mechanical weathering can occur.
a. Ice-freezing and thawing of soil and rock
b. Water-carries rocks and pebbles along streams and they hit other rocks breaking them
apart
c. Wind-carries sand and beats against rocks
d. Gravity-pulls rocks down on one another
e. Plants-roots go into cracks in rocks
f. Animals-burrow in soil
3. What type of mechanical weathering can cause large cracks in rocks?
a. Plants and Ice
4. What is chemical weathering?
a. Rocks break down as a result of a chemical reaction
5. Name and describe 3 ways in which chemical weathering can occur.
a. Water-dissolves rock
b. Air-reacts with iron and water to form rust
c. Acid Rain-the acid eats away at the rock
6. What is erosion?
a. The process by which wind, water, ice, or gravity transport soil and sediment from one
location to another
7. What is deposition?
a. The process in which material is laid down
8. How does a river valley form?
a. Weathering and erosion
9. What is a landslide?
a. The sudden movement of rock and soil down a slope
10. How quickly does weathering usually take place?
a. Very slowly
11. How are canyons formed?
a. By erosion from water
12. What is a delta and how is it formed?
a. A fan-shaped mass of material deposited at the mouth of a stream by erosion
13. How do mountains look after they have been weathered for many centuries?
a. Smooth and worn down
14. What is soil composed of?
a. A loose mixture of rock fragments, organic material, water, and air that can support the
growth of vegetation
15. What happens to plants after they die?
a. They decompose and become soil
16. What is humus and what is it made of?
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a. The dark, organic material formed in soil from the decayed remains of plants and
animals
What layer of soil is humus usually located in?
a. Topsoil
As a result of drought and farm animals over-grazing what might happen to soil?
a. Erosion by wind or water
How can farmers prevent soil erosion?
a. Terracing, Cover crops, No-till farming, Contour plowing
What are some ways to conserve water?
a. Turn the faucet off when brushing your teeth, put rain barrels outside to collect water,
wash dishes only when the dishwasher is full, etc.