High-precision radiocarbon dating of the construction phase of Oakbank Crannog, Loch Tay, Perthshire

Cook, G. , Dixon, T.N., Russell, N., Naysmith, P. , Xu, S. and Andrian, B. (2010) High-precision radiocarbon dating of the construction phase of Oakbank Crannog, Loch Tay, Perthshire. Radiocarbon, 52(2), pp. 346-355.

Abstract

Many of the Loch Tay crannogs were built in the Early Iron Age and so calibration of the radiocarbon ages produces very broad calendar age ranges due to the well-documented Hallstatt plateau in the calibration curve. However, the large oak timbers that were used in the construction of some of the crannogs potentially provide a means of improving the precision of the dating through subdividing them into decadal or subdecadal increments, dating them to high precision and wiggle-matching the resulting data to the master ¹⁴C calibration curve. We obtained a sample from 1 oak timber from Oakbank Crannog comprising 70 rings (Sample OB06 WMS 1, T103) including sapwood that was complete to the bark edge. The timber is situated on the northeast edge of the main living area of the crannog and as a large and strong oak pile would have been a useful support in more than 1 phase of occupation and may be related to the earliest construction phase of the site. This was sectioned into 5-yr increments and dated to a precision of approximately ±8–16 ¹⁴C yr (1 σ). The wiggle-match predicts that the last ring dated was formed around 500 BC (maximum range of 520–465 BC) and should be taken as indicative of the likely time of construction of Oakbank Crannog. This is a considerable improvement on the estimates based on single ¹⁴C ages made on oak samples, which typically encompassed the period from around 800–400 BC.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Naysmith, Mr Phillip and Cook, Professor Gordon and Xu, Dr Sheng and Russell, Dr Nicola
• Authors: Cook, G., Dixon, T.N., Russell, N., Naysmith, P., Xu, S., and Andrian, B.
• Subjects: C Auxiliary Sciences of History > CC Archaeology; G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Radiocarbon
• Publisher: University of Arizona
• ISSN: 0033-8222
• Published Online: 01 January 2010
• Copyright Holders: Copyright © 2010 Arizona Board of Regents on behalf of the University of Arizona
• First Published: First published in Radiocarbon 52(2):346-355
• Publisher Policy: Reproduced with the permission of the publisher / editor