BIRM-166 Between the Tills
Archived: 30 September 2026
30,469 BCE is a notional modern date within Marine Isotope Stage 3, not a recoverable Irish historical year. At Derryvree, County Fermanagh, organic freshwater silts between glacial tills, dated by BIRM-166 to about 30,500 radiocarbon years before present, indicate an ice-free or ice-marginal wetland before later glaciation. Plants, mosses and insects reveal tundra, saturated ground and shallow water. Castlepook Cave in County Cork preserves mixed cold-stage fauna, including mammoth and reindeer. A possibly butchered reindeer bone suggests, but cannot prove, early human visitation. No secure evidence establishes settlement, society, trade or politics. Environmental change and ice-sheet expansion dominate this period.