First 159 words of the document:
Formation of Stacks and Stumps
Definition: Stacks are steep, isolated islands of rock, separated from a
headland by the action of waves, as when the overhanging section of a
sea arch is eroded. The stump is the collapsed stack.
The cracks and weaknesses in the headland are eroded by waves.
This is enlarged to form a cave by the pounding of the waves.
This compresses air in the rock face.
Abrasion is where material carried by the water is flung against the cliff.
The cave is made bigger, and if there is one on either side of the
headland, an arch will result when they join.
Continued erosion will wear away supporting rock this will collapse.
This will leave an isolated piece of rock separated from the headland.
These stacks will eventually wear into stumps.
Effect: over time, the cliff eventually retreats.