Castlepook’s Open Tundra
Radiocarbon measurements do not translate directly into calendar years. They must be calibrated against internationally maintained curves, and uncertainty becomes substantial at this depth of time. A useful local comparison is Derryvree, near Maguiresbridge in County Fermanagh. There, organic-rich freshwater silts and fine sands lay between two tills: deposits left by separate phases of glaciation. The material produced a conventional radiocarbon determination of about 30,500 years before present, with a large error margin; published calibration places it approximately between 36,900 and 31,700 calendar years before present. That broad interval encompasses the modern label 31,852 BCE.