Volcanic lava that cooled 60 million years ago is today one of the geological wonders of the world.
The coastal landscapes around the UK are made up of rocks that vary in age. The oldest at around 3 billion years, are found in the hard rocky cliffs of the extreme northwest of Scotland and the Outer Hebrides. The youngest are the soft clays and sandstones on the coasts of East Anglia that are less than 3 million years old. The spectacular Giant’s Causeway is made of black volcanic rocks (basalt) some 60 million years old.
Hexagonal columns
The Causeway was created at a fascinating time in the Earth’s history, when the Atlantic Ocean was just beginning to form. The North Atlantic Ocean was created over millions of years through the steady widening of the ocean floor, either side of a submarine ridge in the middle of the sea.
As the land was being slowly torn apart by tectonic forces in the Earth’s crust, black molten lava began erupting over its surface. The lava cooled and shrank into the strange hexagonal columns that give the Giant’s Causeway - and its Scottish counterpart Fingal’s Cave - its impressive character.
Legend of the giant’s causeway
According to legend, the columns were created by the mythical Irish giant Finn McCool in his argument with the Scottish giant Fingal.
After hurling insults and rocks at one another across the sea, Finn wrenched up giant blocks to create a causeway between Ireland and Scotland so that Fingal could come across and they could fight it out face to face. Fingal, frightened by a trick played by Finn, fled back to Fingal’s Cave, tearing up the causeway as he went, leaving only remnants behind on both shores.
