1 JOINED-UP ARCHAEOLOGY AT OLD SCATNESS, SHETLAND: THIN SECTION ANALYSIS OF THE SITE AND HINTERLAND E.B.A. Guttmann 1 , I.A. Simpson 1 and S.J. Dockrill 2 ( 1 Department of Environmental Science, University of Stirling, Stirling FK9 4LA; 2 Department of Archaeological Sciences, University of Bradford, West Yorkshire BD7 1DP) Abstract Excavations on the multi-period settlement at Old Scatness, Shetland have uncovered a number of Iron Age structures with compacted, floor-like layers. Thin section analysis was undertaken in order to investigate and compare the characteristics of these layers. The investigation also draws on earlier analyses of the Iron Age agricultural soil around the settlement and the midden deposits which accumulated within the settlement, to create a ‘joined-up’ analysis which considers the way in which material from the settlement was used and then recycled as fertiliser for the fields. Peat was collected from the nearby uplands and was used for fuel and possibly also for flooring. It is suggested that organic- rich floors from the structures were periodically removed and the material was spread onto the fields as fertilisers. More organic-rich material may have been used selectively for fertiliser, while the less organic peat ash was allowed to accumulate in middens. Several of the structures may have functioned as byres, which suggests a prehistoric plaggen system. KEYWORDS: IRON AGE, AGRICULTURE, PLAGGEN SOILS, SHETLAND, MICROMORPHOLOGY, FLOORS Introduction Identifying the function of prehistoric structures can be problematic. Structures with hearths are generally interpreted as dwellings (Fowler 1983) and structures with pits through the floor are often thought to be for storage (Reynolds 1974; Bradley et al. 1980) although many structures have both. Pairs of circular post-built structures are commonly interpreted as having distinct, complimentary functions, with one structure acting as a domestic dwelling and the ancillary structure used for other activities such as cooking and/or storage (Ellison 1980). This pattern has also been noted in Orkney and Caithness, where most Iron Age roundhouses have ancillary storage structures such as souterrains or earth-houses (Foster 1989).