Where giants walked – Giant’s Causeway Northern Ireland
Transcript/Blogpost
There was an Irish giant called Finn McCool, who was challenged to a fight by the Scottish giant Benandonner. Finn accepted and built a causeway of huge basalt columns across the North Channel of Northern Ireland, so that the two giants could meet.
This story of course has many versions and in one Finn defeats Benandonner. In another, Finn hides from Benandonner, when he realises that his enemy is much bigger than he is and Finn’s wife disguises Finn as a baby and tucks him in a cradle. When Benandonner sees the size of the “baby”, he decides that its father, Finn, must be a giant among giants. He flees back to Scotland in fright, destroying the causeway behind him, so that Finn would not be able to follow him. Across the sea, there are identical basalt columns at Fingal’s Cave on the Scottish isle of Staffa, and it is possible that the story was influenced by this similarity in geology.
This is just one of the legends that abound all over Ireland – a land of giants and leprechauns. The causeway that Finn Mc Cool created is known as the Giant’s Causeway, in County Antrim in the north coast of Northern Ireland. The Causeway is also referred to as the 8th wonder of the world. It covers an area of about 40,000 interlocking basalt columns, along 4 miles or 6 km of the coast. All of them are the result of an ancient volcanic fissure eruption.
The tops of the columns form steppingstones that lead from the cliff foot and disappear under the sea. As is common in nature, most of the columns are hexagonal, although there are also some with four, five, seven or eight sides. The tallest ones are about 12 metres (39 ft) high, and the solidified lava in the cliffs is 28 metres (92 ft) thick in places.
How were the columns really created?
About 200 to 175 million years ago, the Eurasian and American continents that were bound together as part of the supercontinent of Pangea, started to break apart, creating the mid-Atlantic ridge as they moved away from each other. This ridge primarily lies at the bottom of the entire Atlantic Ocean – from north to south. But portions of it have enough elevation to extend above sea level, for example in Iceland, which represents the largest portion of the mid-Atlantic ridge exposed above sea level. If you visit the country, you can see it.
During the next few million of years volcanic activity continued under the Earth’s surface. Then around 50 to 60 million years ago, during the Paleocene Epoch, the northern coast of Northern Ireland, specifically County Antrim, was subject to intense volcanic activity, when highly fluid molten basalt intruded through chalk beds to form an extensive volcanic plateau. As the lava cooled, contraction occurred.
The horizontal contraction fractured in a similar way to drying mud, with the cracks propagating down as the mass cooled, leaving pillarlike structures, which also fractured horizontally into what are called “biscuits”. Eventually, the extensive fracture network produced the distinctive columns that can be seen today. The size of the columns was primarily determined by the speed at which lava cooled. The basalts were originally part of a great volcanic plateau called the Thulean Plateau, which formed during the Paleocene.
Some of the structures in the area have faced several million years of weathering, and can resemble everyday objects, adding more to Finn McCool’s legend. These include the Organ and Giant’s Boot structures. Other features include many reddish, weathered low columns known as Giant’s Eyes, created by the displacement of basalt boulders; the Shepherd’s Steps; the Honeycomb; the Giant’s Harp; the Chimney Stacks; the Giant’s Gate and the Camel’s Hump.
The Giant’s Causeway was declared a World Heritage Site by UNESCO in 1986 and a national nature reserve in 1987 by the Department of the Environment for Northern Ireland.
If you happen to be in Northern Ireland, it is definitely worth a visit. An experience you will never forget.
Saima Baig
I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.
