Application of ³⁴S analysis for elucidating terrestrial, marine and freshwater ecosystems: evidence of animal movement/husbandry practices in an early Viking community around Lake Mývatn, Iceland

Sayle, K. L. , Cook, G. T. , Ascough, P. L. , Hastie, H. , Einarsson, Á., McGovern, T. H., Hicks, M. T., Edwald, Á. and Friðriksson, A. (2013) Application of ³⁴S analysis for elucidating terrestrial, marine and freshwater ecosystems: evidence of animal movement/husbandry practices in an early Viking community around Lake Mývatn, Iceland. Geochimica et Cosmochimica Acta, 120(1), pp. 531-544. (doi: 10.1016/j.gca.2013.07.008)

Abstract

Carbon and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) have been used widely in archaeology to investigate palaeodiet. Sulphur stable isotope ratios (δ³⁴S) have shown great promise in this regard but the potential of this technique within archaeological science has yet to be fully explored. Here we report δ³⁴S, δ¹³C and δ¹⁵N values for 129 samples of animal bone collagen from Skútustaðir, an early Viking age (landnám) settlement in north-east Iceland. This dataset represents the most comprehensive study to date of its kind on archaeological material and the results show a clear offset in δ³⁴S values between animals deriving their dietary resources from terrestrial (mean = +5.6 ± 2.8‰), freshwater (mean = −2.7 ± 1.4‰) or marine (mean = +15.9 ± 1.5‰) reservoirs (with the three food groups being significantly different at 2σ). This offset allows reconstruction of the dietary history of domesticated herbivores and demonstrates differences in husbandry practices and animal movement/trade, which would be otherwise impossible using only δ¹³C and δ¹⁵N values. For example, several terrestrial herbivores displayed enriched bone collagen δ³⁴S values compared to the geology of the Lake Mývatn region, indicating they may have been affected by sea-spray whilst being pastured closer to the coast, before being traded inland. Additionally, the combination of heavy δ¹⁵N values coupled with light δ³⁴S values within pig bone collagen suggests that these omnivores were consuming freshwater fish as a significant portion of their diet. Arctic foxes were also found to be consuming large quantities of freshwater resources and radiocarbon dating of both the pigs and foxes confirmed previous studies showing that a large freshwater radiocarbon (¹⁴C) reservoir effect exists within the lake. Overall, these stable isotope and ¹⁴C data have important implications for obtaining a fuller reconstruction of the diets of the early Viking settlers in Iceland, and may allow a clearer identification of the marine and/or freshwater ¹⁴C reservoir effects that are known to exist in human bone collagen.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cook, Professor Gordon and Sayle, Dr Kerry and Kinch, Ms Helen and Ascough, Dr Philippa
• Authors: Sayle, K. L., Cook, G. T., Ascough, P. L., Hastie, H., Einarsson, Á., McGovern, T. H., Hicks, M. T., Edwald, Á., and Friðriksson, A.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Geochimica et Cosmochimica Acta
• Publisher: Elsevier
• ISSN: 0016-7037
• ISSN (Online): 1872-9533
• Copyright Holders: Copyright © 2013 Elsevier
• First Published: First Published in Geochimica et Cosmochimica Acta 120(1):531-534
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher