Radiocarbon results from an archaeological site excavated this summer Threave Estate outside Castle Douglas have confirmed it dates from the Iron Age period.
Archaeologists from the conservation charity spent a week excavating on the site of an enclosure on Little Wood Hill, overlooking Threave Castle, with the help of a group of ten volunteers participating in a Trust Thistle Camp working holiday.
The site was known from aerial photography taken in the 1940s and 1980s and appeared in plan as a D-shaped ditch enclosing an area about 30m across. Ploughing on the site over the years has flattened almost all traces of any internal bank. Four trenches were excavated: three over the enclosing ditch on the north, east and west sides and a small trench in the interior.
Where fully excavated, the ditch was found to be at least two metres wide and up to 1.2 metres deep and was almost V-shaped in profile. Despite digging the topsoil off and emptying the ditch fill by hand the number of artefacts recovered was pretty low. A range of modern material from the topsoil included pottery and glass shards, although some iron slag and a few flakes of flint could be prehistoric in date.
The fill of the ditch, however, contained quite large numbers of charcoal flecks and lumps and samples were obtained for dating purposes.
Derek Alexander, Head of Archaeological Services for the National Trust for Scotland, said: “It is always exciting to get radiocarbon results, especially when there was very little else that we could use to date the site. This is the first confirmed prehistoric date that we have on our large estate at Threave.
“Other sites are known close by, and the discovery, in the 19th century, of significant Iron Age metalwork in Carlingwark Loch and from Torrs, close to Castle Douglas, indicate that this was an area of major importance 2000 years ago.”
The carbon dating gave a date of 1968±30 BP (before 1950AD). This date falls immediately prior to the activities of the Roman army in the south-west during Agricola’s campaigns in the 80s AD.
The results were only recently returned by the lab at the Scottish Universities Environmental Research Centre.