The Derryvree Sand Lens
Archived: 27 September 2026
At roughly 30,596 BCE, Ireland experienced an unstable later Pleistocene climate rather than a recoverable historical year. Organic freshwater sediments at Derryvree, County Fermanagh, dated broadly to 36,900–31,700 calibrated years before present, show that this locality was temporarily ice-free between glacial advances. Pollen, plants and animal remains indicate a treeless, periglacial tundra wetland with sedges, mosses and dwarf willow. Castlepook Cave, County Cork, preserves bones of mammoth, reindeer, predators and other cold-climate fauna, though its disturbed deposits limit precision. A marked reindeer bone may suggest human butchery, but no securely associated settlement, tools, hearths or population evidence survives. Later glaciation.