The Maguiresbridge Freshwater Lens
Archived: 15 September 2026
Circa 31,673 BCE, Ireland cannot be described through a dated event, but through a variable Marine Isotope Stage 3 environment. At Derryvree, near Maguiresbridge, freshwater silts between glacial tills preserve evidence of ice-free, treeless periglacial wetlands, with mosses, sedges, grasses, herbs and juniper. Castlepook Cave in Cork records mammals, including mammoth, reindeer, giant deer, bears, hyaenas, wolves and lemmings, across many millennia, demonstrating ecological links with north-west Europe. A marked reindeer bone may indicate human butchery, but remains contested. No settlements or social institutions are known. Together, these archives reveal dynamic, intermittently habitable landscapes, later overridden by advancing ice sheets.