Headland erosion
Erosion processes that form sea caves, arches and stacks
Caves, arches and stacks
How did the original headland become eroded to the present coastal landscape?
Headland erosion
A number of stages are involved:
- All rocks have lines of weakness; the sea and its waves use hydraulic action, abrasion and solution to erode along any lines of weakness.
- These lines of weakness get enlarged and develop into small sea caves.
- The Recess in a cliff where waves have enlarged a crack in the rock face. are deepened and widened on both sides of the headland until eventually the sea cuts through the headland, forming an A natural rock formation often created by two sea caves eroding backwards towards each other until the back walls disappear..
- The rock at the top of the arch becomes unsupported as the arch is enlarged, eventually collapsing to form a stack.
- The A pillar of rock left standing in the sea when the top of an arch has collapsed. gets eroded until only a stump remains.
- Over time the stump will disappear.
- As the headland retreats under this erosion, the gently sloping land at the foot of the retreating cliff is called a wave-cut platform.