Derryvree’s Alpine Marsh
Archived: 20 September 2026
31,103 BCE is a label within a Late Pleistocene range, not a datable Irish event. Derryvree, County Fermanagh, preserves organic freshwater sediments between glacial tills, indicating an ice-free, cold, treeless wetland during part of Marine Isotope Stage 3. Mosses, sedges, mountain-avens and bogbean reveal tundra-like, seasonally thawed conditions, while later ice sealed the deposit. Ireland was not necessarily uniformly glaciated before the Last Glacial Maximum, but comprised changing regional environments. Castlepook Cave fauna records cold-adapted mammals and predators over time. A possibly cut-marked reindeer bone may indicate human contact, yet cannot establish settlement, population or activity in any single year.