How the Giant's Causeway was formed

Have you ever been to the Giant's Causeway in Northern Ireland?

It's one of the UK's most instantly recognisable natural landmarks with its famous basalt columns a common sight in tourist brochures, on postcards and even computer screensavers.

Research by the Geological Survey of Northern Ireland (GSNI) and the British Geological Survey (BGS) has now revealed these rocks didn't take quite as long to form as had previously been thought.

Their studies have said that volcanic rocks in this region formed in just 5.5 million years – 8 million years less than previous estimates.

The Giant's Causeway is located in Country Antrim, and was formed by intense volcanic activity which forced molten rock up through cracks in the earth.

This lava flowed and then cooled, contracted and cracked, creating around eight-sided basalt columns.

These are also part of a famous legend about a giant called Finn McCool (Fionn mac Cumhaill in Irish).

It's said that he built the causeway as a bridge to Scotland, in order to fight another giant who was taunting him.

According to a different legend, in another fight with a giant, Finn threw some earth which missed, landed in the sea, and became what we now know to be the Isle of Man.

GSNI Chief Geologist Prof Mark Cooper explained that for decades it was believed that the volcanic activity responsible for creating the Giant's Causeway stretched over 13.5 million years, during a time period referred to as the Paleogene.

But new analysis has made a new timeline for volcanic activity across all of Northern Ireland.

"These findings have completely changed how we understand the Northern Ireland's place in the wider North Atlantic volcanic story," he said.

These new discoveries also help give greater understanding of the Earth processes that caused the development of the broader Antrim Plateau area, along with the Mourne Mountains and Slieve Gullion.

They also shed light on globally significant volcanic events seen in rocks as far away as Greenland.

The research work is part of a British Geological Survey project to better understand the UK's geology.