But, despite the less-than-summery conditions, the excavation went extremely well, and like any good dig, the archaeologists left with as many new questions as answers as to what went on at the Iron Age site.
A few weeks back, all eyes were firmly on the “well” beneath the broch.
The water from the outer chamber was pumped out and, as suspected, revealed a set of very silty stairs leading down into the rock-cut chamber.
However, a full excavation of this feature will have to wait for a future season — not only due to the complexity of investigating the subterranean chamber but also for safety reasons.
Staying underground, a discovery last week could put to rest the idea that earth-houses — known elsewhere as souterrains — had a practical domestic role.
When the broch at The Cairns was abandoned and filled with rubble — sometime between AD84 and AD210 — an earth-house was carefully constructed to incorporate the broch entrance.
Site director Martin Carruthers, of Orkney College, explained previously: “The decision to reuse the broch entrance was intentional, and seems to have been in some way significant — it was not just the expedient use of a convenient space.
“At the point where the souterrain was being constructed it was very, very close to the time that the broch had been abandoned. They had deliberately filled in the interior and exterior spaces of the broch, mounding up material on the outside — essentially turning what had been a freestanding building into a large mound.
“Just one feature of the original broch remained accessible within that mound — the entrance, that had now been incorporated into the souterrain.”
He added: “To these people, I suspect, the past was a domain hidden in mounds and knowes. I think that many an Iron Age person was acutely aware of ruins — ruins that were already ancient to them — inside these mounds. Were they attempting to create a link to those that had gone before? It’s entirely possible that they extended the sense of the ancient to ‘their own’ remains.”
The bulk of Orkney’s earth-houses were “investigated” by antiquarians in the 19th century, who assumed that what they thought were overhead houses meant the underground chambers had to be purely domestic — usually storage.
But just like the “wells” found under brochs, this explanation has never really satisfied. Why go to all that trouble?
Prior to his work at The Cairns, Martin spent three years working on the Windwick earth-house, a short distance away. From this, he feels that earth-houses had more to do with ritual — and in particular the dead.
He believes the underground chambers were related to rites of passage. An initiation, or trial chamber, for example, used for occasions such as coming-of-age rituals.
Anthropological studies have shown that these types of rituals often involve ordeals, such as sensory deprivation or fasting. Combined with this, did the underground chambers represent some sort of link to the dead — or ancestors?
At The Cairns last week, an unroofed portion of the entrance passage was found to incorporate a substantial upright slab set into a side wall, with the wall rebated behind on the inner end, closest to the roofed portion of the passage.
“If this rebated section was intended to house a door, then this door could only be opened and closed from the inside,” said Martin.
“This adds fuel to the debate about what these souterrains were for, as it means that securing the door was something that could only be done with someone inside.
“If simple, underground, cellar-like storage is envisaged as a function for souterrains, then it seems unlikely in the extreme that it would be desirable to have a person inside the structure before you could close the door!”
Down at the Windwick souterrain, pits cut into the floor of the above-ground structure contained cremated human remains. There were also cremation deposits, possibly human, incorporated in the souterrain chamber’s roof.
Broken querns and rubbing stones were found in the underground chamber, which led to the theory that rough, cremated remains were being ground into finer particles before their deposition. The querns used for this process then appear to have been deliberately broken.
Intriguingly, this year, a saddle quern and a quern rubber were found to have been deliberately incorporated — placed side-by-side, on their sides — in the clay forming the broch floor.
But, while the querns in the Windwick souterrain were undoubtely related to death, the ones in the broch probably represented the opposite.
Martin said: “I would say, in the parlance of archaeology, that these were part of a deliberate and structured deposit, and I’d go as far as to say that this pair of life-giving items — previously used to grind out flour for the daily bread — are a ritual deposit; I’d guess designed to ensure continued fertility for the broch household.”
Looking back over the 2015 excavation, Martin said he was amazed and delighted by what the team had managed to accomplish.
“At the beginning of the season, I don’t think I’d have thought we’d find out half as much about the site, nor would I have anticipated the wonderful finds that have come out of it — both artefactually and in terms of the wonderful features.”
Last year’s work in Trench M hinted that it contained a portion of the great ditched enclosure that surrounded the site, so was a focus of work this season.
Martin said: “Trench M partly answered our main research question this year — where is the great enclosure ditch and what is it like?
“I was not expecting the ‘gully’ — as I now call the feature on the south-eastern side of the trench — to turn out as shallow as it is.
“It’s over a metre in depth, but does not strongly resemble the geophysical signature for the ditch, except perhaps in terms of location.
“What I think is going on is that the ditch in this section — away from the entrance and the rear portions of the broch ditch — is a much more modest affair.
“Often the front and back portions of the enclosure ditches are singled out for more embellishment and depth, making them appear more monumental and grand.
“Alternatively, the ditch itself, so clear on the geophysics just beyond Trench M, may be doing something radically divergent by the time it reaches Trench M and could be further up the slope. However, we will have to wait for a future season to test these hypotheses.”
Just as at sites such as Gurness, later settlement and activity spilled out over the infilled ditch. At The Cairns, Trench M revealed a wealth of evidence of craftwork — particularly metalwork.
With around 60 fragments and whole moulds, the assemblage from The Cairns is one of the largest and best preserved found to date. This, said Martin, will tell us a lot about the inhabitants’ craft, skills, technology and tastes.
He added: “The continued discovery of beautiful bronze working moulds, plus the surprising discovery of what appears to be a copper-working furnace, highlight that we are going to have a wonderful story to tell about metalworking during this period.
“There were craftspeople at The Cairns, at least in one stage, who were remarkably skilful and confident in their own craft. They were producing items of bronze jewellery that are identical to artefact types found throughout Atlantic Scotland and parts of Ireland during the Middle Iron Age.”
Overlying the rubble that remains inside the broch, the Late Iron Age post-broch settlement — made up of at least two large houses — is particularly interesting.
“This year, work on some of the hearths in Structure B has carried on, and it was from one of these that my favourite and most exciting finds came from.
“The animal burials partly deposited under the hearth are fascinating. There were two substantially articulated animals, plus fragments of a possible third, deliberately deposited under the hearth — presumably just before the construction of the hearth and the establishment of a new stage in the life of Structure B2.
“They are going to be fascinating for the information that is hopefully contained in them — age, butchery, definitive species, radiocarbon dates, etc. But it really is the context that makes them so important, as they look likely to join the growing number of votive-style deposits of animal bone found from Iron Age sites.
“It will also show, very clearly, that during the post-broch Iron Age period that such ‘ritual practices’ remained a part of the rich social lives of the community.”
Inside the broch, the excavation of successive floor deposits has the potential to answer many questions surrounding life in the Iron Age towers.
Martin explained: “We found that there were formally laid, thick, orange clay floor deposits laid down to act as the surface upon which people inside the broch were walking and working.
“These were surmounted by a black greasy, unctuous material, and then that this layering was repeated at least one further time.
“The black organic-rich matter has to be compacted occupation material, building up on the orange clay floor during the use of the broch. This shows that we have well-preserved and, hopefully, highly informative deposits within the broch.
“Overall, these floors and deposits are really going to help us answer one of our main research questions — what were brochs actually used for?
“Other sites have yielded some of the same sorts of deposits, but our ultimate intention is to excavate the entire series floor and occupation deposits — from the earliest through to the very latest and across the entire floor area.
“We’ll subject these to all the rigours of modern scientific archaeology and soil-science, as well as to the social theories of inhabitation. And this will be largely a first for broch studies.
“The beautifully vivid, well-preserved floor deposits that we have encountered this year are an important indicator that our aim ought to be achievable and very, very worthwhile.”
- Martin would like to thank Orkney Islands Council, ORCA, University of the Highlands & Islands, University of Stirling and landowner: Charlie Nicholson and family for their support of the excavation.