geography exam prep Flashcards
1
Q
what are the 3 types of weathering?
A
- mechanical
- chemical
- biological
2
Q
describe mechanical weathering?
A
- freeze-thaw
3
Q
describe chemical weathering?
A
- acid rain (mixed with pollution)
4
Q
describe biological weathering?
A
- rocks that have been broken down by living organisms
5
Q
what is a V-shaped valley?
A
- formed by erosion from a river or stream over time
6
Q
what is erosion?
A
- the break down and transport of rocks (smooth and round)
7
Q
what is a meander?
A
- as the river erodes to the right side then to the left side, it forms large bends
8
Q
what is a waterfall?
A
- formed in the upper stages of a river where it follows over different bands of rock
9
Q
what are the 3 stages of freeze-thaw weathering?
A
stage 1:
- water seeps into cracks and fractures in the rocks
stage 2:
- when water freezes, it expands about 9%. this wedges apart the rock
stage 3:
- with repeated freeze-thaw cycles, the rock breaks off
10
Q
what is deposition?
A
- when the river loses energy
11
Q
describe hydraulic action in erosion?
A
- the sheer power of the water as it smashes against the river banks
12
Q
what are the 3 factors leading to deposition?
A
- shallow water
- slower velocity at the end of the rivers journey
- when the volume of water decreases
13
Q
describe solution in erosion?
A
- a chemical reaction that dissolved rocks
14
Q
describe abrasion in erosion?
A
- when pebbles grind along the river bank and bed in a sandpapering effect
15
Q
describe solution in transportation?
A
- minerals dissolve in water and are carried along
