Maguirebridge Mossland
Marine Isotope Stage 3, broadly dated to about 57,000–29,000 years ago, was neither uniformly frozen nor climatically stable. Greenland ice cores and North Atlantic records show repeated abrupt changes over centuries and millennia. Ireland lay on the western edge of that North Atlantic world, where temperature, precipitation, vegetation, sea level and the position of glaciers could alter substantially. Around the notional date used here, the great maximum expansion of the last British–Irish Ice Sheet still lay in the future: evidence from land and sea places the principal Late Midlandian maximum broadly after about 27,000 years ago, with many Irish offshore ice margins reaching their greatest extent later still.