Giant’s Causeway formed much quicker than previously thought, scientists discover

The distinctive columnar landscape at Giant's Causeway in Co Antrim, Northern Ireland, was formed during intense volcanic activity, which forced molten rock up through cracks in the earth.

Thick lava flows then cooled, contracted, and cracked, creating around 40,000 basalt columns that are now internationally famous.

However, new research by the Geological Survey of Northern Ireland (GSNI) and the British Geological Survey (BGS) has revealed that the volcanic rocks of the region formed in just 5.5 million years, 8 million years less than previous estimates.

In a statement on June 15, BGS said that by uing state of the art techniques, scientists were able to reconstruct a new timeline for volcanic activity across Northern Ireland.

"It now firmly connects the Earth processes that caused the development of the Giant’s Causeway and the broader Antrim Plateau area, along with the Mourne Mountains and Slieve Gullion, to a globally significant volcanic event seen in rocks as far away as Greenland and known as the North Atlantic Igneous Province around 60 million years ago," BGS said.

Hexagonal stones at the Giant's Causeway, County Antrim. (Tourism Ireland / Ireland's Content Pool)

Professor Mark Cooper, GSNI Chief Geologist, commented: "The Giant’s Causeway is one of the world’s most instantly recognisable landmarks.

"For decades, it was believed the region’s volcanic activity, responsible for the Giant’s Causeway, stretched over 13.5 million years during a time period we refer to as the Paleogene.

"Our research shows that this activity was far more concentrated, with geological processes acting much faster than previously thought.

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

Dr. Simon Tapster, Geochronologist at the British Geological Survey, added: "Cutting-edge analysis has allowed us, for the first time, to place the volcanic activity that led to the formation of the Giant’s Causeway within a much more precise global context.

"It’s a remarkable reminder that the iconic 40 000 basalt columns that we can still see today in Northern Ireland can also help us to understand the globally impacting geological transformations during the Paleogene period."

The research is part of a wider initiative at the British Geological Survey to improve the understanding of the UK’s geology through better quantifying geological time in the rocks around us.

The research paper, "Feeling the pulse? Paleogene chronostratigraphy of Northern Ireland and the north of Ireland temporally coupled to the North Atlantic Igneous Province Open Access," is now available to read on GeoScienceWorld.