Ireland’s Ice-Sheet Build-Up
Archived: 19 September 2026
At 31,170 BCE, Ireland lay in the climatically unstable later Marine Isotope Stage 3, approaching expansion of the British–Irish Ice Sheet. Precise local conditions cannot be reconstructed: radiocarbon dating provides calibrated ranges, while glaciation erased much earlier evidence. Models suggest regional ice development, becoming extensive later. Southern caves, especially Castlepook, preserve remains of fauna including reindeer, mammoth and hyaena, but mixed deposits and revised dates prevent their attribution to one year. Possible tool damage on a reindeer bone is inconclusive evidence of early people. Secure human evidence is far later, leaving environmental change and uncertainty as this period’s principal record.