Section 23.2 Weathering and Mass Movement Flashcards
What is erosion?
the process that wears down and carries away rock and soil
What is weathering?
process by which rocks are chemically altered or physically broken down into fragments ar or near the Earth’s surface
What is mechanical weathering? (list 3 examples)
process of physically breaking rock into smaller fragments. Examples include frost wedging, abrasion, and root pry
What is abrasion?
when rock scrape or grind against one another
What is chemical weathering? (list 2 specific ways- rain water and oxidation)
process which rock is broken down by chemical reactants. 2 specific ways include:
1) water is an effective solvent, also many times includes carbonic acid which reacts readily with certain rocks
2) oxidation is the process that rusts minerals rich in iron
What is mass movement? (list 4 examples and explain each)
the downward movement of rock and soil due to gravity. Examples include:
1) landslides- rapid movement of rock and soil usually after heavy rain, earthquakes, or volcanic activity
2) mudflows- rapid movement of mud after thick layers of thin sediment build up and are subject to heavy rainfall
3) creep- soil gradually moving downslope due to formation of ice- thaw-ice-thaw
4) slumping-curved scar left after landslide
What are the agents of erosion?
erosion acts through weathering, the force of gravity, through the movement of streams, groundwater, glaciers, wind, and waves
What causes mechanical and chemical weathering?
Mechanical- occurs through frost wedging, abrasion, and growth of plant roots
Chemical- chemical reactions dissolve the minerals making up rock
What 2 main factors affect the rate of weathering of rock?
1) Temperature
2) Availability of water
3) Type of rock
What force causes mass movement?
gravity moves loose material down a slope
