Derryvree’s Ice-Free Interval
Archived: 21 September 2026
30,943 BCE denotes no dated Irish event but a late Marine Isotope Stage 3 environmental interval. Derryvree, County Fermanagh, preserves freshwater silts between glacial tills, demonstrating an intervening cold, largely treeless wetland of pools, sedges, herbs, mosses and exposed ground, rather than continuous ice cover. Castlepook Cave, County Cork, records animals including mammoth, reindeer, giant deer, bear, wolves and hyaena, though remains accumulated over long periods. A possibly cut-marked reindeer bone offers limited evidence of human activity, not settlement. Changing ice, sea levels and routes shaped a landscape before expanding ice sheets transformed habitats and subsequently obscured evidence from view.