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Name:______Date:______Pd:______
Standard S6E5 d., h., f., and j. Assessment Review
1. Define weathering.. / The process by which rock materials are broken down into sediment by the action of physical or chemical means2. Define mechanical weathering.
What are the agents of mechanical weathering? / The breakdown of rock into smaller pieces (sediments) by physical means- wind, water, gravity, plants, animals, glaciers (Ice
3. Define abrasion.
Weathering by abrasion is caused by…. / Abrasion the grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles
Wind, Water, and Gravity
4. Define ice-wedging (mechanical weathering)
Create an illustration ice-wedging / Starts when water seeps into cracks during warm weather. When temperatures drop, the water freezes and expands-the ice then pushes against the crack, this causes the crack to widen
5. What happens to water when it freezes? / It expands and become less dense
6. Define chemical weathering.
What are the agents of chemical weathering? / The process by which rocks break down as a result of chemical reactions-the chemical bonds that hold the rock together breakdown (acids and dissolves)
Agents- weak acid (acids in water and acids in living things), air(oxygen reacting with iron) –oxidation increase in warm and humid (wet) environments
7. When oxygen reacts with iron in rock it causes the rock to …….
This process is called …… / Rust (iron oxide)
Oxidation –chemical weathering process
8. Chemical weathering is most rapid in areas that are______and ______. / Warm and Humid (wet/water vapor)
9. Describe acid precipitation. What is the main cause of acid precipitation? / Rain, sleet, or snow, that contains a high concentration of acids- due to the burning of fossil fuels/pollution
10. Describe how acids in living things chemically weather rock. Give examples of living things that chemically weather rock. / Lichens and mosses produce weak acids that can slowly break down rock
Examples-Lichens and Mosses
11. What is biological weathering? / Living things (plants and animals) that break rock apart physically and chemically
12. What is differential weathering? / The process by which softer, less weather resistant rocks wear away and leaves harder, more weather resistant rocks behind-Ex. Devil’s Tower
13. Describe how surface area affects the rate of weathering of rocks. / When the surface area of a rock is increased it causes the rock to weather faster
Increase in surface area=an increase in the rate of weathering
If you break a rock into more pieces you increase the surface area of the rock
Smaller rocks with the same volume will weather faster than a larger rock with equal volume
14. How are the peaks of mountains and the edges of rocks affected by the weathering process? / The mountain peaks are rounded off and the edges of rocks become smooth over time
15. Describe the process of erosion. / The process by which wind, water, glaciers, or gravity transport (move) soil and sediment from one place to another
16. What can be done to reduce the effects of erosion on steep slopes? /
- Plant vegetation on the slope
- Don’t remove trees and vegetation on a slope
- Create terraces on the slope (stair-steps)
17. Describe how the following agents cause erosion
Moving water (rivers), wind, glaciers, waves, and gravity / Water-This agent is considered the main agent of erosion and moves an enormous amount of weathered rock and soil creating some of the most impressive landforms on Earth
Wind-This agent causes erosion by lifting weathered rock particles and blowing them away. These small particles can be carried miles before they are dropped. It also smashes sand against rock surfaces to cause weathering.
Glaciers-This agent erode rock and soil as they grind slowly over Earth's surface. They can form U-Shaped valleys. This agent is an enormous mass of moving ice.
Ocean Waves-This agent of erosion and deposition pounds against the shoreline braking rock apart creating sand. It deposits sand to form beaches. It also moves or erodes sand away from beaches.
Gravity-This agent of erosion moves weathered rock and soil down a slope.
18. Compare and Contrast Deltas and Alluvial Fans / Delta- fan-shaped deposit (landform) that forms when a river empties into an ocean, gulf, or lake
Alluvial Fan- fan-shaped deposit (landform) that forms when a rivers empties into a flat open plain (forms on dry land)
19. Describe the process of deposition. / is the process in which weathered rock and soil are laid down or dropped by wind, water, glaciers, or gravity and landforms are created
20. Describe the landforms that are created when agents of erosion drop the sediments they are carrying (process of deposition). (wind, moving water, gravity, glaciers, and waves) / Rivers (moving water)- Delta and Alluvial Fan
Gravity- Landslide (slump), Rock Fall, Mudflow, Creep
Glaciers- Moraine and Till
Ocean Waves- Beaches, Barrier Island, Sandbar
Wind- Sand Dune and Loess Deposits
21. Define soil / Soil is a mixture of rock particles, minerals (44%), decayed organic material (6%), air(25%) and water (25%)
22. Describe how soil forms? / Soil forms as rock is broken down by weathering and mixes with other materials on the surface of the earth
23. Humus found in soil comes from… / Decayed plants and animal matter (decomposers in the soil- bacteria, fungi, worms etc.)
24. What type of soil is best for plant growth? Why? / Loam is the best type of soil for plant growth.
Contain equal parts of sand, silt, and clay (soil particles), organic matter, air, and water
Impermeable –not allowing water to pass through
25. What happens to soil when it loses it nutrients?
What is leaching? / When soil loses its nutrients it becomes infertile-plants can not grow in the soil
Leaching is removal of nutrients and other substances from the soil when water passes through it
26. Why is soil considered a nonrenewable resource? / Because it takes thousands of years to form-to get to the point where it can support a lot of vegetation and homes for many organisms
27. What is soil conservation?
Describe the benefits that soil provides. / The method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss (Saving Soil)
Provides minerals and nutrients for plants
Allows for water storage for plants
Provides a habitat for animals
Place to grow crops (food and other raw materials)
28. Draw a model of the soil profile. Label each horizon and write a description for each.
In which layer would you find the parent rock? (D Horizon) / Soil Profile
A Horizon- Topsoil, litter, humus, vegetation, dark colored soil, organisms
B Horizon-Subsoil, clays, silt, some plant roots-light in color
C Horizon-partially weathered rock
D Horizon- Bedrock-solid rock
29. On a separate sheet of paper explain the following soil conservation techniques, be sure to include in your explanation if the technique prevents nutrient loss, soil erosion, or both:
- No-till farming
- Contour plowing
- Crop rotation
- Terracing
- Cover crop
- Windbreaks
No-till farming-leaving stalks on the ground provides cover during heavy rains (decomposed stalks add nutrients back to the soil)
Contour Plowing
Contour Plowing-plowing across the slope of a hill, the crops act like series of dams to slow down erosion of soil from heavy rains
Terracing
Terracing- technique used on steep slopes look like stair steps- to prevent erosion from heavy rains
Crop Rotation
Crop Rotation- slow down nutrient depletion not planting the same crop year after year-plant different crops
Cover Crop
Cover Crop- Examples are soybeans and peanuts, these crops are planted between harvest seasons to replace certain nutrients and provide cover for the soil to prevent erosion
Windbreaks
Windbreaks-Rows of large trees or bushes planted between fields to help block the wind and prevent soil erosion.