Clogherhead, the source of stones for Newgrange, is the site of a 420 million-year-old geological event

@mythicalireland

Today, I’m at Clogherhead in County Louth. It’s a remarkable place in the geological history of Ireland, and also in the story of the great monument of Newgrange. It is the site of an incredible event that took place long before man ever walked the earth. Four hundred and twenty million years ago, two continents collided here. Modern geologists call them Laurentia and Avalonia. Before they collided, they had been separated by an ocean thousands of kilometres wide. The Iapetus Suture is a fault or seam that runs from Clogherhead to the Shannon Estuary. Everything north of that fault was once on the continent of Laurentia, and everything south of it on Avalonia. Clogherhead is the only place in Ireland where the results of this collision of continents can be seen on the surface. The vertical bedding seen in the cliffs here resulted from immense pressure during the Caledonian mountain-building period. The area around Clogherhead provides dramatic views of these folded, upturned rock layers. The builders of Newgrange took advantage of this geological formation. 5,200 years ago, they prised apart large slabs of greywacke – a type of muddy sandstone – and transported them by boat down along the Irish Sea and into the River Boyne as far as Brú na Bóinne. That journey is 31 kilometres or 19 miles. They brought several hundred slabs, weighing between one and ten tonnes apiece, which they used to construct the passage and chamber and the huge kerb of stones around the monument. Next time you visit Clogherhead, remember that it is a place that is vastly ancient, and think about how precarious those stone-bearing journeys to Brú na Bóinne must have been in the New Stone Age. It really is a most incredible place. #Clogherhead #geology #prehistory #Newgrange #ancienthistory

♬ original sound - mythicalireland

Clogherhead in County Louth is a most amazing location. It has a remarkable role in the geological history of Ireland, and also in the story of the great monument of Newgrange.
It is the site of an incredible event that took place long before man ever walked the earth.
Four hundred and twenty million years ago, two continents collided here.
Modern geologists call them Laurentia and Avalonia. Before they collided, they had been separated by an ocean thousands of kilometres wide.
The Iapetus Suture is a fault or seam that runs from Clogherhead to the Shannon Estuary. Everything north of that fault was once on the continent of Laurentia, and everything south of it on Avalonia.
Clogherhead is the only place in Ireland where the results of this collision of continents can be seen on the surface.
The vertical bedding seen in the cliffs here resulted from immense pressure during the Caledonian mountain-building period.
The area around Clogherhead provides dramatic views of these folded, upturned rock layers.
The builders of Newgrange took advantage of this geological formation.
5,200 years ago, they prised apart large slabs of greywacke – a type of muddy sandstone – and transported them by boat down along the Irish Sea and into the River Boyne as far as Brú na Bóinne.
That journey is 31 kilometres or 19 miles. They brought several hundred slabs, weighing between one and ten tonnes apiece, which they used to construct the passage and chamber and the huge kerb of stones around the monument.
Next time you visit Clogherhead, remember that it is a place that is vastly ancient, and think about how precarious those stone-bearing journeys to Brú na Bóinne must have been in the New Stone Age.
It really is a most incredible place.
#Clogherhead #geology #prehistory #Newgrange #ancienthistory