The UHI Archaeology Institute’s research excavations at The Cairns have now come to an end for this year. With the site safely covered up, it’s time for site director Martin Carruthers to sum up…
In the broch
Well, what a season it’s been, lots of lovely sunshine and just a little rainy weather, most importantly: some amazing discoveries and startling finds!
The major aim of the work in the interior of the broch this year was to explore more of the occupation deposits and features and to prepare for the completion of the broch excavation next season. Progress in the different zones was led by Rick, Amanda, and Chris over the weeks.
In the west and south-east rooms, the work continued to focus around the two big hearth mounds there. In both cases, complex and multi-phase hearths clearly formed the basis for activity in these areas over several centuries of the occupation.
In the west, north, and north-east rooms the natural glacial clay emerged across ever more extensive areas of the base of the broch. This is fantastic news for our work schedule and our realistic ability to complete the excavation next year, having captured 100 per cent of the floor and occupation deposits. These deposits will continue to be one of the most informative elements of understanding what life was like for the broch household 2,000 years ago.
As usual, the west room was rich in amazing artefactual material, including what appears to be two spiral finger rings (they require conservation treatment to be certain) and a bone mount complete with its bone pegs. The hearth itself was accompanied by an ash box – a stone-lined, sub-rectangular feature full of ash scooped, or swept, from the hearth cleanings.
Meanwhile, in the south-east room, the hearth remained complex – an indication of the longevity over which it was the focus of the room and also the fairly frenetic nature of change and modification.
This hearth also had an ash box but, unlike its counterpart (thus far), it was originally created by scooping a large shallow bowl into the clay-earthen floor of the room. To one side of this scoop a stone-lined feature, which may be a large socket for hearth furniture, was framed using two reused saddle querns (querns remained a big theme this year!).
In the north room, we were perhaps a little more surprised to also find a hearth. Traditionally, in British roundhouse and broch excavations the northern areas of buildings often appear to be quite quiet and the suggestion has been made that these were the area of sleep and storage.
However, since last year’s excavations we have been finding lots of artefactual material in the north room of our broch, including significant amounts of decorated ceramics, which we think were often drinking/dining vessels.
This year, Thore found a very clear heat-affected hearth base slab in the centre of the room near to its entrance, very similar to any of the ones previously found in the west room.
This broadens our sense of activities in the broch and it will be very interesting to try to confirm what was being cooked and consumed in the north room given what we have previously found in the west and south-east rooms and their highly distinctive food patterns or inventories.
In the central room, the apparatus of Iron Age heating technology was also forthcoming. Here, at the room’s northern edge, Travis excavated a small three-sided feature of coursed masonry with lots of ashy soils and the remains of a small heat-affected stone base.
This feature, sat between two large upright stones giving it stability, appears to have been an oven or a kiln and it also extends our sense of the activities under way inside the broch. This is especially the case for the unusual central room, with its primary role of facilitating access to the other rooms in the N-W-NE range of the broch. It shows again that activities seem to have taken up every inch of floor space on the ground floor of the structure.
In the north-east room, thick deposits of ash and organic soils with waterlogged wood fragments were excavated by Scott, SJ, and Liz. Dozens of lovely laminations could be seen in the sections of soil as they dug. These will no doubt become lots more, maybe hundreds, of lenses when looked at under the microscope, yielding insights on the nature, tempo, and origins of these ashy soils and how they were deposited.
Importantly, at the base of these ashy soils the natural glacial till emerged. It is the level at which the original broch builders cut into the hillside to create a more level platform for their massive building. The clay surface slopes down slightly towards the east allowing dampness to generally drain towards the area of the broch entrance.
An important finding on this natural was the presence of features that are early in the broch occupation – an early paved surface in the eastern corner of the north-east room and a stone setting of edge-set stones resembling part of the kerbing around some Iron Age period hearths. To some extent, the full significance of these early features, in chronological terms at any rate, may not be apparent until the post-excavation stage of the project.
The recovery of a quern and quern rubber that had been placed on edge next to each other in a foundation context of a little scoop in the natural glacial till suggests the kinds of measures taken in the foundational stages of the broch. The use of old tools that had seen good use, but which were not exhausted or damaged, to initiate the broch gives fascinating insight into the ritualised actions of setting up the powerful broch-house and household who were to live in it.
Finds from the broch this year were also very nice. Three perforated bone mounts came from the south-east, south and west rooms, respectively, and two of these had intact pins remaining, in situ, in their perforations.
The copper alloy spiral rings are more personal jewellery items to go alongside the many glass beads, pin fragments and other bronze rings from this room. These again accentuate how the west room was apparently an important core area for presentation of identities of power and display.
Associated Bone Groups (ABGs) included articulated bones such as the vertebrae from the south-east room or the remarkable deer leg with intact foot bones in the west room. These are really useful in terms of what we call taphonomy – the study of how deposits were formed.
Originally the term related specifically to how animal bones become fossilised but has now been extended to think of all formation processes. Knowing how much confidence we can place on the animal bones and whether a particular animal bone represents the time of its deposition is enormously helpful for things like the integrity of radiocarbon dating. Again, our “Finds officer” on site, Kev, made a big contribution this year, cataloguing and contextualisation of the groups of finds and fauna at all stages as they emerged, were excavated, lifted, and recorded.
Beyond taphonomy, the ABGs are intrinsically interesting when we consider what process could have led up to the moment of their inclusion in the floor/occupation deposits. Why should these large, still at least partly fleshy, pieces of animals be left on the floor of a building while it was still being occupied, creating clutter and the rotting odour?
We know from many other Iron Age houses across Britain that animal carcasses were placed under floors or at the end of the lives of buildings, as well as artefact groups, similar to our querns deposit in the north-east and south-east rooms. Some animal bodies have also been discovered in other well-preserved brochs during their occupation, analogous to those at The Cairns, so there is a clear pattern of such faunal deposits.
The answer as to why, probably relates to periodic bouts of reflooring and modifying the broch. These animal “offerings” mark episodes of change and renewal. At The Cairns we have numerous ABGs and we think they will really assist us in one of our key research aims of exploring the ritual and social lives of brochs.
In the village
Immediately outside the broch, on the eastern side of the site, work in Structure O moved on apace. It was possible to unravel something of its sequence and see how the original Str O wall had been added to (Structure O2) and this ran right over the infilled remains of village building Structure T.
Meanwhile, the early manifestation of Structure O can now be recognised as a likely unroofed, outdoor yard just outside the broch – perhaps even part of a large formal passageway that wound up toward the broch threading past the village buildings. The paving of Structure O included a large drain that seems to run out from under the broch entrance and through the O wall via a well-built culvert at the base of its wall. Again, this shows how Structure O was a contemporary component of the broch-period village.
Drains continued to be a theme of the work we undertook at the front of the broch, with a fine set of drain caps also uncovered running around the foot of the broch in the area south-east of the broch entrance. But not before a fantastic set of deposits, containing lots of animal bone and shell, were excavated from the soils above the drain. These will give us fantastic insights into the food remains of the broch period to go alongside those from the broch interior itself, allowing very useful comparison.
As Holly and her team worked on the Structure O area they also finalised the recording of the souterrain and were able to see that, at the entrance end, to the south, it had a bit more formal extent. This helps us understand the fuller architectural context of the souterrain and fulfilling another of our project research aims.
To the north of the area, the excavation of Structure O wall revealed the full extent of the underlying broch-period village building Structure T. In plan, this building is a curving, cellular building that rests directly against the north-eastern wall face of the broch outer wall. Again, the animal bone and artefactual material excavated from here is an incredibly useful comparison with the broch itself but Structure T will be more fully excavated next season.
Stepping forward a few centuries in time, we also continued working on Structure B2 – one of the wag, or wag-like, buildings built over the western side of the remains of the broch. Last season, the building yielded fragments of engraved Roman vessel glass and the finds this year included lots of pottery, an iron pin and a wonderful, decorated quern of an unusual “side-slotted” type.
A soft floor was found to surround the central hearth of the building and this is a relatively rare survival for the Later Iron Age, so presents us with the opportunity to explore the activities that went on inside the building c.AD300-500.
The final zone of excavation on site this year, lay on the south-east margin of the main trench in an area known as “the Cells”.
Again, Cairns stalwart, Ole, oversaw the work here. A big surprise this season was the depth and preservation of these structural remains, which survive to above average human head height. Even more surprising was the discovery of an intact and still-roofed chamber set within the walls of Structure U1.
Next to the chamber, framed between two large upright slabs was a triple-decker cupboard with beautifully constructed niches, complete with last content (including a coarse stone tool and a large common whelk shell), just as the last human hands to use the cupboard in the Iron Age had left them. We also reached a slabbed floor at its base.
The depth, position, and architectural style of Structure U1 and its cupboard, very much indicate that it was Middle Iron Age in date and very likely a broch-period village structure. Each of the other cellular structures we have uncovered here (U2, U3, and U4) are subsequent modifications and reorganisations of this original building, developing over a period of centuries.
At the latest end of this little sequence is Structure U4, which we also excavated this year, and which was also very well-preserved. The fine masonry of its walls was lovely to see come into clearer perspective as the dig progressed but also, importantly, it resolved into a clay and organics floor and a slab hearth, which we have paused on for this year but which will be 100 per cent excavated and sampled next year to gain more insight into this late Iron Age building and the lives under way inside.
And now for some thank-yous!
I’ll take this opportunity to thank the entire project team across the weeks of the fieldwork, for their unstinting good humour, patience, and enthusiasm. Without them, the site would remain unexcavated, and its only through their sterling efforts that we begin to understand what was going on at the site all those years ago.
This year the public have visited the site as before. We benefitted from large numbers of visitors and they were very generous in their support for the project. Donations will now be spent on important aspects of post-excavation work, such as additional artefact conservation. I would like to thank all the visitors and donors, for allowing us to communicate our findings with them from the site.
Our funding bodies this season included the Society of Antiquaries of Scotland, the Orkney Islands Council Archaeology Fund and the UHI Archaeology Institute.
Finally, I would like to thank Charlie and Yvonne Nicholson, and all their family and friends in South Ronaldsay, for their many acts of assistance and generosity. Our time at The Cairns excavations is made possible, enjoyable, and very amiable, entirely due to their great kindness.
Thank you!
Martin Carruthers
Site director
