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| Titel |
A multi-centennial time series of well-constrained ΔR values for the Irish Sea derived using absolutely-dated shell samples from the mollusc Arctica islandica |
| VerfasserIn |
P. G. Butler, J. D. Scourse, C. A. Richardson, A. D. Wanamaker Jr |
| 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 |
250021038
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| Zusammenfassung |
| Determinations of the local correction (ΔR) to the globally averaged marine radiocarbon
reservoir age are often isolated in space and time, derived from heterogeneous sources and
constrained by significant uncertainties. Although time series of ΔR at single sites can be
obtained from sediment cores, these are subject to multiple uncertainties related to
sedimentation rates, bioturbation and interspecific variations in the source of radiocarbon in
the analysed samples. Coral records provide better resolution, but these are available only for
tropical locations. It is shown here that it is possible to use the shell of the long-lived bivalve
mollusc Arctica islandica as a source of high resolution time series of absolutely-dated
marine radiocarbon determinations for the shelf seas surrounding the North Atlantic ocean.
Annual growth increments in the shell can be crossdated and chronologies can be
constructed in a precise analogue with the use of tree-rings. Because the calendar
dates of the samples are known, ΔR can be determined with high precision and
accuracy and because all the samples are from the same species, the time series
of ΔR values possesses a high degree of internal consistency. Presented here is a
multi-centennial (AD 1593 – AD 1933) time series of 31 ΔR values for a site in the Irish Sea
close to the Isle of Man. The mean value of ΔR (-62 14C yrs) does not change
significantly during this period but increased variability is apparent before AD 1750. |
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