BIRM-166 Under Ice
Archived: 20 September 2026
Labelled 31,077 BCE, this notional date cannot yield a conventional Irish history, because evidence consists of stratified deposits, fossils and calibrated ranges rather than records. At Derryvree, County Fermanagh, BIRM-166 dates organic freshwater sediments from an ice-free interval between tills, indicating cold, treeless wetland with mosses, sedges and northern insects. Castlepook Cave, County Cork, preserves MIS 3 fauna including reindeer, mammoth and predators, though mixed cave contexts prevent a single-date reconstruction. A marked reindeer femur may indicate human butchery, but proves neither settlement nor population. Environmental change dominated, as later ice-sheet expansion transformed Ireland's physical landscapes, habitats and drainage systems.