A window into Iron Age South Ronaldsay

Dig hints at early fish processing inside broch site


Six years ago, viewing a massive pile of rubble in a field in South Ronaldsay, I raised an eyebrow and wondered how it could be possible to unpick the story of what appeared to be a large broch-like structure.

But another four-week excavation at The Cairns came to a close last week, and our understanding of the enigmatic Iron Age site has come on in leaps and bounds – although, as is often the case, the site has raised just as many questions as answers.

In charge again this year was Orkney College UHI lecturer Martin Carruthers, whose enthusiasm for the project continues to be infectious.

Some of The Cairns excavation team at work on the outside of the broch wall.

Some of The Cairns excavation team at work on the outside of the broch wall.

A tour of the dig site, last Thursday, highlighted just how far the archaeologists have come in their understanding of a highly complex series of structures, dating from the Iron Age right through to the arrival of the vikings.

When it was first uncovered, the massive broch was found to have been filled to the top with rubble — detritus that had to be painstakingly recorded and removed to allow access to the layers of occupation.

But the work is paying dividends and, this year, for the first time, the experts had the chance to excavate one of the last phases of occupation inside the structure.

Martin explained: “This year, we’ve been working on a section of the interior of the broch, and have now reached the occupation layers that lie directly beneath the lowest layer of substantial rubble that filled the structure.

“We managed to get to within reaching distance of the upper occupation deposits last season, so this year we’ve carried on and have been working on the inside, making our way down through alternate layers of rough, flagstone pavements and soft, clay floor levels and charcoal-rich levels.

“We’re still some way off the primary occupation level — that is, the floor surfaces used by the original inhabitants of the structure — but we’re doing a very careful job, because one of the major things we want to do is fully understand the entire biography of the inside of the broch. To do this, we have to be extremely sensitive to every single occupation episode.”

But even though the diggers have reached what would have been the last phase of the broch’s life, the results have been surprising.

Limpet shells and stone tools up against the interior broch wall.

Limpet shells and stone tools up against the interior broch wall.

Of particular interest is the discovery that there seems to have been some fairly intensive handling and processing of fish — something that, until now, has been missing from Iron Age sites. In fact, due to the lack of evidence, it has long been assumed that fishing was not a major concern during the period.
Martin said: “What we’ve got this year is some really interesting stuff coming out of the upper floor deposits in the broch, including, almost for the first time on a major Iron Age site, good evidence for fairly intense activity revolving around fish.

“Isotopic analysis of the small amount of human remains we have from the Iron Age seems to bear out this idea that there was very little fish consumption. And certainly you very rarely see it in the Iron Age middens; the fish found in these are often few, small and indicative of shallow-water, inland fishing.

“To some extent, we’re seeing a similar grade of fish to this in the interior of the broch, little saithe or sillocks, but in much larger numbers than previously seen and they’re in quite early contexts— we think in the Middle Iron Age. If that’s the case, we might be partially busting a myth about this lack of use of fish or interaction with that part of the maritime resource.

“But, at the same time, it’s not entirely clear what’s going on. We had a layer present within the broch that was very, very rich in limpet shells, and interspersed with that we had lots of fish bone — but mostly heads and tails. It’s as if they’re actually processing them there and then, and then the actual body of the fish is going off somewhere else —perhaps for drying or smoking?

“Why, therefore, we don’t tend to have a very substantial isotopic signature in human remains from the Iron Age indicative of fish consumption is another question, but certainly it’s interesting, finally, to get some evidence that fishing was part of these people’s lives.

Sampling operations under way inside the broch.

Sampling operations under way inside the broch.

“The bones indicate shallow, inland fishing, using lines, or maybe just offshore from a boat — definitely not deep sea species that you’d associate with the viking fisheries a few centuries later.

“All this was happening quite late in terms of the sequence of the broch — the bulk of the structure was still standing but possibly unroofed.

“But the interesting thing is that the fish bone and limpets are associated with ceramics which, if anything, look like they’re from the earlier part of the Middle Iron Age — perhaps as early as 400BC-300BC. So really early.

“And, of course, because these are relatively high deposits inside the broch, it stands to reason  that the structure must be quite early as well.

“We had previously spotted scorch marks on the inner wall face, and that has always seemed quite nonsensical to us — why would you burn stuff at the foot of an interior wall, scorching and cracking up the inside of the wall face?

“To do that while you’re hoping to sustain the building as a useful entity seemed a bit ridiculous. The layer of shell and fish bone is stratigraphically associated with those burning episodes, and we’ve found three or four examples of these burning episodes. But from the way in which the scorching is licking up over the stonework, it looks as if the building wasn’t even entirely roofed at this stage. Maybe the evidence of burning points at the fact that they were smoking and drying fillets.

“We need independent dating evidence beyond the pottery to confirm when this activity was taking place, but if it is borne out, then it’s really interesting that they’re doing this at this period. Because in the Middle Iron Age you just do not see fish bone in any quantity. Admittedly, our site has tremendous bone preservation, so it may be that it was happening elsewhere but the evidence didn’t survive.”

A culinary sign of wealth and power . . .

Built into the broch site, adjacent to the building constructed above the souterrain was what appears to have been a Late Iron Age domestic building.

This structure has provided the archaeologists with a wealth of material that points at what can only be described as some serious Iron Age showing-off.

Martin explained: “The midden material from this building was just thrown outside, and contains incredibly rich food waste.

“In some Iron Age sites, you only get tiny splinters of bone, because they’re smashing up the bone to make sure they get everything possible from the joint, but here there’s evidence for an incredible amount of waste — lots of big joints of meat, with nothing like the kind of pulverizing you see on bones that have been fragmented to extract every bit of calorific value. This implies that these people were fairly well off.

“The waste, particularly the animal bone assemblage, is great for us because it means we’ve got really great, big chunks of animal bone that we can look at, and these can tell us an awful lot about the lifestyle of the animal — how they were managed, their health, their age at death, seasonality, that sort of thing.

“But what it is really telling us is that, for these people, the conspicuous non-consumption of food was maybe part and parcel of their status and identity – that waste, thrown out the front of the building, may have been evident to visitors and people who were here, perhaps signalling their wealth and, by association, power.”

Was this the home of a kept group of metalworkers who were working in the nearby “smithy”?

“They are certainly wealthy enough,” said Martin, “where they can afford to have specialists who are not having to contribute to the day-to-day agricultural work and the like. These are effectively people who have been brought out of the normal round of farming duties and are spending all their time producing ‘bling’, personal ornaments, utensils, weapons and tools.

“This year, the small amount of work we’ve carried out in the workshop area has revealed a completely unexpected number of fine bronze objects. We’ve had a little belt buckle, a copper stud, and lots of copper alloy fragments from a very small window of excavation on the workshop, so the evidence that there was metalworking in the later phases of the site continues to be unearthed, matching to what we’ve found in previous seasons.”

“But it’s possible that the domestic structure was a high-status communal building — maybe a building where there was lots of conspicuous feasting going on, and there was more than just the resident household engaged in those episodes of food consumption. That’s maybe why the midden is just so rich.

“As well as the domestic waste, we’ve found other examples of ‘bling’, including beautiful bone pins, bronze and iron objects, all reflecting objects worn on the body, attached to garments and intended to be seen by others.”

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