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| Titel |
Validation of 30-50 14C ka ages from marine shells by amino acid D/L values |
| VerfasserIn |
J. Mangerud, D. Kaufman, J. I. Svendsen |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250022718
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| Zusammenfassung |
| Old 14C ages are always suspicious because samples with very low 14C content are sensitive
for contamination with recent or young 14C. We have obtained 32 radiocarbon ages in the
range 29-48 14C ka BP on marine shells from Novaya Zemlya, Arctic Russia, suggesting that
the Barents-Kara Ice Sheet was completely absent during much of Marine Isotope Stage 3
(Mangerud et al. 2008). This would be an important finding for paleo-glaciological and
paleo-climatological reconstructions and the reliability of the dates is therefore crucial.
Amino acid racemization is a chemical reaction that progresses independently of the
decay of 14C. We found a close correlation between 14C ages and D/L values from
aspartic and glutamic amino acids which strongly support the reliability of the 14C
ages.
Reference
Mangerud, J., Kaufman, D., Hansen, J. & Svendsen, J.I. (2008). Ice-free conditions
in Novaya Zemlya 35 000-30 000 years B.P., as indicated by radiocarbon ages
and amino acid racemisation evidence from marine molluscs. Polar Research 27,
187-208. |
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