Derryvree’s Threeleaf Basin
Archived: 7 October 2026
About 32,000 calibrated years before AD 1950, Ireland lay within the climatically unstable Late Pleistocene. Derryvree, County Fermanagh, preserves freshwater organic sediments between glacial tills, demonstrating an interval of ice-free, treeless wetland amid advancing ice. Its plants indicate sedges, mosses and hardy herbs in tundra-like, periglacial conditions. Cave remains show that cold-adapted fauna, including reindeer, giant deer, mammoth and hyaena, reached Ireland during wider MIS 3, though not necessarily together. A potentially cut-marked Castlepook reindeer bone suggests, but does not establish, Upper Palaeolithic human presence. Evidence supports environmental change and episodic animal movement, not settlement, society, trade or recorded events.