Derryvree’s Sealed Fen
Archived: 26 September 2026
Abstract
Derryvree deposit near Maguiresbridge, County Fermanagh, provides environmental evidence for a Late Pleistocene ice-free interval encompassing 30,668 BCE, though no event can be dated to that year. Freshwater silts and organic sediments, sealed between glacial tills, accumulated in a cold, treeless periglacial wetland of sedges, mosses, herbs and shallow pools. Radiocarbon results indicate a broad calibrated range of roughly 34,950–29,750 BCE. Later ice overrode the basin. Castlepook Cave fauna demonstrates episodic presence of Ice Age mammals, but not synchrony. A possibly butchered reindeer bone offers disputed evidence of people; no secure settlement or social record exists. A rare environmental archive.