BIRM-166’s Broad Horizon
Archived: 18 September 2026
31,301 BCE is a modern label within MIS 3, not a recoverable Irish year. Derryvree, County Fermanagh, provides evidence: organic freshwater sediments between tills, dated by BIRM-166 to 36,900–31,700 calibrated BP, record an ice-free interval before glaciation. Tundra wetlands supported cold-adapted plants and insects. Castlepook Cave, County Cork, preserves MIS 3 fauna including mammoth, giant deer, reindeer and hyaena, indicating varied open habitats. A possibly cut-marked reindeer bone suggests, but does not establish, human presence. No settlement, institutions, ritual, agriculture or continuous occupation is evidenced. The period is best understood through uncertain ranges, changing ice margins, ecosystems and transient visitors.