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| Titel |
The bivalve Glycymeris planicostalis as a high-resolution paleoclimate archive for the Rupelian (Early Oligocene) of central Europe |
| VerfasserIn |
E. O. Walliser, B. R. Schöne, T. Tütken, J. Zirkel, K. I. Grimm, J. Pross |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 4 ; Nr. 11, no. 4 (2015-04-10), S.653-668 |
| Datensatznummer |
250117258
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| Publikation (Nr.) |
 copernicus.org/cp-11-653-2015.pdf |
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| Zusammenfassung |
| Current global warming is likely to result in a unipolar glaciated world
with unpredictable repercussions on atmospheric and oceanic circulation
patterns. These changes are expected to affect seasonal extremes and the
year-to-year variability of seasonality. To better constrain the mode and
tempo of the anticipated changes, climatologists require
ultra-high-resolution proxy data of time intervals in the past, e.g., the
Oligocene, during which boundary conditions were similar to those predicted
for the near future. In the present paper, we assess whether such information can
be obtained from shells of the long-lived bivalve mollusk Glycymeris planicostalis from the late
Rupelian of the Mainz Basin, Germany. Our results indicate that the studied
shells are pristinely preserved and provide an excellent archive for
reconstructing changes of sea surface temperature on seasonal to interannual
timescales. Shells of G. planicostalis grew uninterruptedly during winter and summer and
therefore recorded the full seasonal temperature amplitude that prevailed in
the Mainz Basin ~ 30 Ma. Absolute sea surface temperature
data were reconstructed from δ18Oshell values assuming a
δ18Owater signature that was extrapolated
from coeval sirenian tooth enamel. Reconstructed values range between
12.3 and 22.0 °C and agree well with previous
estimates based on planktonic foraminifera and shark teeth. However,
temperatures during seasonal extremes vary greatly on interannual timescales. Mathematically re-sampled (i.e., corrected for uneven number of
samples per annual increment) winter and summer temperatures averaged over
40 annual increments of three specimens equal 13.6 ± 0.8
and 17.3 ± 1.2 °C, respectively. Such high-resolution
paleoclimate information can be highly relevant for numerical climate
studies aiming to predict possible future climates in a unipolar glaciated
or, ultimately, polar-ice-free world. |
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