TOPIC 4 OBJECTIVES
SURFACE PROCESSES
1. a. Define physical weathering.
When rocks are broken into smaller pieces
b. Define chemical weathering.
When a rock is changed by either adding or removing elements by a chemical reaction.
2. Describe the effect of climate on weathering.
For frost action to take place you need a climate that has moisture and the temperature that goes above and below freezing frequently. Plant action is dependent on having enough moisture and high enough temperatures for plants to grow. Chemical weathering is dominant in hot, wet areas.
3. Describe the relationship between weathering and particle size.
As the particle size decreases the weathering rate increases.
4. Explain the effect of mineral composition on the rate of weathering.
The closer the mineral formed to the conditions found on the surface of the Earth, low temperature and low pressure, the slower it will weather.
5. a. List the two major components of soil.
1. Weathered rock.
2. Organic material, which is called humus.
b. Describe two processes that result in the formation of soil.
1. All of the processes that weather rock.
2. Biological activity.
6. Account for different types of soil forming from similar types of bedrock.
The key is the climate of the areas. If the climate promotes life it will produce a soil very different from an area which does not.
7. Describe the steps leading from an immature soil to a mature soil.
Areas begin as solid rock. Over time the agents of weathering will begin to break the rock into pieces. Eventually biological activity will weather the rock further and add organic material to the soil.
8. Determine the positive and negative effects that humans have on soil.
Negative:
Removing vegetation promotes erosion.
Pollution.
Destruction of rain forest destroys soil.
Strip mining.
Positives:
9. Distinguish between transported and residual material.
A Transported Soil is made from material that was moved to an area by an agent of erosion. Most of New York State is covered by transported soils. The agents of erosion were glaciers.
A Residual Soil is made from the bedrock in the area.
10. Define erosion.
This is the movement of Earth's materials.
11. Name the primary force of erosion.
The primary force of erosion is gravity.
12. Name the primary agent of erosion.
The primary agent of erosion is running water.
13. Describe the effects that volume and gradient have on the velocity of a stream.
As the volume, or amount, of water in a stream increases the velocity of the stream increases.
As the gradient, or slope, increases the velocity of the stream increases.
14. Given either a cross-section or top view of a stream, determine the location of greatest velocity and erosion.
STRAIGHT STREAM
In a side view the water will be the fastest just below the surface in the meddle of the stream
CURVED STREAM
15. Using the Earth Science Reference Tables (ESRT), determine the size of particle, which can be moved by certain stream velocities.
The chart is on page 6 of the ESRT.*Page 6 ESRT* An example of the type of problem the students might have to do is: A particle that has a diameter of 6.4 cm would need a velocity of __________ to be moved by a stream. The answer is 200 cm/sec.
16. List four methods by which streams carry sediment.
1. Solution: This is when a material is dissolved in water.
2. Suspension: This is when very small particles are kept off of the bottom of a stream by currents in the water.
3. Saltation: This is when larger particles, for example sand, bounce off of the bottom of a stream.
4. Traction: This method of transport is for the largest particles the stream can transport. In this method the particles never loose contact with the bottom of the stream.
17. Describe the effect that shape, size, and density of a particle has on the rate of deposition.
Shape: The more spherical the particle the faster it will settle.
Size: The larger the particle the faster it will settle.
Density: The greater the density the faster it will settle.
18. Compare and contrast the characteristics of sediment deposited by various agents of erosion.
WATER:
WIND:
GLACIERS:
19. a. Construct a diagram showing vertical sorting.
If using size as the distinguishing feature of the particles, vertical sorting would look like the diagram below.
b. Construct a diagram showing horizontal sorting.
Horizontal sorting looks like the diagram below.
HORIZONTAL
SORTING LOOKS LIKE THIS