landforms from erosion (some from erosion and deposition)

Question 1

What is a discordant coastline?

Answer 1

A coastline where bands of different restitance rocks run perpendicular to the Coast, this causes headlands bays and coasts to form

Question 2

Give a step by step guide on how a wave cut platform forms

Answer 2

1)waves erode base of cliff using the erosionsl processes
2) over time cliff will be undercut forming a wave cut notch
3) eventually the cliff collapses and retreats backwards, leaving a flat rock base called a wave cut platform

Question 3

How is a cave formed ?

Answer 3

Cracks form in the headland through erosion all processes, crack becomes larger due to continual erosion by waves eventually forming a cave

Question 4

How does an arch form ?

Answer 4

Erosion causes cave to become larger eventually braking through other side of headland forming an arch

Question 5

How does a stack form ?

Answer 5

Sides of arch continue to
erode whilst roof of arch is weathered. Eventually sides can no longer support roof collapses into seas due to gravity, this leaves a stack now separate from main land.

Question 6

How is a stump formed ?

Answer 6

The stack is undercut by erosion at the base, until it collapses into the sea to form a stump

Question 7

How does a bay form?

Answer 7

The more easily eroded rock erodes quicker on a discordant coastline causes bays to form

Question 8

How does a headland form?

Answer 8

Where easier eroded rock erodes quicker on discordant coastline leaving just of rock on either sides of the bay

Question 9

What are Concordant coastlines?

Answer 9

Where bands of soft and hard rock run horiziontal to the coastline.

Question 10

How are coves formed?

Answer 10

An area of weakness on a concordant coastline erodes faster than the rest of the hard rock until it reaches the softer rock and the softer rock erodes much quicker creating a cove

Question 11

How are interlocking spurs formed?

Answer 11

In the upper course there is more
vertical erosion. The river cuts down into the valley. If there are areas of hard rock which are harder to erode, the river will bend around it. This creates interlocking spurs

Question 12

What is a waterfall? Why do they form?

Answer 12

A waterfall is a sudden drop along the river course. It forms when there are horizontal bands of resistant rock (hard rock) positioned over exposed, less resistant rock (soft rock).

Question 13

How do waterfalls form?

Answer 13

1)The soft rock is eroded quicker than the hard rock and the hard rock is undercut forming an overhang.
2)Abrasion and hydraulic action erode to create a plunge pool
3)Over time this gets bigger, increasing the size of the overhang until the hard rock is no longer supported and it collapses.
4)This process continues and the waterfall retreats upstream.
5)A steep-sided valley is left where the waterfall once was. This is called a
gorge

Question 14

How is a gorge formed?

Answer 14

As a waterfall retreats it creates a gorge

Question 15

What happens in the middle course of a river which causes meanders to form?

Answer 15

As the river makes its way to the
middle course, it gains more water and therefore more energy.
Lateral erosion starts to widen the river. When the river flows over flatter land, it develops large bends called meanders
.

Question 16

How does a meander form?

Answer 16

1)As a river goes around a bend, most of the water is pushed towards the outside. This causes increased speed and therefore increased erosion (through hydraulic action and abrasion).
2)The lateral erosion on the outside bend causes undercutting of the bank to form a
river cliff.
3)Water on the inner bend is slower, causing the water to lose energy and deposit the eroded material, creating a gentle slope of sand and shingle.
4)The build-up of deposited sediment is known as a slip-off slope

Question 17

How are oxbow lakes formed?

Answer 17

Erosion narrows the neck of the land within the meander and as the process continues, the meanders move closer together. When there is a very high
discharge (usually during a flood), the river cuts across the neck, taking a new, straighter and shorter route. Deposition will occur to cut off the original meander, leaving a horseshoe-shaped oxbow lake.