Trays of the ‘black stuff’
Today was a bit of a day for charcoal finds!
A strange thing to say, perhaps, but then, strangely enough, across the site interesting (and somewhat remarkable) discoveries of “the black stuff” simultaneously emerged that give important insights into the environment at The Cairns.
Inside the broch, UHI Associate Professor Scott Timpany, our resident archaeobotanist, began to investigate one edge of the north-east room, where it leads into the chamber in the wall (the north-east cell), and here he found a mass of charcoal and clay.
Meanwhile, I’m investigating the fragment of a first-floor gallery present on the wall-top near the broch entrance. Again, a mass of charcoal and clay have emerged. Indeed, the way the clay and charcoal fragments are suffused here suggests the possibility of wattle and daub, a wicker-like frame with clay smeared on it. It’s possible there was an upright panel of hurdle and daub here in the gallery and that it was pushed down and maybe set on fire when the broch was abandoned.
The third occurrence of noteworthy charcoal today represented the most spectacular preservation, and it came from over in Structure B2, our wag-typem sub-rectangular building dating from around AD300.
As Jan worked around the central hearth to better define it, she lifted a relatively small stone from the floor and revealed a mass of astonishingly well preserved and very, very delicate heather twigs and very fine florets adhering to the underside of the stone while many more remain in the ground. You can see from the image just how fine and fragile these are, so their survival is well-nigh miraculous!
Now, lest we’re tempted to think these are just oddities of preservation and vaguely evocative of the plant life of the past, we should actually consider the kind of information that we can obtain from charcoal.
Once upon a time, charcoal in archaeology was largely a source of radiocarbon dating with a bit of attention to cereal grains but these days with the right kind of expertise, such as that offered by the aforementioned Scott, we can consider how woodland resources like that implicated in the possible wattle screen were managed, how people pruned the branches, and stored the wood, which we can get at by looking at radial cracks in roundwood structure and tiny insect tunnels preserved in charcoal that show wood had a chance to dry and season prior to being used.
We can look at the types of wood used across the site for fuel (domestic and metalworking), and for building and we can assess how the community was organising itself to manage this woodland (perhaps especially in a place like Orkney where woodland resources were very likely relatively scarce and precious during the Iron Age.
During our post-excavation work to come in future years, we will find out a lot more about these issues as we work through all the material collected during the field work…
Elsewhere on site today, before the rain interrupted things this afternoon, work progressed well in the broch with “the cut” for the well emerging nicely in the north room, allowing us to recover details of its construction.
Meanwhile, in the south-east room, Amanda, Angus, Karen, and Elspeth continued to excavate the vivid yellow clays of the earthen floor. We think this will also soon reveal the full extent of the enigmatic stone-filled feature of the room.
In the west room more details of the stone-lined ash box, next to the hearth, were revealed, an important feature of how people were using this important major source of heat, light, and cooking.
On the outside the broch, it was a quite a finds-rich day. In the paved zone of the courtyard space, where Craig is working, very nice large pieces of Iron Age pottery with intact rim were found. Craig also found a pivot stone, where, 2,000 years ago, a door post would have swung, perhaps part of the arrangements of the approach toward the broch entrance along this paved space.
Hopefully, tomorrow will bring some equally illuminating findings and progress…
Martin Carruthers
Site director
