Formation of Coastal Landforms - Geography AQA GCSE, Coats
Headlands and bays
They form at a discordant coastline with hard and soft rock, where the soft rock erodes faster
leaving a bay with headlands jutting out on either side.
Wave cut notch and platform
Erosion at the base of the cliff, specifically hydraulic action and abrasion, creates an
undercut in the rock, known as a wave cut notch.
This grows over time due to repeated erosion, causing the rock above to become unstable.
Eventually it will collapse under its own weight and the process begins again. Slowly the
cliffs retreat leaving behind a wave cut platform, a sloping rocky
platform.
Cave, arch, stack, stump
A crack in the cliff will appear due to compression. Abrasion and hydraulic action widen the
crack to form a cave. Erosion makes the cave larger until it cuts through the headland to
make an arch. Due to chemical weathering on the roof of the arch and hydraulic action at the
base, the arch will collapse. This leaves an isolated pillar of rock, a stack. The stack will be
eroded and collapse, leaving behind a stump.
Beaches
Beaches are made up of deposits of material, for this to occur waves must have little energy
and so often form in a sheltered bay. Constructive waves build up beaches as they have a
strong swash and a weak backwash.
Sand dunes
Sand deposited on the beach is blown inwards by onshore winds.
Embryo dune, fore dune, yellow dune, grey dune, dune slack
Spits
A spit is an extended stretch of beach material that projects out to sea and is joined to the
mainland at one end. Spits are formed where the prevailing wind blows at an angle to the
coastline, resulting in significant longshore drift. This results in deposit of material out to sea,
forming a spit. Strong winds can cause the end of a spit to become recurved.
Bars
When a spit grows right across a bay due to longshore drift. It traps a freshwater lake,
lagoon, behind it.
Headlands and bays
They form at a discordant coastline with hard and soft rock, where the soft rock erodes faster
leaving a bay with headlands jutting out on either side.
Wave cut notch and platform
Erosion at the base of the cliff, specifically hydraulic action and abrasion, creates an
undercut in the rock, known as a wave cut notch.
This grows over time due to repeated erosion, causing the rock above to become unstable.
Eventually it will collapse under its own weight and the process begins again. Slowly the
cliffs retreat leaving behind a wave cut platform, a sloping rocky
platform.
Cave, arch, stack, stump
A crack in the cliff will appear due to compression. Abrasion and hydraulic action widen the
crack to form a cave. Erosion makes the cave larger until it cuts through the headland to
make an arch. Due to chemical weathering on the roof of the arch and hydraulic action at the
base, the arch will collapse. This leaves an isolated pillar of rock, a stack. The stack will be
eroded and collapse, leaving behind a stump.
Beaches
Beaches are made up of deposits of material, for this to occur waves must have little energy
and so often form in a sheltered bay. Constructive waves build up beaches as they have a
strong swash and a weak backwash.
Sand dunes
Sand deposited on the beach is blown inwards by onshore winds.
Embryo dune, fore dune, yellow dune, grey dune, dune slack
Spits
A spit is an extended stretch of beach material that projects out to sea and is joined to the
mainland at one end. Spits are formed where the prevailing wind blows at an angle to the
coastline, resulting in significant longshore drift. This results in deposit of material out to sea,
forming a spit. Strong winds can cause the end of a spit to become recurved.
Bars
When a spit grows right across a bay due to longshore drift. It traps a freshwater lake,
lagoon, behind it.
