Fermanagh’s Sedge Marsh
Archived: 18 September 2026
At approximately 33,240 cal BP, corresponding broadly to 31,291 BCE, Ireland experienced the climatically unstable Marine Isotope Stage 3. Ice-free and glacial conditions alternated, while lower sea levels reshaped coasts without guaranteeing land bridges. At Derryvree, County Fermanagh, freshwater sediments dated 36,900–31,700 cal BP preserve evidence of sedges, grasses, mosses and cold-adapted wetland plants in a treeless landscape. Castlepook Cave, County Cork, records a time-averaged fauna including reindeer, mammoth, giant deer, predators and lemmings. Possible cut marks on reindeer bone suggest unconfirmed human visitation. Later glaciation destroyed much evidence, leaving environmental change, rather than recorded society, as this period’s history.