Derryvree’s Calibrated Reedbed
The most useful Irish sequence is at Derryvree, near Maguiresbridge in County Fermanagh. Roadworks in 1969 exposed organic-rich freshwater silts and fine sands trapped between two substantial layers of glacial till in a drumlin. The lower till records an earlier ice advance; the sediments above it accumulated during a non-glacial interval; and the upper till shows that ice later returned or advanced across the district. This sequence is unusually precious because subsequent glaciation removed, rearranged or buried so much of Ireland’s earlier Ice Age landscape.