• Including keywords where possible, describe
and explain how erosion can influence the
coast. You may use a diagram.
Recap: What are the 4 Types of
Erosion is……. the wearing away of
materials by one of four processes:
Corrosion = chemical reactions of salt water
weakening rocks like an acid
Attrition = Pebbles hitting into each other or into
cliffs making rocks break and get smaller and rounder
Abrasion = ‘sand paper’ effect. Waves throwing small
stones and pebbles at cliffs and beaches to smooth the
Hydraulic Action = Power of the water forcing its way
into cracks and weaknesses in rocks, splitting apart
Wave-cut platform –
Burgh Island, Devon
Wave cut platform
Beaches develop where the supply of sediment exceeds loss
through backwash and longshore drift.
Beaches are usually distinguished as either …
Shingle beaches are free draining so there is little backwash of material to sea.
As a consequence, they are usually steeper.
Spits and Bars
Where there is a change in the coastline e.g. a headland or an
estuary mouth, longshore drift may continue to deposit
sediments into the sea forming a spit.
Local currents and changes in wind direction may curve
the end of the spit landwards creating a hooked tip.
The presence of the estuary discharging river water into
the sea prevents the spit from developing into a bar.
Such a feature is known as a recurved spit
• How does geology influence the speed of
erosion at the coast?
The geology of the coast
affects how much it is
More resistant rocks
(e.g. chalk) erode more
slowly than less
resistant rocks (e.g. clay,
This gives us BAYS
• The Jurassic Coast is a section of coastline in
Southern England that shows geology over
millions of years.
• The coastline first began forming 250million
• Dorset shows the geology of the Jurassic
period, between 200-140million years ago