Lesser Clubmoss Under Fermanagh
The closest important Irish archive is at Derryvree, near Maguiresbridge in County Fermanagh. Roadworks in 1969 cut through a drumlin and revealed freshwater silts, fine sands and organic layers lying between two thick sheets of till, the unsorted sediment deposited by glaciers. The organic deposit produced the radiocarbon determination Birm-166, 30,500 radiocarbon years before present, with a substantial uncertainty of +1,170 and −1,030 years. Its calibrated calendar range is broad: approximately 36,900–31,700 cal BP, conventionally about 34,950–29,750 BCE.