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Radiocarbon Dating Tephra Layers in Britain and Iceland

Published online by Cambridge University Press:  18 July 2016

A. J. Dugmore ,
G. T. Cook ,
J. S. Shore ,
A. J. Newton ,
K. J. Edwards  and
GuÐrún Larsen
A. J. Dugmore
Affiliation:
Department of Geography, University of Edinburgh, Edinburgh, EH8 9XP, Scotland
G. T. Cook
Affiliation:
Scottish Universities Research and Reactor Centre, Scottish Enterprise Technology Park, East Kilbride, G75 0QF, Scotland
J. S. Shore
Affiliation:
Scottish Universities Research and Reactor Centre, Scottish Enterprise Technology Park, East Kilbride, G75 0QF, Scotland
A. J. Newton
Affiliation:
Department of Geography, University of Edinburgh, Edinburgh, EH8 9XP, Scotland
K. J. Edwards
Affiliation:
Department of Archaeology and Pre-History, University of Sheffield, Sheffield, S10 2TN, England
GuÐrún Larsen
Affiliation:
Science Institute, University of Iceland, Reykjavik, IS-101 Iceland
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Abstract

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Layers of volcanic ash, or tephra form widespread chronostratigraphic marker horizons which are important because of their distinctive characteristics and rapid deposition over large areas. Absolute dating of prehistoric layers effectively depends upon 14C analysis. We focus here on Icelandic tephra layers at both proximal and distal sites and consider three strategies to obtain age estimates: 1) the conventional dating of individual profiles; 2) high-precision multisample techniques or “wiggle-matching” using stratigraphic sequences of peat; and 3) a combination of routine analyses from multiple sites. The first approach is illustrated by the dating of a peat profile in Scotland containing tephra from the ad 1510 eruption of Hekla. This produced a 14C age compatible with ad 1510, independently derived by geochemical correlation with historically dated Icelandic deposits. In addition, the ca. 2100 bp date for the Glen Garry tephra in Scotland, determined by a series of dates on a peat profile in Caithness, is supported by its stratigraphic position within 14C dated profiles in Sutherland, and may be applied over a very large area of Scotland. More precise dates for individual tephras may be produced by “wiggle-matching”, although this approach could be biased by changes in peat-bog stratigraphy close to the position of the tephra fall. As appropriate sites for “wiggle-match” exercises may be found only for a few Icelandic tephras, we also consider the results of a spatial approach to 14C dating tephra layers. We combined dates on peat underlying the same layer at several sites to estimate the age of the tephra: 3826 ± 12 bp for the Hekla-4 tephra and 2879 ± 34 bp for the Hekla-3 tephra. This approach is effective in terms of cost, the need for widespread applicability to Icelandic tephra stratigraphy and the production of ages of a useful resolution. We stress the need for accurate identification of tephra deposits without which the conclusions drawn from subsequent 14C dating will be fundamentally flawed.

Type
III. Calibration of the 14C Time Scale
Information
Radiocarbon , Volume 37 , Issue 2 , 1995 , pp. 379 - 388
Copyright
Copyright © the Department of Geosciences, The University of Arizona 

References

Baillie, M. L. 1989a Do Irish bog oaks date the Shang Dynasty? Current Archaeology 117: 301–310.Google Scholar
Baillie, M. L. 1989b Hekla 3- just how big was it? Endeavour 13(2): 78–81.Google Scholar
Baillie, M. L. and Munro, M.A.R. 1988 Irish tree rings; Santorini and volcanic dust veils. Nature 332: 344–346.CrossRefGoogle Scholar
Barber, K. E. 1981 Peat Stratigraphy and Climatic Change , Balkema, Rotterdam.Google Scholar
Bennett, K. D., Boreham, S., Sharp, M.J. and Switsur, V. R. 1992 Holocene history of environment, vegetation and human settlement on Catta Ness, Lunnasting, Shetland. Journal of Ecology 80: 241–273.Google Scholar
Björk, S., Ingólfsson, O., Hafliôason, H., Hallsdóttir, M. and Anderson, N. J. 1992 Lake Torfadalsvatn: A high resolution record of the North Atlantic ash zone I and the last glacial-interglacial environmental changes in Iceland. Boreas 21: 15–22.CrossRefGoogle Scholar
Blackford, J. J., Edwards, K. J., Dugmore, A. J., Cook, G. T. and Buckland, P. C. 1992 Icelandic volcanic ash and the mid-Holocene Scots pine (Pinus sylvestris) pollen decline in northern Scotland. The Holocene 2: 260–265.CrossRefGoogle Scholar
Buckland, P. C., Dugmore, A. J. and Edwards, K. J. (ms.) Volcanic activity and human response in the Mediterranean and the North Atlantic region. Quaternary Science Reviews , in press.Google Scholar
Burgess, C. 1989 Volcanoes, catastrophe and global crisis of the late 2nd millennium BC. Current Archaeology 117: 325–329.Google Scholar
Dugmore, A. J. 1987 (ms.) Holocene Glacial Fluctuations Around Eyjafjallajökull, South Iceland. Ph.D. dissertation, University of Aberdeen: 214 p.Google Scholar
Dugmore, A. J. 1989 Tephrochronological studies of Holocene glacier fluctuations in southern Iceland. In Oerlemans, J., ed., Glacier Fluctuations and Glacial Change , Dordrecht, Kluwer Academic Publishers: 37–55.Google Scholar
Dugmore, A. J., Larsen, G., and Newton, A. J. 1995 Seven tephra isochrones in Scotland. The Holocene 5(3): 257–266.CrossRefGoogle Scholar
Dugmore, A. J., Larsen, G., Newton, A. J. and Sugden, D. E. 1992 Geochemical stability of fine-grained silicic tephra layers in Iceland and Scotland. Journal of Quaternary Science 7: 173–183.Google Scholar
Dugmore, A. J. and Newton, A. J. 1992 Thin tephra layers in peat revealed by X-radiography. Journal of Archaeological Science 19: 163–170.Google Scholar
Edwards, K. J., Buckland, P. C., Blackford, J. J., Dugmore, A. J. and Sadler, J. P. 1994 The impact of tephra: Proximal and distal studies of Icelandic eruptions. Muncher Geographische Auhandlungen B12: 79–101.Google Scholar
Hall, V. A., Pilcher, J. R. and McCormac, F. G. 1994 Icelandic volcanic ash and the mid-Holocene Scots pine (Pinus sylvestris) decline in the north of Ireland: No correlation. The Holocene 41: 79–83.Google Scholar
Hallsdóttir, M. 1987 Pollen analytical studies of human influence on vegetation in relation to the. Landnám tephra layer in southwestern Iceland. Lundqua Thesis 18: 1–45.Google Scholar
Hunt, J. and Hill, P.G. 1993 Tephra geochemistry: a discussion of some persistent analytical problems. The Holocene 3: 271–278.CrossRefGoogle Scholar
Imsland, P. 1978 Petrology of Iceland; some general remarks. Nordic Volcanological Institute Reports 7808: 1–19.Google Scholar
Jakobsson, S. P. 1979 Petrology of recent basalts of the Eastern Volcanic Zone, Iceland. Acta Naturalia Islandica 26: 1–103.Google Scholar
Kjartansson, G., Thórarinsson, S. and Einarsson, Th. 1964 14C dating of Quaternary deposits in Iceland. Nátturufraedingurinn 34: 97–145.Google Scholar
Larsen, G. 1981 Tephrochronology by microprobe glass analysis. In Self, S. and Sparks, R. S. J., eds., Tephra Studies , Dordrecht, Reidel: 95–102.CrossRefGoogle Scholar
Larsen, G. 1982 Gjóskutímatal Jökuldals og nágrennis (Tephrochronology of Jokuldalur and the surrounding areas). In Thorarindóttir, H., Öskarsson, Ó. H., Steinthórsson, S. and Einarsson, Th., eds., Eldur er í Norôri. Sógufelag, Reykjavik: 51–66.Google Scholar
Larsen, G. 1984 Recent volcanic history of the Veiôivötn fissure swarm, southern Iceland – An approach to volcanic risk assessment. Journal of Volcanology and Geothermal Research 22: 33–58.Google Scholar
Larsen, G., Newton, A. J. and Dugmore, A. J. The Suinafell tephra reference profile in southeast Iceland. Unpublished manuscript.Google Scholar
Larsen, G. and Thórarinsson, S. 1977 H4 and other acidic Hekla tephra layers. Jökull 27: 28–46.CrossRefGoogle Scholar
Merkt, J., Muller, H., Knabe, W., Muller, P. and Weiser, T. 1993 The early Holocene Saksunarvatn Tephra found in lake sediments in N.W. Germany. Boreas 22: 93–100.CrossRefGoogle Scholar
Ogilvie, A. E. J. 1984 The past climate and sea-ice record from Iceland, Part 1: Data to AD 1780. Climate Change 6: 131–152.Google Scholar
Pearson, G.W. and Stuiver, M. 1993 High-precision bidecadal calibration of the radiocarbon time scale 500–2500 bc. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 25–33.Google Scholar
Pilcher, J. R., and Hall, V. A. 1992 Towards a tephrochronology for the Holocene of the north of Ireland. The Holocene 2: 255–259.Google Scholar
Pilcher, J. R., Hall, V. A. and McCormac, F. G. 1994 Dating tephra layers in peats by high precision multi-sample technique. (Abstract) 15th International Radiocarbon Conference, Glasgow, Scotland, 15–19 August.Google Scholar
Pilcher, J. R., Hall, V. A. and McCormac, F. G. 1995 Dates of Holocene eruptions from tephra layers in Irish peats. The Holocene 5: 103–110.Google Scholar
Shore, J. S., Cook, G. T. and Dugmore, A. J. 1995 The 14C content of modern vegetation samples from the flanks of the Katla volcano, southern Iceland. Radiocarbon , this issue.Google Scholar
Stuiver, M. and Reimer, P. J. 1993 Extended 14C data base and revised CALIB 3.0 14C age calibration program. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 215–230.Google Scholar
Thórarinsson, S. 1967 The eruption of Hekla in historical times. The eruption of Hekla 1947–1948 1: 1–170.Google Scholar
Thórarinsson, S. 1981 Greetings from Iceland – Ash-falls and volcanic aerosols in Scandinavia. Geografiska Annaler Series A 633–4: 109–110.CrossRefGoogle Scholar
Vogel, J. S., Cornell, W., Nelson, D. E. and Southon, J. R. 1990 Vesuvius/Avellino, one possible source of seventeenth century BC climatic disturbances. Nature 344: 534–537.Google Scholar