Marine Isotope Stage Three
Archived: 8 September 2026
Abstract
Around 31,972 BCE, approximately 33,900 cal BP, Ireland lay in the later Marine Isotope Stage 3, as climate deteriorated before the Last Glacial Maximum. Lower sea levels altered coasts and potential connections with Britain and Europe, while open tundra-steppe supported diverse Ice Age fauna. Castlepook Cave preserves remains including mammoth, giant deer, reindeer, hyaena and Arctic fox, though redeposition and revised dating prevent precise reconstruction. No securely dated human site exists from this period. Possible cut marks on a Castlepook reindeer bone may indicate an early visit, but remain unconfirmed. Later glaciation destroyed or obscured much evidence, leaving caves archives.