Derryvree’s Sedge Archive
Archived: 16 September 2026
The retrospective date 31,538 BCE denotes a broad Marine Isotope Stage 3 interval, not a documented Irish year. At Derryvree, County Fermanagh, freshwater organic silts between glacial tills, dated roughly 36,900–31,700 cal BP, preserve a treeless periglacial mosaic of sedges, mosses, herbs and shallow water during an ice-free episode. Castlepook Cave, County Cork, contains Pleistocene fauna, including mammoth, reindeer, giant deer and predators, accumulated over long periods. A marked reindeer femur may indicate stone-tool butchery by people, but cannot prove settlement. Ireland was volatile and intermittently habitable before later extensive British–Irish Ice Sheet expansion, while evidence remains fragmentary and uncertain.