Derryvree’s Intertill Biota
Derryvree was exposed accidentally during road works in February and March 1969, when a cutting passed through a drumlin. Beneath the familiar streamlined hill lay a remarkable sequence: freshwater silts and fine sands, including organic mud, caught between two substantial layers of glacial till. The stratigraphy is the fundamental evidence. Ice had previously deposited the lower till; subsequently, at least this locality was free of glacier ice long enough for water, sediment, plants and small creatures to accumulate; later ice advanced again and sealed the deposit under a second till.