Mon Prof Augmenté
From Crack to Stump
Age 14 · Geography
Waves pound a headland and force air and water into weak spots in the rock, slowly widening a crack into a cave and then an arch. When the arch roof collapses it leaves a lone stack, which wears down into a low stump.
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In the picture
- Crack: a weak line in the cliff that waves attack first
- Cave: the crack worn into a hollow at the waterline
- Arch: the cave cut right through the headland
- Stack: a lone pillar left when the arch roof falls
- Stump: the stack worn down, covered at high tide
Examples
- The Old Harry Rocks chalk stacks on the south coast of England
- The Étretat arches on the Normandy coast of France
Key takeaways
- Waves erode fastest along cracks and weak rock
- The sequence always runs crack, cave, arch, stack, stump
Quiz: From Crack to Stump (Age 14)
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Where on a headland do waves wear the rock away fastest?
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What is left when the roof of an arch collapses?
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Which order shows how a headland is worn away?
The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.
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