Radiocarbon Dating of the Crannogs of Loch Tay, Perthshire (Scotland)

Abstract

ABSTRACT. Crannogs are ancient artificial islands found in Scotland and Ireland, which typically had some sort of dwelling place constructed on them that served variously as farmers' homesteads, status symbols, refuges in times of trouble, hunting and fishing stations, etc. Substantial research has been carried out for similar sites in mainland Europe, which has demonstrated that they were lakeside settlements, mostly dating to the Neolithic period and not built over open water. In contrast, the Scottish and Irish sites were built in open water, clearly separate from the shore. In Perthshire, some prehistoric crannogs were originally timber-built roundhouses supported on piles or stilts driven into the loch bed. Today, these crannogs appear as treecovered islands or remain hidden as submerged stony mounds. Until recently, there were few radiocarbon dates for these structures and so the sites appeared as a homogeneous group. Not only did this make it impossible to examine them in subgroupings but it also inhibited research, as they did not fit into known periods or architecturally distinct sub-groups, except that they were surrounded by water. Recent work in Loch Tay has resulted in ,4 C dating of the timber piles from 13 of the 18 crannogs in the loch, allowing them to be fitted into different classes. A major group was constructed in the Early Iron Age around 400-800 BC, with smaller groups constructed around 200-300 BC and 0 BC/AD. There is also evidence of repair/ reoccupation of some of these crannogs in the 6th-9th centuries AD. A number of the sites were also known to be inhabited into the recent past, with one, Priory Island, occupied until the 17th century. The dates of construction also raise important issues relating to the loch-level changes that have taken place. The ,4 C results will be discussed in relation to the periods of origin and habitation of the crannogs.

High-Precision Radiocarbon Dating of the Construction Phase of Oakbank Crannog, Loch Tay, Perthshire

“…This is a considerable improvement on the estimates based on 9 single 14 C ages previously made on oak samples, which typically encompassed the period from around 800-400 BC (Dixon et al 2007). While this study is based on a single oak timber, it demonstrates the potential for overcoming the broad calendar age ranges produced by dating single samples.…”

“…Most appear now as submerged or partially submerged piles of rocks or small, tree-covered, stony islands; however, beneath these rocks are often well-preserved timbers and numerous organic artifacts. In Loch Tay, there are the remains of 18 artificial island dwellings (Dixon 2004), and we have currently carried out radiocarbon dating on 13 of them (Dixon et al 2007). Within that group, it is possible to see divisions, with 9 sites ranging within the period 820-350 BC, 2 within the period 400-50 BC, and 2 from 170 BC-AD 180.…”

“…It has been subject to excavation for approximately the past 30 yr and evidence points to it being initially constructed as a free-standing pile dwelling with open water underneath the platform. All 9 14 C age measurements that have previously been made, including those on large structural timbers that were proposed to be associated with the initial construction phase, place its construction in the period 800-400 BC (Dixon et al 2007). It was decided because of the wealth of information that already existed about this site, including observations of large structural timbers, that it was the most suited to a first attempt at the wiggle-match approach.…”

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“…Iron Age studies on Loch Tayside and more generally within western Perthshire have tended to be limited, with the exception of Nick Dixon's work on the crannogs of the area Dixon et al 2007). This has led to a rather skewed distribution of known settlement-sites, in comparison to the denser distributions of house-types for this period in south-east and north-east Perthshire (RCAHMS 1990;.…”

“…During the Ben Lawers Project the strongest evidence for Iron Age occupation was identified through work on five crannogs, Morenish Crannog, Morenish Boathouse Crannog, Milton Morenish Crannog, Eilean Breaban and Tombreck Crannog (Dixon et al 2007). All had previously been surveyed, in 1979 and 2000 (Dixon 1982;Dixon 2004a).…”