The Derryvree Freshwater Series
Archived: 16 September 2026
31,611 BCE is a modern approximate label for Ireland during Marine Isotope Stage 3, rather than a recoverable historical year. At Derryvree, County Fermanagh, freshwater silts between glacial tills record an interval of cold, non-glacial conditions before later ice expansion. Mosses, sedges, herbs, insects and aquatic plants indicate open, wet tundra with severe winters, not forest or permanent ice. Faunal remains, including reindeer and mammoth, demonstrate intermittent links with wider European ecosystems. Castlepook Cave preserves contested possible cut marks suggesting human activity, but not settlement. Subsequent Last Glacial Maximum ice reshaped Ireland, preserving evidence of a severe, intermittently habitable landscape.