BIRM-166’s Periglacial Witness
Archived: 8 October 2026
30,122 BCE cannot be reconstructed as a precise year, but falls within a late-MIS-3 interval represented by the Derryvree BIRM-166 organic silt. Deposited between glacial tills in County Fermanagh, it records a locally ice-free freshwater tundra wetland with grasses, sedges, dwarf shrubs, mosses, insects and water plants. Ireland formed an unstable mosaic of ice, periglacial terrain and open habitats before later ice-sheet expansion. Castlepook Cave, County Cork, preserves diverse cold-stage fauna, including mammoth, reindeer and predators, though remains accumulated over time. A marked reindeer bone may indicate human butchery, but sustained occupation remains unproven. Evidence illuminates environmental change, not society.