Weathering Flashcards
What is mechanical weathering
The breaking down of larger rock into smaller rock
Example of mechanical weathering
Freeze thaw weathering
What is chemical weathering?
A chemical reaction occurs in the rock causing it to devolve and form new substances.
Example of chemical weathering
Limestone dissolves by rainwater forming calcium carbonate in caves.
What is biological weathering?
Disintegration of rocks due to the actions of plants/ animals
What is meant by exfoliation?
it occurs when sheets or layers of rock split off due to thermal expansion and contraction of minerals.
Explain freeze thaw weathering
Water expands when it freezes and exerts a mechanical force on the rocks surrounding it.
what is root action?
causes the mechanical and chemical weathering of rocks by the wedging action of a plant roots that may grow along joints and bedding planes.
What is burrowing?
Burrowing mixes and brings rock and soil particles to the surface. This facilitates chemical weathering at greater depth, as the burrows can be accessed by atmospheric gas and water.
How does chemical weathering work?
Rocks decompose when the chemical structure of their minerals breaks down.
What do chemical weathering reactions produce?
All chemical weathering reactions involve water and produce ions that are removed in solution, leaving an insoluble residue, usually clay minerals.