Hot on the heels of excavation at Easter Croftintygan and Ardnagaul last week, the Living on Water team has been back to Loch Tay to conduct the final underwater work for the project. Our goal this year was very specific. Since we have found that a lot of the crannogs in Loch Tay which had radiocarbon dates from 800–400 cal BC actually date the very end of this period, would it also be the case that crannogs which have radiocarbon dates from 400–200 cal BC actually mostly date from around 400–350 cal BC. Using wiggle-match dating techniques we can test this.

Weather was ideal for the work during the week.

Firbush crannog is one of two in Loch Tay to have rangefinder radiocarbon dates calibrating 400–200 cal BC (the other is Croftmartaig near Acharn). Firbush is located on the south side of the loch, near the University of Edinburgh’s Outdoor Activity Centre (thanks for all their help and support!). It was last investigated in 1979, when the radiocarbon sample was taken and the site was surveyed.

Preservation of the alder timbers was very good. This is at least 2000 year old wood!
The timbers are exposed at the base of the crannog mound, and needed only a light clean before recording and sampling.

Our work over three days relocated exposed timbers on the loch bed around the crannog which were noted in the 1979 survey. We sampled 15 of these alder timbers. This group of timbers is very remarkable for their tidiness. What this means is somewhat unclear, but it might suggest these timbers are all part of a very coherent, probably contemporary, phase of building activity. Dendrochronological analysis should These timbers are near where the 1979 sample was taken, so hopefully we should be able to address our question. Is there even more activity around 400 cal BC? We should find out soon.