Derryvree’s Thawline
Archived: 25 September 2026
Abstract
Thirty thousand seven hundred and thirteen BCE is not a meaningful precise Irish date, but broadly relates to later Marine Isotope Stage 3. At Derryvree, County Fermanagh, organic freshwater sediments between glacial tills demonstrate a local ice-free interval, preserving evidence of cold, treeless wet tundra with plants and insects. The BIRM-166 radiocarbon determination has wide calibration uncertainty. Ireland’s ice cover was dynamic before the Last Glacial Maximum. Castlepook Cave, County Cork, preserves remains of diverse Pleistocene mammals, including mammoth, giant deer and hyaena, though deposits span time. No evidence establishes human presence, society or activity in Ireland at this horizon.