Icelandic volcanic ash from the Late-glacial open-air archaeological site of Ahrenshoft LA 58 D, North Germany

摘要

Cryptotephra of Icelandic origin from the open-air archaeological site of Ahrensh?ft LA 58 D(Kr. Nordfriesland, Schleswig-Holstein), northern Germany overlies a Late-glacial Havelte lithic assemblage,hitherto dated by ~(14)C and biostratigraphy to the earliest part of the Late-glacial interstadial (GI-1eto GI-1c_3). Peaks in ash shards are observed in two profiles. Major and minor element geochemistryindicates volcanic ash originating in the Katla system. Precise correlation to previously described tephrais uncertain due to overlapping chemical characteristics. The Ahrenshft ~(14)C determinations, litho- andbio-stratigraphy encompass a broad age-span for the cryptotephra bearing sediments, from the end ofthe Aller?d to the Preboreal. The most plausible volcanic eruption correlates are the Vedde Ash(wYounger Dryas), already known from the European mainland, tephra AF555 (late Younger Dryas) andthe Suduroy tephra (wPreboreal/Boreal), hitherto recorded only in the North Atlantic region. These threeash horizons have been dated to, respectively, 12,171 57 yr b2k in the NGRIP ice-core, c.11,500 cal BP, inScotland and c.8000 cal BP, by radiocarbon from the Faroe Isles. Ongoing research on deposits from thetype sites for the tephra layers may in the future differentiate these markers leading to betterdiscrimination of the chemistries and a resolution of this question.