Derryvree’s Sedgewater Interval
Archived: 20 September 2026
Abstract
Around 30,999 BCE, Ireland has no recoverable annual history, only sparse evidence from Marine Isotope Stage 3. At Derryvree, County Fermanagh, freshwater organic sediments between glacial tills indicate a locally ice-free interval within a cold, treeless periglacial landscape of sedges, grasses, mosses, pools and marshes. Castlepook Cave, County Cork, preserves remains of reindeer, mammoth, giant deer and other Ice Age fauna, although its mixed deposits cannot reconstruct a single community. A possibly cut-marked reindeer bone may indicate human activity, but remains unconfirmed. No evidence supports permanent settlement, social organisation or named events; the period is best understood as environmental change.