Derryvree Lake
Archived: 9 September 2026
At the notional date of 31,895 BCE, Ireland lay within the climatically unstable Marine Isotope Stage 3, before maximum glaciation. Its ice sheet, coastlines and habitats changed markedly across Ireland, precluding a precise national reconstruction. Buried lake sediments at Derryvree, Fermanagh, dated broadly to 36,900–31,700 years before present, demonstrate freshwater and sparse tundra-steppe life during an ice-free interval. Castlepook Cave, Cork, preserves MIS 3 fauna including reindeer, mammoth and predators, though not necessarily contemporaneous. No secure human settlement exists. A possibly tool-marked reindeer bone suggests provisional human activity. Radiocarbon calibration, stratigraphy and environmental proxies provide evidence, but retain substantial uncertainty.