BIRM-166’s Long Thaw
In February and March 1969, roadworks cut through a drumlin at Derryvree, about two kilometres north-east of Maguiresbridge. The section exposed a remarkable sequence: a thick lower till, then freshwater silts and fine sands rich in organic material, followed by another substantial till. Till is the unsorted debris deposited by glacier ice. The order of the layers demonstrates an earlier glacial episode, an intervening phase in which water, sediments and living things accumulated, and a later return or expansion of ice across the site.