This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wastegård, S. Articles by Hermanns-Auoardóttir, M. Search for Related Content GeoRef GeoRef Citation Social Bookmarking                   What's this?

Rhyolitic tephra horizons in northwestern Europe and Iceland from the AD 700s–800s: a potential alternative for dating first human impact

Department of Physical Geography and Quaternary Geology, Stockholm University, S-106 91 Stockholm, Sweden; stefan.wastegard{at}geo.su.se

Valerie A. Hall

Palaeoecology Centre and Institute of Irish Studies, Queen's University, Belfast BT7 1NN, Northern Ireland, UK

Gina E. Hannon

Southern Swedish Forest Research Centre, SLU, S-230 53 Alnarp, Sweden

Christel van den Bogaard

GEOMAR, Research Center for Marine Geosciences, Wischhofstrasse 1–3, D-24148 Kiel, Germany

Jonathan R. Pilcher

Palaeoecology Centre and Institute of Irish Studies, Queen's University, Belfast BT7 1NN, Northern Ireland, UK

Magnús Á. Sigurgeirsson

Icelandic Radiation Protection Institute, RauDarárstíg 10, IS-150 Reykjavík, Iceland

Margrét Hermanns-Auoardóttir

The Reykjavík Academy, Hringbraut 121, IS-107 Reykjaviík, Iceland

The distribution and geochemistry of four rhyolitic tephra horizons from Iceland dated to the ad 700s–800s is assessed. These include the rhyolitic phase of the Landnám tephra (ad 870s), the ad 860 layer, a previously unrecorded tephra called the GA4–85 layer (c. ad 700–800) and the Tjïrnuvík tephra (c. ad 800s). The ad 860 and GA4–85 layers were first found in peat bogs in north Ireland. They are here correlated with equivalent horizons on Iceland which were found below the Landnám tephra (c. ad 870s). This time period is considered important in the North Atlantic region, because it coincides with a phase of human settlement in Iceland and the Faroe Islands. The establishment of a detailed tephrochronology may provide a tool for exact dating of sediment successions and sediments associated with archaeological excavations. Caution must be taken especially on Iceland where the Landnám tephra is often used for dating archaeological sites. This investigation show that several rhyolitic tephra horizons occur close in time to the Landnám tephra, and that mistakes can be made if detailed geochemical analyses are not carried out, especially in areas which are distal to the source of the Landnám tephra (the Veidivötn and Torfajökull volcanic systems, southern Iceland).

Key Words: Iceland • Ireland • Faroe Islands • Germany • tephra • Landnám • human impact

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. Barber, P. Langdon, and A. Blundell Dating the Glen Garry tephra: a widespread late-Holocene marker horizon in the peatlands of northern Britain The Holocene, January 1, 2008; 18(1): 31 - 43. [Abstract] [PDF]

				G. B. Kristjansdottir, J. S. Stoner, A. E. Jennings, J. T. Andrews, and K. Gronvold Geochemistry of Holocene cryptotephras from the North Iceland Shelf (MD99-2269): intercalibration with radiocarbon and palaeomagnetic chronostratigraphies The Holocene, February 1, 2007; 17(2): 155 - 176. [Abstract] [PDF]

				W. R. Gehrels, W. A. Marshall, M. J. Gehrels, G. Larsen, J. R. Kirby, J. Eiriksson, J. Heinemeier, and T. Shimmield Rapid sea-level rise in the North Atlantic Ocean since the first half of the nineteenth century The Holocene, November 1, 2006; 16(7): 949 - 965. [Abstract] [PDF]

				M. J. Gehrels, D. J. Lowe, Z. J. Hazell, and R. M. Newnham A continuous 5300-yr Holocene cryptotephrostratigraphic record from northern New Zealand and implications for tephrochronology and volcanic hazard assessment The Holocene, February 1, 2006; 16(2): 173 - 187. [Abstract] [PDF]

				V. A. Hall, V. A. Hall, and D. Mauquoy Tephra-dated climate-and human-impact studies during the last 1500 years from a raised bog in central Ireland The Holocene, November 1, 2005; 15(7): 1086 - 1093. [Abstract] [PDF]

				G. M. Plunkett, J. R. Pilcher, F. G. McCormac, and V. A. Hall New dates for first millennium BC tephra isochrones in Ireland The Holocene, July 1, 2004; 14(5): 780 - 786. [Abstract] [PDF]