An Incision at Castlepook
Archived: 17 September 2026
Although 31,501 BCE cannot be dated precisely in Ireland, it falls within climatically unstable Marine Isotope Stage 3. Derryvree sediments in Fermanagh indicate a local ice-free interval with cold, treeless freshwater wetlands between glacial advances, not conditions across the island. Castlepook Cave, Cork, preserves fauna including mammoth, reindeer, giant deer, predators and cold-adapted mammals, demonstrating suitable open habitats. A reindeer femur, possibly cut with a stone tool around 31,000 BCE, may indicate human butchery. However, its disturbed provenance and lack of occupation evidence preclude claims for permanent settlement. Ireland remained a changing Ice Age landscape, perhaps visited by mobile hunter-gatherers.