Chapter 12.2 Second period only

1. Weathering, Soil, and Erosion
12.2 Soil

2. Know
✤ soil ✤ soil profile
✤ parent material ✤ soil horizon
✤ residual soil ✤ topsoil
✤ transported soils ✤ subsoil

3. Understand
✤ Soil is made of weathered rock and organic material.
✤ Climate and other factors affect the composition of soils.

4. Do
✤ Explain how soil forms.
✤ Describe soil composition and the factors that affect it.

5. A-horizon
Residual Transported (topsoil)
soil soil B-horizon C-horizon
Parent Profile of
material mature soils
Soil
Arctic Type Desert
Temperate Tropical

7. Name four factors that affect soil
composition.
✤ Time; parent material; topography; climate

9. 12.2 #1. Describe the difference between a
residual soil and a transported soil.
✤ 12.2 #1. Residual soils form from the
bedrock beneath it. Transported soil forms
from parent material that originated in a
different location.

10. #2. Sketch a soil profile and
label A-, B-, and C- horizons.
Describe what you are likely
to find in each horizon.
✤ #2. A-horizon- is likely to
contain humus and sand.
✤ B-horizon is likely to contain
iron oxides, clay and soluble
minerals such as calcium
and magnesium.
✤ C-horizon- is likely to
contain slightly weathered
parent material.

12. #3. What rock materials are found in
soil?
✤ #3. Sand, silt, and clay

14. #4. How does the amount of rainfall appear to affect
whether a soil is a grassland or a forest soil? Explain your
thinking.
✤ #4. It takes more rain to support a forest than
it does to support grassland, thus, forest soil
exists where there is more rain.

15. #5. How do you think the type of soil found in a
particular region might affect the lives of people in
the region?
✤ #5. The type of soil affects how easily
crops can be grown and thus how
large a population can be supported
by local food growth.