The Derryvree Silt Lens
Archived: 16 September 2026
Labelled 31,589 BCE, this Late Pleistocene interval cannot be reconstructed as a recorded year but through environmental archaeology. Organic silts at Derryvree, County Fermanagh, lying between glacial tills, indicate a temporary ice-free freshwater tundra of sedges, mosses, herbs and cold-adapted plants, dated broadly to 36,900–31,700 calibrated years BP. Greenagho provides comparable regional evidence. Expanding ice sheets nevertheless made conditions transitional and increasingly glacial. Cave remains at Castlepook demonstrate wider Ice Age fauna, including reindeer and mammoth. A possibly cut-marked reindeer bone may indicate fleeting human activity there, but disturbed contexts and absent occupation evidence preclude claims of settled Palaeolithic society.