The zigzag cliff

If you go to the beach and look right, you will find yourself hit smartly in the face by the zig zag cliff.

Showing the extraordinary zigzag in the cliff
The Zigzag cliff

The Millook zigzag cliff

A long time ago, I mean a very long time ago, muddy rivers spewed mud and silt and all sorts of gunge into the sea.  Winter floods brought down tons which settled on the seabed.  In some winters the rivers brought sand, in others fine grains of rock.  Last year’s mud settled and pressed down on the previous year.   The weight of new layers on top squeezed the mud dry even though it was under the sea. The pressed and dried layers turned into soft rock.  Layer upon layer upon layer.  Some were thick, some thin.

Then along came a whole big continent which was moving north.  Like a heavy goods train, it was not fast but it was impossible to stop.  It just kept on going at a few inches a year. There was a slow motion crash with our layers which by now were deep underground. They got awfully hot. The sandy layers hardened like cement; the silty grey rocks hardened and became the thin slates that we skim over the water –sometimes they can bounce eight times: has anyone achieved more?

These layers of hot rock started to crumple up: a carpet would fold up if you pushed it along a polished floor against a wall.   They folded and concertinaed into zigzags.

Sometimes a bit of molten rock from deep down in the Earth forced its way up into these layers of rock.  This cooled and hardened.  It is the white quartz you can see in some of the pebbles.

This pushing went on for ages; the folds were pushed high up and became mountains – more than twenty thousand feet high: one of the highest mountain ranges that the world has ever seen. It went from the Baltic Sea to Portugal.

In the end the advancing continent slowed down and stopped. Rain and snow and wind and frost eroded the mountains. Ever so slowly. The mountains were worn away over a lot of millions of years.  Now you can see nothing of the mountains. Little remains except some bits of Portugal, the bottom left-hand corner of Ireland, the Gower Peninsula and Millook cliff.  Its magnificent chevron folds are famous worldwide.  Millook is rated as one of the top ten geological sites in Britain.

Envoi:  the Environment Agency has measured erosion by the sea at Millook at roughly 5cm/year. So when Jesus was alive the cliff would have been 100 metres inland.