BIRM-166 Freshwater Silts
Archived: 24 September 2026
Although labelled 30,752 BCE, this horizon cannot be reconstructed as a recorded year. Derryvree, County Fermanagh, preserves freshwater silts between glacial tills, radiocarbon dated broadly to 36,900–31,700 calibrated years before present. Plant and insect remains indicate cold, open tundra-like wetlands during an ice-free interval. Similar northern deposits confirm intermittent non-glacial conditions before expanding ice-sheet cover. Caves contain MIS 3 remains of mammoths, reindeer, giant deer and predators, but these animals were not necessarily contemporaneous. A possibly tool-marked reindeer bone from Castlepook suggests human presence around 33,000 years ago, yet settlement remains unproven. Evidence documents fluctuating habitats, fauna and ice-sheet growth.