Derryvree’s Tundra Testament
Derryvree’s sequence is important because its order is unambiguous even where its dates are broad. A glacier deposited the lower till; an interval without local overriding ice allowed freshwater sediments and organic remains to accumulate; then a later glacier covered the deposit with a second till. The record therefore proves that part of Fermanagh was ice-free long enough for standing or slow-moving freshwater and tundra vegetation to develop before a renewed advance transformed the landscape again.