Derryvree’s Open Fen
Archived: 19 September 2026
The label 31,183 BCE is a modern filing date, not a recoverable event. Derryvree's organic deposits, between glacial tills in County Fermanagh, date broadly to 36,900–31,700 calibrated years BP, showing ice-free conditions during Marine Isotope Stage 3. Plant, pollen and insect evidence reconstruct a cold, open freshwater fen of mosses, sedges and herbs. Other deposits and Castlepook Cave's fauna demonstrate intermittent non-glacial habitats and large mammals, but not contemporaneity. Possible human modification of a Castlepook reindeer bone remains unconfirmed; no secure contemporary settlements or social history exist. Later ice erased much evidence, leaving environmental reconstruction rather than dated human narrative.