Atlantic Ice Sheet Growth
Archived: 8 September 2026
At about 31,991 BCE, Ireland lay within the climatically unstable later Marine Isotope Stage 3, before the Last Glacial Maximum. Growing ice, lower sea levels and changing coastlines transformed habitats and possible access routes, though any land connection with Britain remains uncertain. Castlepook Cave in County Cork preserves key evidence: reindeer, mammoth, giant deer, lemmings, predators and other fauna indicate varied cold open environments. A cut-marked reindeer bone suggests possible Upper Palaeolithic human activity, but cannot prove settlement or continuous occupation. Later glaciation destroyed evidence. Consequently, this period is understood through imprecise dating, cave deposits and reconstruction, not year-specific history.