5.1 #1-6 Use as much space as needed. Be sure to save before the bell.
1. What is mechanical weathering? Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks. The rocks are essentially torn apart by physical force, rather than by chemical breakdown.
Mechanical Weathering
The forces that break rocks down can be numerous, and include such things as pent up energy as the Earth’s crust slowly moves. When great amounts of pressure build up, the resulting mechanical effect can be that very large joints, or faults are created.
2. What are the three physical processes that make up mechanical weathering? Give an example of EACH.
a. Abrasion is the grinding action of other rock particles due to gravity or the motion of water, ice or air.
b. Crystallization of ice (frost shattering) or certain minerals such as salt (as in the formation of tafoni) can exert enough force to fracture rock.
c. Thermal fracture is the result of rapid temperature change, as by fire, volcanic activity or day-night cycles (as in the formation of grus), all of which rely on the differences in thermal expansion among a mixture of minerals.
d. Hydration shattering may strongly affect clay minerals, which swell with the addition of water and force openings apart.
e. Exfoliation or pressure release jointing results from the stress changes as rock is uncovered after its formation in deep settings.
3. What is chemical weathering? Chemical weathering takes place in almost all types of rocks. Smaller rocks are more susceptible however, because they have a greater amount of surface area.
Chemical Weathering
Chemical reactions break down the bonds holding the rocks together, causing them to fall apart, forming smaller and smaller pieces. Chemical weathering is much more common in locations where there is a lot of water. This is because water is important to many of the chemical reactions that can take place. Warmer temperatures are also more friendly to chemical weathering. The most common types of chemical weathering are oxidation, hydrolysis and carbonation.
4. What is the most important agent of chemical weathering?
Water.
5. Discuss briefly weathering of Granite, Silicate Minerals and Spheroidal Weathering. Weathering of potassium feldspar produces clay minerals, soluble salt (potassium bicarbonate), and silica in solution. Produces insoluble iron oxides and clay minerals. Causes the corners and edges of rock to be more rounded.
6. What are two factors that affect the rate of weathering? rock characteristics and climate.
5.2 #7-15
7. What are the four components of soil?
a. mineral matter, or broken-down rock
b. humus, which is the decayed remains of organisms
c. water
d. air.
8. What are the most important factors in soil formation? Parent material, time, climate, organisms, and slope.
9. What is the difference between residual soil and transported soil?
Residual is in bedrock and Transported from somewhere else.
10. What type of soil consists of 10% clay, 60% silt, and 30% sand?
Silty loam.
11. Explain how the slope of the land affects soil thickness. Orientation, or direction the slope is facing, influences soil formation.
12. What are the three soil horizons?
a. topsoil
b. subsoil
c. bedrock/rock
13. What are the 3 types of soil? Name and describe each and where they are found.
a. Pedalfer- Accumulation of iron oxides and aluminum-rich clays in the B horizon
b. Pedocal- Accumulates calcium carbonate.
c. Laterite- Intense chemical weather.
13. Based on what you have read about clearing tropical rain forests, what can be done to the Colombian field to reduce soil erosion? Planting trees so the roots keep the soil in place.
14. How do human activities effect erosion? Human activities that remove natural vegetation, such as farming, logging, and construction, have greatly accelerated erosion.
15. Which activity would cause more sediment to be deposited in a river that flows through a gently sloping valley----cultivating the valley or cultivating the hills that surround the valley? EXPLAIN..
The hills that surround the valley, because the water is going to be hitting the slope and sliding down the slope.
5.3 #16-20
16. What is mass movement?
The movement of rock and soil downslope due to gravity.
17. What factors trigger mass movement? Saturation of surface materials with water, oversteepening of slopes, removal of vegetation, and earthquakes.
18. How do geologists classify mass movements? The kind of material that moves.
19. What are the TYPES of mass movement?
Rockfalls, Slides, Slumps, Flows and Creeps
20. How does a rock slide differ from a mass movement? Rock slides have bedrock.
5.1 #1-6 Use as much space as needed. Be sure to save before the bell.
1. What is mechanical weathering?
Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks. The rocks are essentially torn apart by physical force, rather than by chemical breakdown.
The forces that break rocks down can be numerous, and include such things as pent up energy as the Earth’s crust slowly moves. When great amounts of pressure build up, the resulting mechanical effect can be that very large joints, or faults are created.
2. What are the three physical processes that make up mechanical weathering? Give an example of EACH.
a. Abrasion is the grinding action of other rock particles due to gravity or the motion of water, ice or air.
b. Crystallization of ice (frost shattering) or certain minerals such as salt (as in the formation of tafoni) can exert enough force to fracture rock.
c. Thermal fracture is the result of rapid temperature change, as by fire, volcanic activity or day-night cycles (as in the formation of grus), all of which rely on the differences in thermal expansion among a mixture of minerals.
d. Hydration shattering may strongly affect clay minerals, which swell with the addition of water and force openings apart.
e. Exfoliation or pressure release jointing results from the stress changes as rock is uncovered after its formation in deep settings.
3. What is chemical weathering?
Chemical weathering takes place in almost all types of rocks. Smaller rocks are more susceptible however, because they have a greater amount of surface area.
4. What is the most important agent of chemical weathering?
Water.
5. Discuss briefly weathering of Granite, Silicate Minerals and Spheroidal Weathering.
Weathering of potassium feldspar produces clay minerals, soluble salt (potassium bicarbonate), and silica in solution. Produces insoluble iron oxides and clay minerals. Causes the corners and edges of rock to be more rounded.
6. What are two factors that affect the rate of weathering?
rock characteristics and climate.
5.2 #7-15
7. What are the four components of soil?
a. mineral matter, or broken-down rock
b. humus, which is the decayed remains of organisms
c. water
d. air.
8. What are the most important factors in soil formation?
Parent material, time, climate, organisms, and slope.
9. What is the difference between residual soil and transported soil?
Residual is in bedrock and Transported from somewhere else.
10. What type of soil consists of 10% clay, 60% silt, and 30% sand?
Silty loam.
11. Explain how the slope of the land affects soil thickness.
Orientation, or direction the slope is facing,
influences soil formation.
12. What are the three soil horizons?
a. topsoil
b. subsoil
c. bedrock/rock
13. What are the 3 types of soil? Name and describe each and where they are found.
a. Pedalfer- Accumulation of iron oxides and aluminum-rich clays in the B horizon
b. Pedocal- Accumulates calcium carbonate.
c. Laterite- Intense chemical weather.
13. Based on what you have read about clearing tropical rain forests, what can be done to the Colombian field to reduce soil erosion? Planting trees so the roots keep the soil in place.
14. How do human activities effect erosion?
Human activities that remove natural vegetation, such as farming, logging, and construction, have greatly accelerated erosion.
15. Which activity would cause more sediment to be deposited in a river that flows through a gently sloping valley----cultivating the valley or cultivating the hills that surround the valley? EXPLAIN..
The hills that surround the valley, because the water is going to be hitting the slope and sliding down the slope.
5.3 #16-20
16. What is mass movement?
The movement of rock and soil downslope due to gravity.
17. What factors trigger mass movement?
Saturation of surface materials with water, oversteepening of slopes, removal of vegetation, and earthquakes.
18. How do geologists classify mass movements? The kind of material that moves.
19. What are the TYPES of mass movement?
Rockfalls, Slides, Slumps, Flows and Creeps
20. How does a rock slide differ from a mass movement? Rock slides have bedrock.