Ireland at the Ice Margin
Ireland was not simply a timeless white wilderness throughout the whole Ice Age. The climatic sequence was uneven, and the growth of the final great ice sheet was a process, not an instantaneous conquest of the island. Evidence from organic deposits sealed beneath till at Derryvree and Greenagho in County Fermanagh indicates that north-central Ireland had been ice-free until at least about 34,000 years ago. A synthesis of the evidence consequently places the principal build-up and expansion of the last Irish Ice Sheet between about 34,000 and 24,000 years ago. The numbered year in this article sits at or very close to the beginning of that long transition.