BIRM-166 Organic Interbed
Archived: 7 October 2026
Around 30,167 BCE, Ireland’s history is reconstructed from environmental evidence rather than recorded events. At Derryvree, County Fermanagh, organic freshwater deposits between glacial tills, dated broadly to this interval, reveal tundra vegetation, pools and severe periglacial conditions during an ice-free phase. Castlepook Cave, County Cork, preserves diverse cold-stage fauna, including mammoth, reindeer and giant deer, although its mixed deposits span a long period. A marked reindeer bone may indicate human carcass processing, but remains unconfirmed and does not demonstrate settlement. Changing ice margins, sea levels and regional conditions shaped a fragmented Late Pleistocene landscape across the island and through time.