Weathering
What does weathering do to rocks?
It chemically or physically breaks them down
How is gravity related to erosion?
gravity pulls all things downhill. (water, glaciers, landslides)
What is the difference between residual and transported soil?
Residual soil forms from the bedrock below it and stays there. Transported soil has been eroded away and deposited somewhere else.
What soil texture is best for growing crops?
Loam
Are waves a destructive force(erode), constructive force(deposit), or both?
Both. Waves can erode cliffs and wash away sea floors, and they can build beaches, sand bars, and barrier islands.
Give 1 example of physical weathering.
Examples could include: frost wedging, root pry, exfoliation
How is erosion different from weathering?
Weathering breaks the rocks down. Erosion carries those particles from one place to another.
Name at least 3 factors that affect soil formation.
Amount of rainfall
Temperature
Type of bedrock
Presence of vegetation
Topography
What are the components that tell us the texture of a soil, in order from largest to smallest?
Sand
Silt
Clay
Give 1 example of chemical weathering.
Examples could include: Oxidation, water dissolving rocks, acid rain.
How does carbon dioxide contribute to chemical weathering?
Carbon dioxide combines with water to form carbonic acid. This can rain down and help dissolve rocks.
What is the difference between rill and gully erosion?
Rill erosion occurs when water forms small channels in the soil. Gully erosion is much larger than rill. It occurs if rill erosion is left unchecked.
What soil horizon has a mostly clay texture?
B Horizon
Is it possible to have a soil texture with 50% sand, 50% silt, and 50% clay?
No, (50+50+50=150) we cannot have 150% of something. All percentages of soil particles must add up to 100.
When engraving an outdoor monument in Dubuque, which material will last longer? Granite or Marble?
Granite. It will not weather as easily as marble.
Daily Double:
1. What is the relationship between weathering and surface area?
2. Which has more surface area, a large rock or a pile of gravel with the same mass?
1. more surface area=more weathering
2. the pile of gravel
How is a delta formed?
A river slows down as it reaches an ocean. The slow water can now drop sediments to the bottom. over time, a triangular shaped deposition area forms called a delta.
Daily Double:
1. What are the 4 horizons in a soil profile?
2. Which one contains decomposing plant matter?
1. O, A, B, C
2. The O horizon contains decaying humus and leaf litter
What is the soil texture of a sample of soil containing 50% sand, 10% silt, and 40% clay?
Sandy clay
Daily Double:
1. What are the major components of acid rain?
2. Where do they come from?
1. Sulfur dioxide, nitrogen oxides, and carbon dioxide
2. Burning fossil fuels
What climate does chemical weathering most easily occur?
What climate does physical weathering most easily occur?
(looking for hot/cold, wet/dry)
Chemical: warm, rainy climate
physical: cold climate
What type of environment would wind be the largest factor affecting erosion?
Low precipitation and hot temperatures (desert/dry environment)
What are the 3 steps in the formation of soil?
1. Weathering breaks bedrock into smaller pieces
2. organisms begin to live in the weathered materials
3. organisms die, decay, and add organic matter to the soil
What is the highest percentage of silt that can be in a loam soil texture?
50%
1) Why is soil fertility important?
2) Describe 1 threat to the future soil fertility of Iowa. Explain in detail.
1) Soil fertility is the ability of soil to grow plants. Without fertility, we could not easily grow food.
2) Many answers, need detailed explanation