Folds at Loughshinny

Loughshinny is a village in Ireland, about 15 km north of Dublin. This place has a very nice exposure of folded sediments from the late Carboniferous1.

Folded cliff is easy to access but one should really take care to visit the place during low tide. It was high tide when I first arrived to the scene. As you can see, it was hard to take a good photo without getting very wet:

Folds are really spectacular. They have angular hinges and northern limbs are overturned. The mountain building event that is responsible for this deformation is the Variscan orogeny.

Folded sediments are turbidites. Dark layers represent fine-grained mudstone. Lighter layers are somewhat coarser. The whole sequence is calcareous, there are many calcite veins cross-cutting it.

I left the folds at Loughshinny to see other places but I really wanted to take a better picture and see more. So I came back about 6 hours later and the whole scene was very much different. The coastline was several hundred meters away from the cliff and I was able to take many more photos and wander along the coast as long as needed.

These are really crazy folds, the best I have seen so far.

The folds are plunging towards the sea. White veins visible on top of the shale layer are composed of calcite.

Here is a piece of shale from Loughshinny. White is calcite. Width of sample 10 cm.

I paid most of my attention to the rocks but I noticed that something weird is going on in the beach sand as well. If you want to know what it is then take a look at the post I’ve written before: Thousands of sand sculptures.

Here are the coordinates of a car park in case you wish to visit the place: 53° 32′ 49″ N 6° 04′ 45″ W. The folds are a few hundred meters to the southwest.


1. Stillman, C. & Sevastopulo, G. (2005). Leinster (Classic Geology in Europe). Dunedin Academic Press.

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