Weathering and Erosion Flashcards
What is weathering?
The breakdown of rocks and minerals by mechanical and chemical processes
What is erosion?
Movement of material by wind, water, gravity,glaciers, and organisms
What are the 5 types of mechanical/physical weathering
Pressure release fracturing, thermal expansion/contraction, frost wedging, abrasion, and salt cracking.
What is mechanical/physical weathering?
The breaking of rocks into smaller pieces by physical processes
What is chemical weathering?
The breakdown and changing of rocks and minerals caused by exposure to air, water and other chemicals in the environment
What are the three types of chemical weathering?
Hydrolysis, oxidation, and dissolution
What is pressure release fracturing?
Pressure released as overlaying layers have eroded away. Looks like the rocks are stretching.
What is thermal expansion/contraction?
Heat expands rock, cold contracts. This caused the rocks to crack or break apart
What is frost wedging?
Water freezes in the crack of the rock and the expansion wedges the rock apart
What is abrasion?
Mechanical weathering of rocks by friction and impact. Increases surface area.
What is salt cracking?
Salts found in pores of rocks crystallize and widens the crack and pushes grains apart
What is hydrolysis?
Water reacts with existing minerals and causes the minerals to look grey and discolored
What is oxidation?
When minerals react with oxygen and results in a more stable minerals (rust)
What is dissolution?
Minerals and rocks dissolve and are carried away
What is water erosion?
The removal of soil by water and transportation of the eroded soil
