Burnt plant remains
Analysed by Susan Ramsay and Jennifer Miller (GUARD)
Burnt peat or turf made up over 80% of the carbonized macroplant assemblage. Woodland was very scarce on Unst and driftwood was an unreliable source, so people would have had to use any other combustible material they could find. Much of the landscape of Unst would have consisted of rough grassland and blanket mire, and heather would have grown in both habitats. Peat was, and still is, commonly used in the Highlands and Islands of Scotland as fuel, particularly in areas where woodland has been cleared and blanket peat has formed in its place. Archaeological evidence for the use of peat as fuel on Shetland has been found at Jarlshof and the Biggins on Papa Stour. Abundant burnt grass and heather stems, heather flowers, leafy shoots and crowberry seeds suggest that grassland or heathland turves were also being burned at Sandwick. Above-ground heather stems may have been collected initially for flooring, roofing or bedding but then later used as fuel. Seeds from grassland habitats were also found – including sedges, heath grass, knotweeds, redshank and buttercups – suggesting that turves were taken from a variety of habitats.
Most of the wood charcoal came from spruce or fir. As neither is native to Scotland, it probably arrived on Unst as driftwood – either from Scandinavia or the eastern seaboard of North America. Oak charcoal from the excavations might have also come from driftwood, or from wooden artefacts brought from the mainland. Willow and perhaps hazel charcoal were also found, and these might have been growing on Unst in the Iron Age.
Burnt cereal grains were found in many deposits – mostly six-row barley, along with a little hulled barley and a single grain of wheat. Chaff was only found in one deposit. From the amounts of grain and chaff found, it appears that the inhabitants were storing and perhaps processing grain at the settlement, but not in great quantities.