Co. Meath - Newgrange

Volcanic breccia at Newgrange

Now that the Dublin Stone Show had been successfully completed and I had finished the reports on the County Geological Sites that I had surveyed, I was at a bit of a loss what to do next. When asked if I could collect the latest edition of ES2k, I jumped at the chance.

Building stones

Knowing that the 275 km round trip, from Dublin to Co. Armagh and Co. Monaghan and back, would take most of the day and that there wouldn’t be enough time to carry out field survey work, I made the most of the opportunity to relax - and went to see Newgrange. 

Older than Stonehenge and the Egyptian pyramids, its restoration – after many centuries of neglect and recycling of the stones that were originally used in its construction – proved very controversial amongst archaeologists and antiquarians.

From the viewpoint of a geologist, I found it fascinating - another case for the Geological Detective.

In Co. Meath, along with every other place that I visited in Ireland, the power of the vast ice sheets that once covered the British Islands is clearly demonstrated by its spectacular mountain landscapes – but around the River Boyne, the recent geology gently fades into history.
 

A view of Newgrange

Using my Heritage Ireland membership card, I enjoyed the traditional tourist experience of entering its interior and appreciating its great significance but, with a limited amount of time on my hands to get to Newry, I had to skip the visitor centre and move on.

I did have enough time, however, to have a very quick look at the principal building stones and the remnants of the circle of standing stones that once surrounded this monument.

The underlying bedrock in the area is Carboniferous limestone, with Carboniferous sandstone and Silurian rocks, but the large cobbles that can be seen in its front - and are perceived to faithfully reproduce the original source – have been brought in from river terraces and the coast.

The entrance to Newgrange

The highly decorated foundation stones are mainly Silurian greywacke sandstone from the Clogher Head Formation, and the deeply weathered condition of the stones themselves indicate that they are large glacial erratics, which have been found on the ground and not quarried.

Rock Art

Looking very quickly at the standing stones, the purple rocks are obviously volcanic and their origin could only be the Mourne Mountains - of Tertiary age; there are also other large rough blocks of greywacke sandstone and Carboniferous limestone, amongst other kinds of rocks...

A few views of standing stones at Newgrange