The Plants and the People from Buiston Crannog, Ayrshire, Scotland

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The 'crannog' of Buiston

The word 'crannog' is a term used in Scotland and Ireland to describe a category of archaeological structures forming partially or wholly man-made islands in lakes, rivers and estuaries (e.g. Morrison 1985). They are often interpreted as dwellings or strongholds, but, as Crone (1988) points out, these are not universally applicable. With the exception of one example from South Wales, crannogs are concentrated in Scotland and Ireland. Recent survey work on the Scottish sites (Barber & Crone 1993) and a series of new radiocarbon dates (Crone 1993; in press) indicate that their construction in Scotland spans at least 2000 years. In southwestern Scotland three main periods of construction are apparent; in the 1st millennium BC, between the 4th and 7th centuries AD and in the medieval period.

Buiston is one of the many crannogs in southwestern Scotland [ILLUSTRATION FOR FIGURE 1 OMITTED]. Because the surrounding land was drained in the 19th century, it lies today in a shallow basin in rolling agricultural land; it is submerged below standing water only during the wetter months of the winter. As part of the initial attempts at drainage, some 13 cart-loads of timber were reported to have been removed from the site, indicating something of the scale of the original structure. The first archaeological excavations at the site were undertaken by Munro, a local antiquarian, in 1880 and 1881 (Munro 1882), when he unearthed a considerable palisaded settlement with middens rich in artefacts. In 1989 it was included in a survey of the crannogs of southwest Scotland (Barber & Crone 1993), and was later selected for more detailed investigation regarding the condition of surviving timbers. In spite of land drainage, preservation of organic remains by waterlogging was exceptionally good, marking Buiston as a wetland site of international importance. The large volume of well-preserved botanical remains presented considerable scope for detailed analysis of the local environment. Much was inevitably characteristic of a water-loving lake-edge flora. The natural deposition of large quantities of such material interspersed with flooring and roofing deposits is certain to have masked less abundant economic indicators. Nevertheless, some of the more abundant elements, in conjunction with the other organic components, such as the worked wood and leather recovered from the same deposits, have been used to reconstruct aspects of life on the crannog with considerable precision.

The initial mound: construction, abandonment and environmental context

The initial crannog mound, some 11.6 m in diameter, comprises a series of regularly alternating layers of clearly defined clay turves and thick layers of wood-litter piled on to the loch bed over a foundation layer of oak beams and large boulders (Crone forthcoming). A basal layer of brushwood produced a radiocarbon date of 1950[+ or -]50 b.p. (GU-3000) while the uppermost one gave a comparable date of 1920[+ or -]50 b.p. (GU-3391), placing this phase into the later Iron Age for this part of Britain. Although there was a total absence of in situ occupation deposits or anthropogenic debris from these early layers, the turf, brushwood and lake sediments used in construction offered good environmental evidence. Pollen and the macroscopic remains of higher plants and mosses from the turf indicated that these were cut from areas of open or lightly wooded vegetation. The brushwood itself included hazel (Corylus avellana), willow (Salix sp,) and birch (Betula sp.) which would be compatible with this and also with heather (Calluna vulgaris), indicating the presence of open acid heath in the vicinity.

Sediments deriving from the lake itself could be identified by their aquatic component. These offered somewhat contradictory signals with respect to the nutrient status of the lake; the majority suggested a pH close to neutral with water depth between 0. …