3.2 Weathering Flashcards
What is weathering?
The breakdown of rocks by the elements of the weather in exception for wind
What are the two types of weathering?
Physical and Chemical
What is physical weathering?
The breakdown of rocks into smaller fragments
What are the 5 types of physical weathering?
- Freeze-Thaw
- Exfoliation
- Salt Crystallisation
- Pressure Release
- Tree roots
What is freeze-thaw weathering?
Water enters cracks/joints and then expand when it freezes then repeats as it goes back above 0 degrees
What is exfoliation weathering?
Rock expanding when heated and contracting when cooled, the outer layer cracks as it receives more heat than the inner layer
What is salt crystallisation weathering?
Solutions of salt can get into the pores and the salts precipitate, growing crystals which these expand
What is pressure release weathering?
Overlying rocks is removed by erosion the underlying rock expands
What is tree root weathering?
Tree roots grow into the cracks/joints of a rock and exert outwards pressure
What is chemical weathering?
Chemical reactions between elements of the weather and mineral within the rock
What are the 6 types of chemical weathering?
- Carbonation
- Hydration
- Oxidation
- Solution
- Hydrolysis
- Organic Acids
What is carbonation weathering?
Carbonic acid being created which reacts with calcium carbonate in rocks and they dissolve
What is hydration weathering?
Water molecules added to minerals in rocks, causing chemical reactions
What is oxidation weathering?
Some minerals in rocks such as iron based minerals react with oxygen in the air
What is solution weathering?
Some minerals dissolve in water overtime due to the lower PH
What is hydrolysis weathering?
Chemical reactions between rock minerals and water such as formation of clay
What is organic acid weathering?
Organic acids which are formed by the decomposition of litter which causes soil water to become more acidic and react with minerals
What are the main type of factors that effect weathering?
Climate, Geology, Relief, Vegetation and human activity
How does higher temperature effect climate weathering?
Faster Chemical Reactions
How does higher precipitation effect climate weathering?
Dead leaves release more organic acids
How does a temperature around 0 degrees effect climate weathering?
Freeze Thaw Occurs
How does more moisture effect climate weathering?
More chemical reactions
How does a larger diurnal range effect climate weathering?
More exfoliation
How does more pores effect geological weathering?
Water gets inside the rock more often
