Weathering/erosion Review Flashcards
Define erosion
The removal of rock particles by wind water ice or gravity
Define weathering
The process that breaks down rock and other substances at earths surface
Define mechanical weathering
A type of weathering in which rock is physically broken into smaller pieces
define chemical weathering
The process that breaks down rock through chemical changes
Define oxidation
iron combines with oxygen in the presence of water creating rust this is oxidation
Describe in a full sentence how weathering and erosion work together
Weathering and erosion and work together continuously to wear down and carry away the rocks at earths surface
What are the five forces of mechanical weathering
Freezing and thawing Release of pressure Plant growth Actions of animals abrasion
Describe the mechanical weathering type of freezing and thawing
When Water freezes in a crack in a rock it expands and makes the crack bigger
Describe release of pressure
As erosion removes material from the surface of a mass of rock pressure on the rock is reduced this release of pressure causes the outside of the rock to crack and flake off
Describe plant growth
Roots of trees and other plants enter cracks in rocks as roots grow they forced the cracks farther apart over time the roots of the small plants can pry apart cracked rock
Actions of animals
Animals that burrow in the ground including moles gophers and prairie dogs and some insects loosen and breakapart rocks in the soil
Describe abrasion
Sand and other rock particles that are carried by wind water or ice can wear away exposed rock surfaces like sandpaper on wood
What are 5 causes of chemical weathering
The action of water Oxygen ( oxidation) Carbon dioxide Living organisms Acid rain
Describe the action of water
Water weather’s rock by dissolving it
Describe oxygen (oxidation )
Iron combines with oxygen and presence of water this is oxidation this causes rust which makes rock soft and crumbly and gives it a red or brown color
Describe carbon dioxide C.W.
Carbon dioxide dissolves in rain water and water that sinks through air pockets in the soil this carbon acid which easily weather’s rocks such as marble and limestone
Describe living organisms C.W.
When roots and plants push into cracks in rocks these routes released weak acids that dissolve rock around the roots lichens that sit on rocks also produce this acid
Describe acid rain
Burning coal oil gas etc. causes air pollution full of sulfur carbon and nitrogen compounds. these compounds react chemically with water vapor forming acid this acid falls in rain and rapidly weather’s rocks
What are two factors that determine the rate of weathering
Type of rock
Climate
How does type of rock determine the rate of weathering?
Materials in the rock determine how fast it weathers. rock with minerals that dissolve easily in water weather slower than rocks with minerals that don’t dissolve easily
How does climate determine the rate of weathering ?
Climate refers to the average weather conditions in an area both chemical and mechanical weathering occur faster and wet climates
