Name:______KEY______Date:______Pd:______
Standard S6E5 d. h. and j. Assessment Review
1.Define abrasion.Weathering by abrasion is caused by…… / The action of rocks & sediment grinding against each other wearing away exposed surfaces.
Wind, water & gravity
2.When oxygen reacts with iron in rock it causes the rock to ……
This process is called…. / rust
oxidation
3.On a separate sheet of paper draw a model of the soil profile. Label each horizon and write a characteristic for each horizon. / Horizon A – Topsoil (contains the most humus)
Horizon B – Subsoil (where clays and dissolved substances collect
Horizon C – Partially Weathered Bedrock
Horizon D – Bedrock (parent rock) where leached materials collect
4. Humus found in soil comes from……. / Decaying Plants & animals
5. Chemical weathering is most rapid in areas that are ______and ______/ Warm and wet/humid
6.Define Ice wedging / Process in which water freezes and widens cracks in rock.
7. What happens to water when it freezes? / It expands.
8. Describe acid precipitation / Rain, sleet, snow with a high concentration of acid (chemical weathering)
9. Define weathering / When rock materials are broken down by the action of physical or chemical processes
10. Define chemical weathering and its agents / Process that breaks down rocks as a result of chemical reactions
Agents: water, weak acids, air
11. Define mechanical weathering and it agents / The breakdown of rock into smaller pieces by physical means.
Agents: ice, wind, water, gravity, plants (roots) & animals.
12. What is the main cause of acid precipitation? / The burning of fossil fuels.
13. Describe how acids in living things chemically weather rock. Give examples of living things that chemically weather rock. / Living things sometimes produce acids that can slowly break down rock.
Lichens (algae & fungus living together) do this.
14. What is differential weathering? / Softer, less weather-resistant rocks wear away leaving harder, more weather resistant rock behind. (Devil’s Tower in Wyoming)
15. Describe how surface area affects the rate of weathering? / Increasing the surface area increases the rate (speed) of weathering.
16. In which horizon would you find the parent rock? / Horizon D
17. What happens to soil when it loses it nutrients? What is leaching? / Plants are unable to grow in it.
Nutrients and minerals are washed-out or seep deeper into the earth.
18. What are the benefits that soil provides? / Nutrients for plants, storage for water, and homes for animals. We need plants and animals for our food so good soil = more food for us too
19. Describe cover crops and its advantages for conserving soil and increasing soil fertility. / They reduce soil erosion by wind and water. Soybeans are low to the ground and offer protection from wind/water and keep nutrients from washing away.
20. What type of soil is best for plant growth? Why? / Loam – Equal mixture of sand, silt & clay. Allows for the infiltration of water and air and to be broken up for farming. The best soil for growing crops
22. When soil is unprotected, it can be exposed to ______and ______, which causes erosion / Wind & water
23. What is soil conservation? / Keeping the fertility of the soil by protecting it from erosion and nutrient loss.
24. Describe how soil forms? / The parent rock determines what soil forms. Rocks weather at a slow rate, become mixed with plant and animal material (humus).
25. Define soil / A loose mixture of small mineral fragments and organic material.
26. Why is soil considered a nonrenewable resource? / It forms at a very slow rate.
25. On a separate sheet of paper explain the following soil conservation techniques, be sure to include in your explanation if techniques prevents nutrient loss, soil erosion, or both:
- No-till farming
- Contour plowing
- Crop rotation
- Terracing
- Cover crop
Contour plowing: plowing across the slope of a hill prevents soil erosion
Crop rotation: alternate crops planted in an area to slow down nutrient (loss) depletion
Terracing: changes a steep field into several smaller fields to prevent water erosion
Cover crop: crops planted between harvests to replace nutrients and prevent erosion