WED Flash Cards
What is weathering caused by?
Heat, cold, water, ice, carbon dioxide.
What are the two types of weathering? Define them.
Mechanical: a rock is physically broken into smaller pieces.
Chemical: the composition, or make up, of a rock is changed.
What are the types of mechanical weathering?
Freezing and thawing, release of pressure, plant growth, action of animals, abrasion.
Define freezing and thawing.
When water freezes in a crack in a rock, it expands and makes a crack a bigger.
Define release of pressure.
Erosion removes material from the surface of the rock and pressure on the rock is removed. The pressure release causes the outside of the rock to crack and flake off.
Define plant growth.
Roots of trees and other plants enter rock cracks. The roots grow and force cracks farther apart.
Define actions of animals.
Animals that burrow the ground and loosen and break apart rocks in the soil.
Define abrasion.
Sand and other rock particles that are carried by wind, water, or ice wear away exposed rock surfaces.
What are the types of chemical weathering?
Water, oxygen, carbon dioxide, living organisms, acid rain.
Define water weathering.
When a rock or other substance dissolves in water, it mixes throughout the water to make a solution.
Define oxygen weathering.
When iron is left in air/oxygen, a process called oxidation takes place and turns the outer layers of iron into rust.
Define carbon dioxide weathering.
The carbon dioxide that dissolves in rainwater and turns into acid rain.
Define living organisms weathering.
Plants roots grow, produce weak acids that slowly break rocks around the roots. Lichens are plant like organisms that do the same thing.
Define acid rain weathering.
Very rapid chemical weathering caused by sulfur, carbon, and nitrogen compounds that mix with the water vapor, making acids.
Define erosion.
The removal of particles from a location.
