Weathering and Soil Formation
Name __________________________________
Earth Science Study Guide
Date ___________________________________
All answers should be found in workbook or IAN (interactive notebook).
1. Know the following terms: (most are included in the crossword)
Weathering, erosion, mechanical weathering, abrasion, ice wedging, chemical weathering, oxidation,
acid rain, permeable, bedrock, humus, soil, fertility, loam, soil horizon, topsoil, subsoil, litter,
decomposers, sod, natural resource, Dust Bowl, soil conservation, contour plowing, conservation
plowing, crop rotation
2. What is the difference between weathering and erosion? Weathering is the breaking down or
rock and erosion is the movement of rock particles
3. 5 causes of mechanical weathering Abrasion, plant growth, release of pressure, animal actions,
ice wedging/freezing and thawing
4. 5 causes of chemical weathering Water, oxygen, carbon dioxide, living organisms, acid rain
5. Factors that affect the rate of weathering—in which type of climate would you expect to find
more weathering? Which rock weathers faster? Climate and type of rock; wet and warm/hot
climate would have more weathering; marble weathers faster than granite
6. 5 components of soil Rock particles, minerals, decayed organic material, water and air
7. How does soil form? Which layer forms first? Which layer forms next? Which layer forms last?
When rock is exposed, it can be weathered; weathered bedrock is the first step—this is horizon
C; then seeds get dropped between the sediment and begin to sprout; over time these plants
decay and return their nutrients to the soil, creating the topsoil, or horizon A; after years of
more and more topsoil, the subsoil is formed as clay and other particles are washed down from
the topsoil—this is horizon B
8. How do scientists classify the type of soil? Climate, type of plants, and soil composition
9. What soil type is where we live? Be able to recognize other soil types. Southern forest soil;
tundra, mountain, prairie, desert
10. What is the role of living organisms in the soil? Some burrow and make spaces for air and water;
others mix the soil; and decomposers break down the organic matter to return nutrients to the
soil
11. List some organisms involved in the formation of soil. Earthworms, chipmunks, mice, bacteria,
fungi, insects, plant roots, leaves and stems…
12. Why is soil a natural resource? All living things depend on it for survival
13. How does soil lose its fertility? By planting too much of the same crop, depleting (or using up)
the soil’s nutrients
14. Who was George Washington Carver? Scientist who worked with farmers and promoted soil
conservation (he also encouraged them to grow peanuts to replenish the nutrients in the soil—
he experimented with peanuts and other crops to find many uses for the farmers’ crops)
15. What happened during the Dust Bowl? Plants had been plowed, exposing the soil; drought dried
it up, and wind storms blew it away—it taught us the value of conserving the soil
16. What are three methods of soil conservation?
Crop rotation—planting different crops in a field each year
Contour plowing—plowing fields along the curves of a slope
Conservation plowing—leaving dead plants in fields to conserve soil (disturbing the soil as little
as possible)