Weathering Flashcards
What are the different types of weathering
Physical, chemical and biological
What is weathering
Weathering is a process whereby rocks and minerals near or at the surface of the earth are broken down into smaller pieces
What is physical weathering
Physical weathering is when rocks are broken down into smaller fragments without any chemical changes
What are the two main types of physical weathering
Freeze-thaw and exfoliation
How does freeze law take place
- Water collects in cracks in rock.
- water freezes and expands
- Ice increases in volume and puts pressure on the rocks, breaking them apart. Then the process repeats, this time the water seeping deeper into the rock
What are the weathering agents in freeze-thaw
Water and temperature
What sort of climate does freeze-thaw tend to happen in
Wet and cold climates
How does exfoliation take place
- Rock surface heats up and expands
- Rock surface cools and contracts
- Joints form in the outer part of the rock
- Small grains of rock break off (granular disintegration)
What are the weathering agents in exfoliation
Temperature
What are the types of chemical weathering
Carbonation, hydrolysis and oxidation
What is carbonation
Rainwater is slightly acidic from carbon dioxide that has dissolved from the air into the rainwater. When it rains minerals in the rock react to the rainwater and it moves through them. This weakens the bond between particles causing weathering
What rocks are easily weathered by carbonation and which are not
Limestone and chalk easily weathered granite is not easily weathered
What is the carbonation formula
H2O (water) + CO2 (calcium carbonate) = H2CO3 (Carbonic acid)
What are the weathering agents of carbonation
Water and carbon dioxide
What is oxidation
This is a type of weathering when iron in rocks react to the oxygen in rain water to produce iron oxide (rust). The oxidized iron in the rock becomes red in color
What are the weathering agents in oxidation
Oxygen and water
What is hydrolysis
It is when rock sits in water for extended periods of time. They start to break down and create a clay like texture.
What are the weathering agents in hydrolysis
Water
What is biological weathering
When animals and plants wear away rock.
Examples of biological weathering
Plants and tree roots grow into small cracks in road, pavements and rocks. Growing roots expand cracks and can split rocks. Animals burrow into cracks breaking rocks down further
What are the different impacts of humans on weathering
Construction, explosives, pollution, biological weathering by walking on paths often, removing of vegetation, burning down of vegetation by farmers, mining, burning fossil fuels causing acid rain
What is the difference between weathering erosion and deposition
Weathering is the breaking down of rocks, soil and minerals. The types of weathering are physical, chemical and biological. Small particles of rock, soil
Erosion is the movement of soil, mud, rock and other particles usually by wind, water or ice. The types of erosion are water, wind, ice or gravity. Landforms are created by the removal of rock and soil particles
Deposition is the laying down of eroded materials, usually by water, wind and ice. The types of deposition are water wind and ice. Land forms are built up by deposited material
What is erosion
The movement of soil,mud,rock and other particles usually by wind water or ice
What is deposition
The laying down of eroded material usually by wind water or ice
What are the types of erosion
Water, wind, ice, gravity
What are the types of deposition
Water, wind, ice
What are the results of weathering
Small particles of rock, soil
What Is the result of erosion
Landforms are created by the removal or rock and soil particles
What is the result of deposition
Landforms are built up by deposited materials
Where does carbonation usually occur
Where there is a lot of pollution and rainfall
Where does oxidation occur
Where there is exposed iron and rain
Where does biological weathering usually occur
Where there are humans, animals and plants that break down rocks
