The Derryvree Freshwater Lens
Archived: 18 September 2026
Abstract
31,326 BCE is a modern label for later Marine Isotope Stage 3, not a recoverable Irish year. Derryvree, County Fermanagh, preserves freshwater sediments between tills, indicating an ice-free, cold tundra wetland during a broadly dated interval. Castlepook Cave, County Cork, contains MIS 3 remains of reindeer, mammoth, hyaena and other open-country fauna, although disturbed deposits prevent a single ecological snapshot. A cut-like mark on a reindeer femur may indicate early human butchery, but remains contested and cannot prove settlement. Glaciation and changing sea levels obscured evidence. Secure Irish human presence is far later; permanent society is unproven for this period.