Derryvree Between Two Tills
Archived: 9 September 2026
At 31,856 BCE, Ireland was in Marine Isotope Stage 3, a climatically unstable later Pleistocene phase rather than a precisely recoverable year. Derryvree, County Fermanagh, preserves freshwater organic sediments between tills, demonstrating locally ice-free conditions before renewed glaciation. Its mosses, sedges, insects and other remains indicate treeless, wet tundra with shallow water, seasonal growth and severe winters. Cave and fossil evidence shows diverse cold-stage animals reached Ireland, although local dates and species distributions remain uncertain. No secure archaeological evidence proves resident humans. Lower sea levels altered landscapes, but expanding Irish ice later transformed habitats, drainage and shorelines across the island.