Awbeg’s Reindeer Crossing – Emerald Archives

Dateline

31,637 BCE is a modern label placed on a time far beyond the reach of written history. No community in Ireland counted years in this way, and neither radiocarbon dating nor glacial stratigraphy can isolate an event, individual or season within one calendar year so remote. The responsible historical frame is therefore broader: roughly 33,600 calendar years before present, within the unstable cold conditions of Marine Isotope Stage 3, part of the last Ice Age. For Ireland, the evidence comes not from settlements or chronicles but from cave bones, buried wetland sediments, pollen, plant remains, insects and the geological traces of advancing ice.

A Date Within Broad Ranges

Calibrated dating is essential to this subject. Radiocarbon laboratories measure remaining radioactive carbon and produce a radiocarbon age; that result must then be calibrated against independently established atmospheric records. At depths of more than thirty millennia, the resulting ranges can be wide. A useful northern Irish sequence at Derryvree, near Maguiresbridge in County Fermanagh, produced a determination of about 30,500 ± 1,100 radiocarbon years before present from organic sediments. Its calibrated span covers several thousand years, broadly about 36,900–31,700 calendar years before present. The notional year 31,637 BCE falls within the wider environmental interval that this deposit can illuminate, but cannot be pinpointed within it.

That limitation matters. Ireland around this time was not frozen in one uniform state, nor can a single deposit speak for every coast, upland or valley. Climate during the middle part of the last glacial cycle fluctuated sharply. Ice masses expanded and contracted; local conditions depended on elevation, exposure, snow cover, drainage and distance from the Atlantic. The later Last Glacial Maximum, when the British–Irish Ice Sheet reached its greatest overall extent, still lay ahead. Around this date, some parts of the island could support animal life and tundra vegetation during milder intervals, while other areas were affected by severe periglacial conditions or ice.

Derryvree Between the Tills

Derryvree is especially valuable because its freshwater sediments were sealed between two bodies of till, the stony debris laid down by glacier ice. Roadworks exposed silts and fine sands containing a striking assemblage of biological evidence: pollen, seeds, other plant macrofossils, mosses and insects. Later glaciation covered much of Ireland, eroding or rearranging older surfaces. The survival of such a sealed deposit gives a rare view of a landscape that was subsequently concealed beneath ice-derived material.

The evidence indicates open, treeless country rather than anything resembling later Irish woodland. Sedges, mosses and hardy herbaceous plants grew in wet ground beside shallow water. Finds including bogbean and water-milfoil point to freshwater habitats, while dwarf willow, mountain avens and other cold-tolerant plants indicate tundra-like surroundings. Insects and mosses add texture to this reconstruction. The landscape has been described as muskeg: waterlogged, peaty ground, broken by pools and vegetated margins, subject to frost and short growing seasons. This was not necessarily a featureless white wilderness. In a favourable season, low vegetation and wetland plants could be productive, but it was an exacting world of frozen ground, limited shelter and rapid environmental change.

Such evidence is direct evidence for organisms and sediments, not a photograph of daily life. It does not identify a particular lake shore in 31,637 BCE, nor prove that all Ireland shared the same plant cover. Yet it firmly corrects two misleading pictures: an island wholly entombed under ice at every moment of the period, and a familiar green, wooded Ireland awaiting human farmers. The available evidence instead favours a patchy cold-stage environment in which open vegetation, freshwater pockets and seasonal animal movement were important.

Castlepook’s Animal Archive

In north County Cork, the limestone caves at Castlepook, in the Awbeg valley near Doneraile, preserve another kind of archive. Excavations conducted chiefly in the early twentieth century recovered a large collection of animal remains. The assemblage includes woolly mammoth, reindeer, giant deer, brown bear, wolf, Arctic fox, mountain hare, collared lemming, Norwegian lemming and spotted hyaena. Not every species need have occupied the cave at the same time: old excavations did not record deposits to modern standards, and cave floors can combine material brought in by animals, water, collapse and people over long periods. Nevertheless, the collection demonstrates that Ireland supported, at intervals in the Late Pleistocene, a fauna far different from that of recent centuries.

Castlepook is particularly important for dating the broad pre-maximum cold stage. The Irish Quaternary Fauna Project used accelerator radiocarbon dating to reassess cave collections and concluded that a wide range of mammals reached Ireland between at least about 45,000 and 20,000 years ago. Subsequent work has also demonstrated why caution is needed: improved collagen purification has shown that some earlier bone dates could be substantially misleading. Individual dates and species lists are consequently best treated as evidence to be continually tested, rather than as a seamless timetable of occupation.

Even with that caution, the ecological implications are substantial. Reindeer and mammoth indicate open feeding grounds; lemmings and Arctic fox point to severe cold; wolves and hyaenas reveal a food web with active predators and scavengers. Hyaenas may have used caves as dens or repeatedly dragged in carcass parts, helping to explain damaged and scattered bones. A cave assemblage therefore records animal movement, predation, scavenging and geological processes as much as it records the place where an animal died. Castlepook was not a village, and it should not be casually described as one.

The Reindeer Femur Question

One Castlepook object is directly relevant to a date in the early thirty-second millennium BCE: a reindeer femur fragment reported as roughly 33,000 years old and carrying a deep mark interpreted by zooarchaeologist Ruth Carden as having been made by a sharp stone edge during carcass processing. County Cork heritage material has presented the find as possible evidence that Upper Palaeolithic people handled reindeer in Ireland tens of millennia earlier than the previously accepted terminal-Pleistocene evidence.

The possibility is important, but the conclusion must remain conditional. The femur was recovered from an historic collection, not from a recently excavated occupation surface with its position, associated tools and overlying deposits recorded in detail. A date on bone establishes when the animal lived and died, not automatically when a surface mark was made. Identifying a cut mark also requires taphonomic judgement: trampling, carnivore activity, breakage, excavation damage and other processes can alter bone. No securely associated hearth, dwelling, stone-tool assemblage, burial, ornament, artwork or repeated butchery floor of this age has been published from Ireland.

If the incision is confirmed as a fresh-bone tool mark and is contemporary with the animal, it would show a remarkably small but consequential human footprint: at least one person used a sharp implement on a reindeer carcass. It would not show whether people killed the animal, found it after a predator’s attack, took meat, hide, sinew or marrow, camped nearby, crossed the island regularly, or remained for more than a brief visit. Still less could it establish a tribe, language, political community or continuous ancestry linking those visitors to later inhabitants. The evidence permits the possibility of transient human incursions; it does not yet establish settled Palaeolithic Ireland.

Society Beyond Recovery

There is no responsible basis for describing political affairs, diplomacy, rulers, territorial boundaries or organised conflict in Ireland at this date. No human settlement is securely known from the period, and there are no records from which to recover names, beliefs or institutions. Likewise, there is no Irish evidence for houses, clothing, family organisation, ritual, art, burial practice, learning or language around 31,637 BCE. European Upper Palaeolithic communities elsewhere made sophisticated stone tools, ornaments and art, but proximity is not proof. Those wider traditions are useful context for what a hypothetical visiting hunting party might have known; they are not evidence that such objects or practices existed in Ireland.

The same restraint applies to economy and trade. The animal record shows resources potentially available in the landscape: large herbivores could yield meat, fat, hide, sinew and bone, while small mammals and birds may have added other seasonal opportunities. But Ireland has yielded no securely contemporary evidence of exchange networks, transport routes or a local economy. The sea level was much lower than today because considerable water was held in ice sheets, altering coastlines and the extent of continental shelves. Yet the precise routes by which animals, and perhaps people, reached Ireland at particular times remain unresolved. Ecological connection with neighbouring lands should not be converted into a confidently drawn land bridge for this exact year.

An Island of Windows, Not Certainties

The most defensible picture is therefore one of environmental windows. During suitable phases, cold-adapted animals reached parts of Ireland and exploited open, wet, treeless habitats. Their remains survived especially in caves and in unusual sedimentary traps, although later ice and erosion removed much else. Derryvree records freshwater tundra and muskeg in Fermanagh; Castlepook records an extraordinary southern fauna and the unresolved possibility of human butchery. Together they show that Ireland was neither absent from the ecology of Ice-Age north-west Europe nor yet a documented human homeland.

For 31,637 BCE, uncertainty is not a failure of history but a fact to be explained. The evidence is fragmentary because the landscape has been repeatedly glaciated, because caves are complex archives and because modern calendar years are much finer than Pleistocene dating can sustain. What can be said with confidence is more modest and more vivid: around this broad horizon, parts of Ireland contained cold open ground, freshwater wetlands and mobile herds and predators. Whether a very small number of people briefly joined that world remains one of the most compelling unanswered questions in Irish prehistory.

Primary Sources

Tags: County Cork, Ireland Year by Year, Late Pleistocene, Marine Isotope Stage 3, Radiocarbon Dating, Reindeer