What are the landforms caused by erosion Friday 30 August 2019 What is a landform What do you think this means A landform is something that has been createdformed by natural processes Examples include a coastal stack ID: 935444
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Slide1
Focus Task
Describe the 4 types of erosion.
What are the landforms caused by erosion?
Friday, 30 August 2019
Slide2What is a landform?
What do you think this means?
A
landform is something that has been created/formed by natural processes.
Examples include a coastal stack.
Slide3What geomorphic processes have caused this landform?
Slide4What is geology?
Geology
is the study of different rock type.
At a coastline, usually there will be a difference in the hardness of rock, hard and soft.
This creates landforms.
Slide5Where was the coastline originally?
Slide6How do headlands and bays form?
Headlands and bays
form along coastlines where there are alternating outcrops of resistant (hard) and less resistant (soft) rock.
Task- on your sheet,
explain
the formation of headlands and bays.
Slide7How do headlands and bays form?
Rock type
is one of the main factors affecting the shape of a coastline.
Headlands and bays form along coasts that have alternating bands of harder and softer rock. The hard rock is more resistant to erosion, so the coastline is worn away less quickly leaving a headland
sticking out into the sea.
Sketch the diagram above and add the following labels:
Bay
Headland
Hard, resistant rock.
Softer, less resistant rock
Bays are sheltered by headlands
Headlands are left sticking out making them more vulnerable to erosion
Slide8Crack, cave, arch, stack
How do you think the coastal stack has formed?
Slide9Crack, cave, arch, stack
How do you think the coastal stack has formed?
https://
www.bbc.com/bitesize/clips/zccd2hv
Crack
The process of hydraulic action helps to open cracks up in the headland (cliff face).
Slide11Cave
Once widened enough by hydraulic action, destructive waves begin to hurl rocks/pebbles into the crack (
abrasion).
This widens and deepens the crack to form a cave.
Slide12Arch
Abrasion continues to deepen the cave until it breaks through to the other side of the headland.
An
arch is formed.
Slide13Stack
Freeze thaw (water entering cracks, freezing and widening)
weakens
the top of the arch.Eventually, this becomes so weak that it collapses, due to a lack of support, leaving behind a stack.
Slide14Stump
The base of the stack becomes exposed to abrasion & hydraulic action and it becomes weak.
Eventually, the stack collapses, leaving behind a
stump.
Slide15Activity
On the sheet that you have been given, sketch the formation of a coastal stack.
Slide16Activity
1. Headland
2. Crack
3. Cave
The headland has
been left because it’s made of hard rock the erodes slowly.
A small crack forms in the softer
rock (weakness) of the
headland.
The crack gets
deeper due to hydraulic action and forms a cave.
4. Arch
5. Stack
6. Stump
The cave
erodes all the way through and forms an arch.
The arch collapses
and leaves a stack due to weathering and no support.
The stack erodes
and leaves a stump.
Slide17Paired activity. Give yourself a number of 1 or 2.
Plenary
Person 1- explain the formation of headland and bays.
Person 2- explain the formation of a coastal stack.
Quick Quiz.
What is meant by erosion?
What is abrasion?What is attrition?What is hydraulic action?What is solution?
Plenary
Slide19Create and label your pop-up headland and stick it into your book.
Extension