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Correlation of Marine 14C Ages from the Nordic Seas with the GISP2 Isotope Record: Implications for 14C Calibration Beyond 25 ka BP

Published online by Cambridge University Press:  18 July 2016

Antje H. L. Voelker ,
Michael Sarnthein ,
Pieter M. Grootes ,
Helmut Erlenkeuser ,
Carlo Laj ,
Alain Mazaud ,
Marie-Josée Nadeau  and
Markus Schleicher
Antje H. L. Voelker
Affiliation:
Geologisch-Paläontologisches Institut, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Michael Sarnthein
Affiliation:
Geologisch-Paläontologisches Institut, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Pieter M. Grootes
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Helmut Erlenkeuser
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Carlo Laj
Affiliation:
Centre des Faibles Radioactivités, Laboratoire mixte CEA-CNRS, Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
Alain Mazaud
Affiliation:
Centre des Faibles Radioactivités, Laboratoire mixte CEA-CNRS, Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
Marie-Josée Nadeau
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Markus Schleicher
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
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Abstract

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We present two new high-resolution sediment records from the southwestern Iceland and Norwegian Seas that were dated by numerous 14C ages up to 54 14C ka bp. Based on various lines of evidence, the local 14C reservoir effect was restricted to 400–1600 yr. The planktic stable isotope records reveal several meltwater spikes that were sampled with an average time resolution of 50 yr in PS2644 and 130 yr in core 23071 during isotope stage 3. Most of the δ18O spikes correlate peak-by-peak to the stadials and cold rebounds of the Dansgaard-Oeschger cycles in the annual-layer counted GISP2 ice core, with the major spikes reflecting the Heinrich events 1–6. This correlation indicates large fluctuations in the calibration of 14C ages between 20 and 54 14C ka bp. Generally the results confirm the 14C age shifts as predicted by the geomagnetic model of Laj, Mazaud and Duplessy (1996). However, the amplitude and speed of the abrupt decrease and subsequent major increase of our 14C shifts after 45 14C ka bp clearly exceed the geomagnetic prediction near 40–43 and 32–34 calendar (cal) ka bp. At these times, the geomagnetic field intensity minima linked to the Laschamp and the Mono Lake excursions and confirmed by a local geomagnetic record, probably led to a sudden increase in cosmogenic 14C and 10Be production, giving rise to excess 14C in the atmosphere of up to 1200%.

Type
Part 1: Methods
Information
Radiocarbon , Volume 40 , Issue 1: 16th International Radiocarbon Conference 16-20,1997 Groningen , 1997 , pp. 517 - 534
Copyright
Copyright © The American Journal of Science 

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