Blogpost by Leonore Kitt (Excavations Assistant)
During the excavations back in 2024, you have probably seen me and a few helping hands jamming a metal cylinder on the walls of the kailyard and the rig and furrow test pits. Once in the lab, those samples proved very useful to have a better insight into how the inhabitants of Achnacon used the land for agricultural purposes. Meike Maria Van Lit, a PhD candidate at the University of Glasgow, and I looked at different characteristics of the soil, such as its bulk density, which uses the dry soil’s volume and weight to determine its compaction. With this method, we found that the soil in the rig and furrow is more compacted, which might show it was more intensively managed than the kailyard.
Another characteristic that we looked at was soil organic matter (SOM). We measure this by firing the soil in an oven at 550°C for 2h and weighing what is left. The deeper the context, the lower the SOM: irregularities then give information on if the land was managed at a specific time, for example through ploughing or manuring. We found soil from the rig and furrow had a higher SOM than the kailyard, which is proof again of more intense land management there. We also used the oven to measure the calcium carbonate content (CaCO3) in the soil by firing the subsamples a second time at 950°C for 4h. We found that the contexts with the highest CaCO3 content were hard pans.
Finally, we looked at the soil’s pH, by mixing the soil in water and calcium chloride and measuring its pH using a pH-meter. We found that the soil from the rig and furrow had a higher (less acidic) pH than the soil from the kailyard.
The subsamples are ready for pH measurement.
Getting familiar with the lab environment and procedures has been an interesting experience: I find there is usually this question of ‘what next?’ when it comes to excavations – this experience has given me an insight into what happens after they are finished and more importantly, the answers it gives to questions that we can’t answer on site. One of the things I like most about archaeology is how interdisciplinary it is, and you can see here how earth sciences and geology, amongst many other fields, are integral to the process of archaeological interpretation.
Keep your eyes peeled for future updates from our finds specialists and labs in the coming months!
You can check out previous post-ex blog posts here:
Leave a Reply