Derryvree’s Twin Tills
Archived: 23 September 2026
30,815 BCE is a retrospective label within climatically unstable Marine Isotope Stage 3, rather than a date for a known Irish event. At Derryvree, County Fermanagh, twin glacial tills enclose freshwater sediments and organic muds, recording an ice-free, periglacial wetland before renewed glaciation. Radiocarbon evidence dates this interval broadly to the mid-to-later 30,000s calibrated years BP. Plants indicate open tundra vegetation and standing water. Castlepook Cave preserves diverse cold-climate fauna, but mixed deposits prevent a single-time reconstruction. A possibly cut-marked reindeer bone may suggest human visitation, yet no secure contemporary settlement evidence exists. Ireland was entering broader ice-sheet expansion phase.