Water-Milfoil Between Tills
Archived: 29 September 2026
Around 30,473 BCE, Ireland experienced the unstable Late Pleistocene rather than a datable historical year. Derryvree in County Fermanagh preserves freshwater sediments between tills, showing a local ice-free wetland during Marine Isotope Stage 3. Its plants and insects indicate cold, treeless tundra-like conditions, with seasonal pools and vegetation. This evidence cannot establish island-wide conditions or a precise date. Castlepook Cave documents diverse cold-stage fauna, including mammoth, reindeer and hyaena, but its disturbed deposits span long periods. A possibly cut-marked reindeer bone suggests early human presence, yet does not prove settlement. Later ice reshaped landscapes and obscured evidence; uncertainty remains central.