Formation Flashcards
Soil formation
1
Q
Factors affecting soil development ?
A
Parent Material Climate Living Organisms Topography Time
2
Q
Mechanical weathering types ?
A
- Temperature Change
- Wedge action of ice
- Spreading of roots
- Abrasion
3
Q
Mechanical - Temperature Change
A
- Minerals have different coefficient of thermal expansion.
- Unequal expansion and contraction due to temperature change.
- Induced stresses cause particle detachment.
4
Q
Mechanical - Wedge action of Ice
A
- Pores of rocks frozen.
- Volume of ice > volume of water.
- Large stresses form cracks due to wedging.
5
Q
Mechanical - Spreading of roots
A
- Roots grow into cracks and fissures.
- Forces act on rock.
- Segments forced apart.
6
Q
Mechanical - Abrasion
A
- Water, wind , glaciers move over rock surface.
2. Abrasion and scouring occur.
7
Q
Chemical weathering types ?
A
- Hydration
- Carbonation
- Oxidation
- Solution
- Hydrolysis
8
Q
Chemical - Hydration
A
Water combines with minerals to form a new chemical compound.
9
Q
Chemical - Carbonation
A
- Carbon dioxide in air reacts with rain.
- Carbonic acid formed.
- Carbonic acid reacts chemically with rocks.
10
Q
Chemical - Oxidation
A
Oxygen ions react combine with minerals
11
Q
Chemical - Solution
A
Rocks dissolve in water
12
Q
Chemical - hydrolysis
A
- Water to H and OH
- H replace metallic ions
- New chemical composition
13
Q
Biological Weathering
A
Bacteria and other microorganisms
14
Q
Residual and transported soil
A
Residual: Soil remains at place of formation.
Transported: Deposited away from origin.
15
Q
Water (Alluvial) deposits
A
Lacustrine: deposits in lakes.
Marine: flowing water carries soils to ocean/sea.
