The influence of geology and pedology is the key concept in summarizing the geophysics report I have now received from Dr Andreas Viberg. The fact is that our measurements with the ground penetrating radar at the site of Sa 14.9 (fieldwork that I have described here) are most distinctly informative about the border between the area of moraine and the lower-lying areas with clay soils… Indeed, the site is mainly located in a stone-rich moraine terrain and this, apparently, made it very problematic to determine which of the anomalies captured by the GPR represent archaeological and which of geological features underground. This, obviously, does not mean that there is no archaeology left in the original context in the stone-rich moraine terrain, it just means that GPR data does not allow us to uniformly interpret all the anomalies observed underground. Despite that reality, there were still a number of anthropogenic features positively identified in the investigated areas.
To start with, we could clearly see the traces of modern plowing as well as field ditches possibly from the early modern era – which is hardly interesting. But east from the hall, another longhouse, which was already recognized during the geophysical fieldwork just by visual observances, the same longhouse was clear in the GPR data as well – 20 m long, but only about 5 m wide. Together with the observations made in the field (the building was perceived thanks to the 15 x 4 m sandy patch in the soil interpreted as a floor-layer and surrounded with lumps of wattle-and-daub) and the fact that no clear post-holes were documented in the geophysics’ data, Andreas is explicit in his report that it is the cultivation of the land that has had a very negative impact to the preservation of recognizable structures. The impact of the cultivation is also mentioned in connection to the fact that from the hall itself, only its southern wall is visible in the GPR data. However, I am certain that through more detailed examination more features both inside the hall and outside will be documented.
It is how it is. The excavations will be next 🙂 Not only to validate as well as to find out what kind of anomalies that GPR has captured, but to find out if there are undisturbed contexts under the plow layer, to find out how much and what kind of find material there is at the site, and to take samples to get better dates – all in order to clarify the exact function of the site.