In The Deep Freeze
Last updated: 25 March 2010
The Quaternary brought a major change in climate. Although thought of as the Ice Age, ice was in fact only present for relatively short periods of time, albeit still amounting to many thousands of years.
The impact on landscape cannot be overestimated. Ice masses thousands of meters thick, moved over the land eroding and re-depositing vast amounts of material. Ice action in many lowland areas formed drumlin belts, particularly in Down and Armagh, while many upland areas were generally smoothed giving the characteristic outline of much of the Mourne Mountains. |  |
 | As ice melted, a range of landforms developed including moraines, marking positions where glaciers halted on their retreat, eskers, formed by rivers within the ice and deltas, where rivers poured into enormous ice dammed lakes. Such features are well seen between Cookstown and Omagh and also in the Dungiven area. |
| While the major determinant of landscape character since the Ice Age has been the impact of human activities, natural processes are ongoing. Changes in relative sea-level has formed the raised beach on which the Antrim coast road has been built, with stranded caves and intriguing stranded coastal landforms near Ballintoy Harbour. The most notable developments have been the growth of coastal dune complexes, as at Magilligan and Murlough and initiation and expansion of lowland and upland peat bogs which can be seen at Garry Bog and Garron Plateau. |  |