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| Titel |
87Sr/86Sr as a quantitative geochemical proxy for 14C reservoir age in dynamic, brackish waters: assessing applicability and quantifying uncertainties. |
| VerfasserIn |
Bryan Lougheed, Jeroen van der Lubbe, Gareth Davies |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250122080
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| Publikation (Nr.) |
 EGU/EGU2016-1017.pdf |
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| Zusammenfassung |
| Accurate geochronologies are crucial for reconstructing the sensitivity of brackish
and estuarine environments to rapidly changing past external impacts. A common
geochronological method used for such studies is radiocarbon (14C) dating, but its application
in brackish environments is severely limited by an inability to quantify spatiotemporal
variations in 14C reservoir age, or R(t), due to dynamic interplay between river runoff and
marine water. Additionally, old carbon effects and species-specific behavioural processes also
influence 14C ages. Using the world’s largest brackish water body (the estuarine
Baltic Sea) as a test-bed, combined with a comprehensive approach that objectively
excludes both old carbon and species-specific effects, we demonstrate that it is
possible to use 87Sr/86Sr ratios to quantify R(t) in ubiquitous mollusc shell material,
leading to almost one order of magnitude increase in Baltic Sea 14C geochronological
precision over the current state-of-the-art. We propose that this novel proxy method
can be developed for other brackish water bodies worldwide, thereby improving
geochronological control in these climate sensitive, near-coastal environments. |
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