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Choose a route into Ireland’s past: follow the newest additions, find a particular year or subject, or browse every available period.
Welcome to Emerald Archives
Emerald Archives presents Ireland’s story one reference year at a time, from the deep prehistoric past to the modern era. Each article explores the evidence, people, places and developments associated with a particular year and places them within their wider historical setting. The collection brings together archaeology, politics, society, religion, culture, conflict, everyday life and changing landscapes in one continuously expanding timeline. New articles appear here as the archive grows. You can also explore the full Irish History Timeline, search the archive directly, or use Explore to move through the collection by period and subject.
Start Exploring
Choose a route into Ireland’s past: follow the newest additions, find a particular year or subject, or browse every available period.
30320–30311 BCE
Mammoth Cave’s Open Ground
The most useful Irish environmental archive close to this broad horizon is Derryvree, near Maguiresbridge in County Fermanagh. Road works cut through a drumlin and exposed organic-rich freshwater silts and sands caught between two glacial tills. The order of layers is decisive. An earlier glacier deposited the lower till; water, plants and organic detritus accumulated during a subsequent non-glacial interval; later ice deposited the upper till and sealed the deposit. This is strong evidence for local environmental change, though not a complete picture of the entire island.
Derryvree’s Periglacial Muskeg
This was the Late Pleistocene, in the later part of Marine Isotope Stage 3, during the last glacial cycle. Ireland was not yet simply the uniformly ice-covered island often imagined from pictures of the Last Glacial Maximum. The full maximum of the last British–Irish Ice Sheet came later, broadly during Marine Isotope Stage 2. Yet neither was Ireland a benign refuge. Ice sheets had already grown and fluctuated around the country; their margins advanced, retreated and reorganised in response to abrupt North Atlantic climatic changes. Different regions could therefore have experienced very different conditions over comparatively short geological intervals.
BIRM-166 Freshwater Chronology
In archaeological and geological practice, “before present” means before AD 1950. Thus 30,318 BCE corresponds approximately to 32,267 years before present. Yet even that conversion must not be mistaken for an ancient date written into the ground. Radiocarbon ages are not calendar years, because the amount of radioactive carbon in the atmosphere has varied through time. They require calibration, and beyond roughly 30,000 years ago their uncertainties become especially substantial.
BIRM-166’s Menyanthes Seed
Derryvree was revealed accidentally during roadworks in 1969, when a cutting passed through a north-east–south-west drumlin. Beneath the familiar rounded glacial landform lay two substantial sheets of till: stony sediment deposited by ice. Between them were fine sands and organic freshwater silts. The sequence is important because it records change rather than a single frozen landscape. Ice had advanced across the locality, then a depression held water and organic material accumulated, and later ice overrode or sealed the deposit beneath a new layer of till. The sediments therefore demonstrate an interval when this part of Fermanagh was locally ice-free; they do not prove that all Ireland was ice-free at once.
Hyenahall’s Vanished Fauna
The closest important Irish environmental sequence is at Derryvree near Maguiresbridge, County Fermanagh. Roadworks in 1969 exposed a drumlin cut through by two separate deposits of glacial till. Between them lay freshwater silts, fine sand and organic matter. The lower till proves that ice had earlier occupied the locality; the intervening sediments show a later period in which open water and vegetation existed; the upper till records renewed glacial influence or ice advance. This order of layers is firmer evidence than any attempt to turn it into an annual timetable.
