The Cairns Day Eighteen – 2018

Excavating in the western zone of the broch today
Excavating in the western zone of the broch in the gathering mist

The digging season at The Cairns is nearly over and Martin Carruthers, Site Director and Lecturer at the University of the Highlands and Islands Archaeology Institute, talks us through the penultimate day at the excavation.

Today we started the process of placing the covers over parts of the site. We began in the Area Q/M in the North of the site weighing down tarpaulins with tyres. Nevertheless, we remain in an active digging mode in other parts of the site.

Inside the broch the team have resumed excavating the western area on a sample grid. They are now working on floor/occupation deposits beneath the level of the two successive hearths that have been excavated and lifted. Tomorrow will be the last day when excavation occurs here, so will they find lots of lovely environmental information? And will they encounter any nice artefacts to rival the previous finds such as the Iron Age glass bead and the Roman vessel glass in this area? We’ll let you know…

The slightly wetter conditions overnight (in fact it was misty early on today!) have served to very nicely show the soil colours on the site so in the south extension we have been cleaning this area for final photography. Low and behold more animal bone has been appearing in this area, which has previously been so rich in it. Once the excavation is complete for the season, it will be interesting to take a look at all the animal bone that has been generated by the work in the ditch to try to get some idea of the nature of the processes that this bone has been involved in.

One of many trays of animal bone from site
One of the many trays of animal bone from site

Certainly, we have observed butchery marks on some of the bone but by and large the bone is present in large fragments with minimal processing and it therefore looks rather wasteful in terms of the additional calorific content that has not been exacted from these joints of meat. This has often been read off as an index of relative wealth, as poorer communities are expected to be less wasteful. However, we have also observed large parts of articulated carcasses amongst the animal bone suggesting that there may be other processes at work giving rise to at least some of this bone such as structured, or votive, deposition. The post-excavation work of looking in detail at all this bone will be very interesting, indeed.

Tomorrow will be the last day when any excavation occurs anywhere on site, and most of the site will be covered up by the end of the day, we’ll keep you posted on any last minute surprises (almost guaranteed on archaeological sites!).

Martin Carruthers, Site Director and Programme Leader for MSc Archaeological Practice at UHI Archaeology Institute

 

The Cairns Day Sixteen – 2018

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Looking across the broch with the Pentland Firth in the background

Dr Jo McKenzie has kindly volunteered to write the blog today………….Hello from the beginning of the end – the last week of the Cairns 2018 field season! (and sadly, my last day on site).

Time seems to have gone very quickly, and it doesn’t seem a year since I was last at Cairns sampling the amazing sequence of floor deposits preserved within, especially, the north-eastern quadrant of the broch.

You’ll have seen some of the images of these floors in several of Martin’s posts – beautiful, intricate lenses of material, each tiny layer representing a different episode of activity and deposition by those who were the last before us to spend their days ‘doing stuff’ in the Cairns broch.

I use a technique called soil micromorphology to take small ‘block’ samples which are then used to make microscope slides, allowing us to analyse complex deposit sequences like the broch floors in enormous detail – as outlined in my blog from last year (LINK). Here’s a shot of one of those samples being taken. This tin is just 5×7 cm, but that’s plenty big enough to give us a fantastic sample through the many deposits in this small section through lenses of probable charcoal, burnt peat, burnt stone, bone and much more.

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A micromorphology ‘Kubiena tin’ through the floor deposits of the north-east quadrant.

We now have a great sequence of samples through these complex deposits, traversing the north-east quadrant and nicely aligned within our 50cm grid (affectionately known as Terence for no good reason, except I suppose that it helps to be able to make a personal apology when you’ve kicked yet another of Terence’s nails out for the umpteenth time that day – as fellow north-east quadrant-ers Ole, Ross and Mike can testify!)

We’ve also been lucky enough to get enough depth of deposit to take a sample close to the large hearth setting in the north-west area of the broch, which is really good news as the closely-packed layers of paving in this area make getting good samples a challenge. Here’s today’s sample extracted, and turned carefully over for the excess material to be carefully shaved off the back of the tin so that the sample can be sealed. A lovely sample of dark, dense carbonised material representing activity around the cracked hearth surface.

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Extracting a sample from the north-west quadrant hearth

It’s intriguing to spot tiny features within the tin samples which I know will be so interesting to examine in detail under the microscope – fine laminations of material, or inclusions such as charcoal or bone. Here’s an example of what must be pretty much the tiniest bones we find on site – a fish vertebrae, seen adjacent to the tin taken next to the north-west hearth setting, seen here magnified under my small geological viewer.

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A tiny fish vertebra

It’s also been great to see the site making such amazing progress – so many new structures being uncovered outside of the broch with Bobby’s team, and spending these last few days working right alongside the fantastic discoveries still being made inside the well. Above all, it’s been brilliant to get the chance once again to work with the great Cairns team – students, volunteers and old hands alike. I think today must have been the busiest I’ve ever seen the broch interior – and needless to say, there was plenty of archaeology for every pair of hands to tackle!

Roll on next year.