The Fermanagh Silt Interval
The closest important Irish environmental record is at Derryvree, near Maguiresbridge in County Fermanagh. Road-cutting through a drumlin in 1969 exposed an exceptional sequence: an older glacial till, freshwater silts and fine sands with organic material, and a later till above them. Till is sediment laid down directly by glacier ice. The sequence demonstrates that ice occupied the site, that an ice-free interval then allowed freshwater and organic deposits to accumulate, and that ice later returned.