Summary of site:
In this large area of the central Mourne Mountains, traversed by (west to east) the Windy Gap, White Water and Yellow Water rivers, there are extensive glacial deposits. The village of Attical is close to where the western and eastern rivers merge with the White Water. The deposits take the form of terminal, lateral and medial moraines, largely confined to the valley floors and the low flanks of the neighbouring mountains, but there is also limited evidence of small, short-lived glacial lakes, trapped behind moraines.
At the height of the Midlandian glaciation (Ireland’s last major ice age), large continental ice sheets, centred on an axis in Lough Neagh Basin, invaded the granite massif from the north. The ice passed over the cols and through the valleys and there is evidence of a lobe pushing into the lower White Water valley around the summits from the west. Later, as the climate progressively warmed, the ice was confined to the valleys; mountain glaciers, fed from high snowfields and corries, flowed south and merged in the White Water valley where medial moraines were formed.
Most of the glacial deposits in the area record the retreat phases of these mountain glaciers, including a short episode of re-advance. There was a brief period of lake formation before meltwaters finally breached the confining moraine dams, allowing their waters to drain away about 13,000 years ago.
A fuller account of these moraines is given in site record ‘Attical Complex-Attical Valley moraines’.