http://www.flickr.com/photos/rosedavies/534844636/

This is a chalk headland.

Because chalk is a sedimentary rock, lines of weakness run throughout

the headland.

Hydraulic action will exploit these weaknesses.

Between low and high tide, waves will attack the

base of the headland.

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The process of corrasion will undercut the base of the cliff, forming a wave

cut notch.

The undercutting by corrasion will make the

cliff unstable.

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LTThis creates small caves which are enlarged over

time by erosion.

Caves develop on either side of the headland.

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These caves erode back through the headland and

meet, forming an arch.

Continued erosion at the base of the arch will cause

the roof to become unstable.

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LTIt may collapse leaving a stack.

Continued erosion of the base of the stack may lead to its collapse, resulting in

a stump.

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