A Place for the Heathlands

The heathlands of northern Europe were vital sources of fuel, building materials, and grazing lands in the first millennium BC, closely intertwined with human activity. Recent archaeological investigations into red-coloured settlement pits in east Jutland have uncovered evidence of a complex interplay between human activities, heathland resources, and grain-processing technologies. This contribution examines the potential role of peat, including heather-rich peat, in grain-drying activities, offering insights into the dynamic relationship between human settlement practices and heathland environments during the first millennium BC. By focusing on the pits at Løgten Østervej and comparing them with similar findings from Viborg, this study highlights how heathland resources were integral to sustaining early agricultural communities.

Settlement pits are a familiar feature to archaeologists working in the northern European lowlands. These pits, often associated with settlements, are found in various locations – both within house plots and as isolated concentrations across the landscape in what are known as offsite places. They appear to be particularly numerous during the centuries around the middle of the first millennium BC.

The pits are located in a variety of landscape types, from marginal sandy heaths to wetlands and clay-rich soils. They vary widely in size, depth, and the materials they contain, including differences in colour and texture. This variability, coupled with the lack of regularity, has often led to interpretation of the pits as collection pits, initially dug into clayish subsoil and later used for waste disposal. As a result, they are frequently studied only superficially.

However, these pits hold the potential to offer valuable insights into the people of the time, their relationship with the landscape, their daily practices, and possibly even their rituals and perceptions. In the last ten to fifteen years, significant red and greasy layers have been observed in pits in east Jutland and around Viborg. While these findings have not been extensively published, it is likely that such layers are more widespread. This contribution aims to provide an initial interpretation of these red layers, and to explore their potential significance.

In 2012, traces of settlement activities from the period 600–400 BC were discovered over twenty hectares in a hilly moraine landscape at Skødstrup, north of Aarhus.^{1 ( 1 )}
Vinter 2020. The features were concentrated around a fossil stream and along the edge of two small wetland areas in which a thin layer of peat was still preserved. This contribution will focus on excavation fields 1–4 from this site.

In excavation field 1 (Fig. 1), a three-aisled house with four sets of roof-supporting posts was uncovered. To the north of the house, a fossil stream with cultural layers along the edges was identified, some of which exhibited a distinct red colouring. Pottery from this area dates to 600–400 BC. Scattered pits around the house and the stream contained red-coloured fill. Two of these red pits were ¹⁴C dated to 600–400 BC. The house itself was ¹⁴C dated to 844–806 BC (based on two samples), while a third sample dated to the third millennium BC. All samples were from charcoal, which likely does not relate directly to the house but instead originates from earlier clearing phases at the site.

Excavation field 2 was also dominated by a fossil stream with a red-coloured cultural layer along its northern side (Fig. 2). Pottery from this culture layer dates to 600–400 BC. Scattered pits in the surrounding area, many with red-coloured fills, were also noted. Two of these pits were ¹⁴C dated to 564–488 BC and 542–398 BC, suggesting they were contemporary with each other.

Excavation field 3 contained only a few pits. These were examined, but not ¹⁴C dated (Fig. 3). Excavation field 4 featured a large landscape depression containing significant quantities of ceramics and animal bones. On both sides of the depression, a three-aisled house was found with three and four sets of roof-supporting posts. These houses were ¹⁴C dated to 648–547 BC and 760–476 BC (averages of three samples each). Near the houses, several red-coloured pits were identified, one of which was ¹⁴C dated to 541–412 BC (average of two samples), nearly contemporaneous with the houses.

The pits and houses at this site appear to have been deliberately placed in relation to each other, suggesting they represent three contemporary farms with various associated settlement activities. These activities include peat cutting, animal slaughter, clay extraction, and waste disposal. This raises the question whether a more detailed study of the pit contents could provide further insight into the daily practices of the farm – the question that formed the basis for further study.

From the outset, a key part of the research strategy was to excavate and document a large number of pits, focusing on stratigraphy, depositional conditions, artefact content, and plant macrofossil analysis. The goal was to determine the function of the pits and the significance of their various layers.

A total of fifty pits were examined, and between one and nine soil samples were taken from 41 of them. The samples were collected from 28 pits with red layers and 13 without. Out of 153 samples initially screened, 62 were selected for plant macrofossil analysis, which involved identifying and counting different charred plant remains. The selected samples were from 26 distinct pits.

Comparing the anatomy of the pits, both in cross-section and surface, it quickly becomes evident that there is as much variation in pit design as there are pits themselves. The largest pits extend up to 4 metres in length, with the deepest reaching 150 cm below the surface. The cuts in the sides and the shape of the bottom also show considerable variation (Figs. 4–10).

Determining the exact function of the pits is almost impossible, with the exception of nine cooking stone pits and two sacrificial pits containing whole clay vessels. Only two pits could be classified as wells, with a water-deposited bottom layer. Despite thorough excavation, traces of specific activity layers within the fill layers were observed only in one pit, where a heat-affected furnace bottom was identified. The ceramic material in the individual pits was highly fragmented, evidenced by the edge sherds.

In deeper pits, there seems to be a tendency for the lower layers to be stone-filled, greyish, and sterile. These lower layers generally have no or very few macrofossils. This aligns with the interpretation of these pits as clay collection pits in which stones were left behind and mixing with cultural soil was avoided.

Several interesting trends emerged from the macrofossil analysis from the fill layers, particularly those with red coloration. All samples selected for macrofossil analysis came from pits containing red layers, though not exclusively from the red layers themselves. It was observed that most of the grain found in the red layers was clean, with few weed seeds. The grain species identified were naked barley (Hordeum vulgare var nudum), bread wheat /durum wheat (Triticum aestivum ssp. aestivum/Triticum turgidum ssp. durum), and emmer/spelt (Triticum turgidum ssp. dicoccon/Triticum aestivum ssp. Spelta).

Another notable finding was the unusually high number of charred seeds from various wetland plants, such as water sedge (Potamogeton sp.) and yellow seed star (Thalictrum flavum), but also the likely wetland-indicating plants of genus buttercup (Ranunculus sp.) and star sedge (Carex sp.). Additionally, heather stalks (Ericaceae) were found, which are rare on heavy clay soils in east Jutland but can occur in bog vegetation. Seeds from wetland plants appeared in over 75% of the samples from red layers.

Key elements identified in the study of the pits include the presence of cleaned grains, wetland plants, and the distinct red colour in the fill layers. These findings formed the basis of the hypothesis that the red layers originate from the burning of bog peat.

Several indicators support this hypothesis. First, seeds from wetland plants, which typically thrive in bogs, were identified in the macrofossil analysis. Additionally, accounts documented from elderly individuals who recall using bog peat for heating during the second world war describe the production of red ash, which closely resembles the red coloration found in the pit layers. Finally, the early first millennium BC is known for extensive peat extraction, evidenced by peat pits in bogs and ¹⁴C dating of T-shaped peat spades.^{2 ( 2 )}
Jensen 2003, 188.

To test this hypothesis, a burning experiment was conducted using peat from a bog located just 700 metres from Løgten Østervej. After burning the organic material, the residual product was a collection of red iron oxides, supporting the idea that the red coloration in the pits originates from bog peat.

The presence of cleaned grain suggests that peat may have been used in grain drying, a process that would have prevented the grain from rotting. Alternatively, the grain may have been roasted for malting, a step in beer brewing in which germination is halted. Different types of malt barley are produced depending on the drying temperature.

The macrofossil analysis revealed grains from wheat, naked barley, and barley covered with chaff. It remains unclear whether these cereal types appeared individually or mixed in the samples. Since the red layers are likely refuse from multiple activities, a mixture of grain species is expected. As wheat and barley were grown during the same period, it is plausible that they were dried separately but that charred remains of both would be deposited together in the pits.

Additional evidence comes from similar red-layered pits discovered at sites around Viborg, where archaeologists have also linked these layers to peat burning.^{3 ( 3 )}
Mikkelsen 2011, 8

Interestingly, heather stalks are more prevalent in the pits at Viborg than at Løgten Østervej.^{4 ( 4 )}
Personal communication, Mikkel Keldsen, Viborg Stiftsmuseum. This observation suggests that the red coloration could still be attributed to the bog peat, but with a higher content of heather. By the first millennium BC, large heathland areas had already developed in this region. While pollen diagrams specific to these sites have not been produced, historical maps from 1880 confirm the presence of heathland, and other parts of central and northern Jutland also show a spread of heather during this period. Historical accounts also document the widespread use of heather peat as fuel, particularly for lime burning. While the drier parts of the heath could have supplied peat, it is likely that wetland heath areas also played a significant role in providing peat for grain drying and malting.

The findings from Løgten Østervej reveal how the heathlands were a crucial element in sustaining settlement activities during the first millennium BC. The evidence of bog peat and heather use for grain drying shows how these communities adapted to their environment, and demonstrates the significant role that heathland resources played in their daily lives. The presence of red-layered pits, cleaned grains, and wetland plant macrofossils points to the deliberate exploitation of both drier and wetter areas of the heath. These findings align with broader historical accounts of heather and peat use, reflecting a long-standing tradition of integrating heathland resources into human subsistence practices.