Glenulra’s Shifting Shore
Marine Isotope Stage 3, conventionally dated to about 57,000–29,000 years ago, was neither a single uniform winter nor a settled climatic age. North Atlantic temperatures shifted repeatedly between colder stadials and relatively milder interstadials. Those changes affected the reach of glaciers, the position of coasts, vegetation and animal movements. A notional date around 31,806 BCE falls late in this phase, several thousand years before the fullest expansion of the last British–Irish Ice Sheet, generally placed around 27,000–23,000 calibrated years before present.