Formation of a waterfall

Question 1

Point 1
(Differential erosion takes….)

Answer 1

Differential erosion takes place over bands of more and less resistant rock. Softer rock is more easily eroded.

Question 2

Point 2
(Hydraulic action wears…)

Answer 2

Hydraulic action wears away the softer rock. This is when air is compressed into the riverbank causing materials to be dislodged.

Question 3

Point 3
(Abrasion also…)

Answer 3

Abrasion also wears away the softer rock. This is when the force of the water throws bedlam against the banks causing erosion.

Question 4

Point 4
(Solution may erode…)

Answer 4

Solution may erode some rock types i.e limestone, when soluble rocks react with acids in the water.

Question 5

Point 5
(Undercutting causes an…)

Answer 5

Undercutting causes an overhang of the hard rock and over time the hard rock is unsupported and collapse due to gravity into the plunge pool.

Question 6

Point 6
(Attrition occurs in the…)

Answer 6

Attrition occurs in the plunge pool where the rocks from the collapsed overhang hit off each other. These rocks then erode the plunge pool further through abrasion.

Question 7

Point 7
(Overtime, the waterfall…)

Answer 7

Overtime, the waterfall retreats upstream creating a steep sided gorge.