Crag Cave’s Thaw Signals
Archived: 17 September 2026
31,408 BCE is a modern nominal date, not a recoverable Irish year. During climatically unstable Marine Isotope Stage 3, Ireland contained varying ice, tundra wetlands and occasional milder conditions. Derryvree, County Fermanagh, preserves freshwater sediments indicating treeless, seasonal, periglacial habitat with plants, insects and pools before later glaciation. Crag Cave calcite shows intermittent above-freezing water circulation in south-west Ireland. Castlepook Cave’s fauna includes reindeer, mammoth, giant deer, carnivores and hyena, although deposits span millennia. A possibly stone-cut reindeer bone may indicate human butchery, but cannot prove occupation. No securely dated settlements, tools, institutions or practices are known; evidence remains fragmentary.