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16 October 2014

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Coasts Mountains, Lakes & Rivers Settlement Land Use & Economic Activity Ecosystems
Headlands, Bays & Beaches Erosion, Caves, Stacks & Stumps Impact of Erosion Tourism & Human Interaction
Erosion, Caves, Stacks and Stumps clipWatch Video Map

Script

Key Points

This is an arch, it was formed when two caves were eroded in each side of a headland. Eventually the caves joined up to form an arch.

The coast at the White Rocks in County Antrim is an example of an coastal erosion landscape.

The sea is a powerful agent of erosion. Hard rocks like basalt or granite will resist erosion. Softer sedimentary rocks made of chalk like these at the White Rocks will be worn away much more easily.

On this stretch of coast we can see some of the features which have formed from this type of erosion. Headlands have been worn away to form caves, stacks and stumps. The sand on the beach is made up of tiny bits of rock which have been eroded from the surrounding cliffs.

On the beach you can see a large pillar of rock. This is a stack and beside it is a stump. A stack is a pillar of rock which was left behind when an arch collapsed. Stacks will eventually fall over or be worn down into stumps. In time even the stump will be eroded and will disappear.

If you look at the coastline behind the beach you can see how the sea is slowly eroding the rock and cutting in to the land.

In winter, during a northerly gale, large waves crash against the shore with great force. This bombardment opens up cracks in the rocks, and breaks them into smaller pieces.

Here you can see a number of caves which the sea has cut into the chalk. As these caves are eroded they will widen and deepen and may eventually collapse. This will affect any roads or buildings on the cliff above.

See how this headland has been eroded by the sea to form two arches. Look carefully at the base of the arch and you can see how the waves are attacking the rock.

In winter, large waves crash against the shore opening up cracks in the rocks.

Hard rocks like basalt will resist erosion. Softer sedimentary rocks like chalk will be worn away much more easily.

An arch is formed when two caves break through a headland.

A stack is a pillar of rock which was left behind when an arch collapsed. Stacks will eventually fall over or be worn down into stumps.



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