Crag Cave’s Thaw Pulses
Archived: 18 September 2026
31,249 BCE is a modern label for a broad MIS 3 horizon, not a precise Irish event. Ireland experienced unstable cold-stage conditions, with shifting ice, permafrost, meltwater and sparse vegetation before the Last Glacial Maximum. Derryvree’s sediments preserve a treeless freshwater wetland between glacial advances, while Crag Cave calcite indicates episodic thaw and water infiltration in south-west Ireland. Castlepook Cave fauna show cold-adapted mammals, including reindeer, mammoth and hyena, reached the island. A marked reindeer femur may indicate early human butchery, but remains unconfirmed. Changing coastlines allowed ecological connections, though routes remain uncertain; political or cultural history is largely unrecoverable.