Chapter 6: Weathering, Soil and Erosion Flashcards
1
Q
Regolith
A
loose material at the Earth’s surface
2
Q
Soil
A
regolith produced in place by weathering
3
Q
Sediment
A
regolith transported and deposited
4
Q
Mechanical Weathering
A
Disintegration:
- Frost wedging:pressure
- Unloading: sheet joints, pressure release
- Salt weathering: pressure
- Clay expansion: pressure
5
Q
Chemical Weathering
A
Decompostion: forms new secondary minerals and dissolved ions that are deposited in soil or removed in solution (leached)
- Oxidation of iron produces hematite (rust)
- Hydrolysis: reaction of water w/ mineral
6
Q
Solution
A
calcite+water+CO2 yields dissolved Ca and bicarbonate
7
Q
O-Horizon
A
plant litter, dark gray (no rocks/minerals)
8
Q
A-Horizon
A
decaying organic and mineral matter, leached, dark gray
9
Q
E-Horizon
A
mineral and no organic matter, leached, light color
10
Q
B-Horizon
A
accumulation, secondary minerals deposited by soil water
- Chemical precipitates: calcite (white, dry climate), iron and aluminum oxides (reddish brown, humid climates)
- Clay minerals
11
Q
C-Horizon:
A
oxidized parent material
12
Q
R-Horizon
A
bedrock parent material
13
Q
Soil Erosion
A
Removal of loose minerals
- Sheet flow(Sheet erosion) and rills
- Land use: soil conservation practices
