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| Titel |
A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany |
| VerfasserIn |
Sebastian F. M. Breitenbach, Birgit Plessen, Sarah Wenz, Jens Leonhardt, Rik Tjallingii, Denis Scholz, Klaus Peter Jochum, Norbert Marwan |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133586
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| Publikation (Nr.) |
 EGU/EGU2016-14213.pdf |
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| Zusammenfassung |
| Although Holocene climate dynamics were relatively stable compared to glacial conditions,
climatic changes had significant impact on ecosystems and human society on various
timescales (Mayewski et al. 2004, Donges et al. 2015, Tan et al. 2015). Precious few
high-resolution records on Holocene temperature and precipitation conditions in
Central Europe are available (e.g., von Grafenstein et al. 1999, Fohlmeister et al.
2012).
Here we present a speleothem-based reconstruction of past climate dynamics from Blessberg
Cave, Thuringia, central Germany. Three calcitic stalagmites were recovered when the cave
was discovered during tunneling operations in 2008. Samples BB-1, -2 and -3 were precisely
dated by the 230Th/U-method, with errors between 10 and 160 years (2σ). The combined
record covers large parts of the Holocene (10 – 0.4 ka BP). δ13C and δ18O were analysed at
100 μm resolution. To gain additional insights in infiltration conditions, Sr/Ca and S/Ca
were measured on BB-1 and BB-3 using an Röntgenanalytik Eagle XXL μXRF
scanner.
Differences to other central European records (e.g., von Grafenstein et al. 1999, Fohlmeister
et al. 2012) suggest complex interaction between multiple factors influencing speleothem
δ18O in Blessberg Cave. Furthermore, no clear influence of the North Atlantic Oscillation on
our proxies is found. However, a link across the N Atlantic realm is indicated by a
centennial-scale correlation between Blessberg δ18O values and minerogenic input into lake
SS1220 in Greenland over the last 5 ka (Olsen et al. 2012). In addition, recurrence analysis
indicates an imprint of Atlantic Bond events on Blessberg δ18O values (Marwan et
al. 2014), corroborating the suggested link with high northern latitudes. Larger
runoff into the Greenland lake seems to be associated with lower δ18O, higher
δ13C and S/Ca ratios, as well as lower Sr/Ca ratios in Blessberg Cave speleothems.
This might be linked to lower local temperature and/or changes in precipitation
seasonality. Opposing millennial scale trends with lowering S/Ca ratios and δ13C values
but increasing Sr/Ca ratios calls for more than one controlling factor. Most likely,
δ13C decreased through the Holocene due to afforestation, which in turn might
have increased sulphate retention in the thickening soil cover (Frisia et al. 2005)
and limited sulphur flux into the cave. Alternatively, marine sulfur flux could have
diminished with winter wind intensities. However, additional data is required to clarify
this hypothesis. A positive Sr/Ca trend through the Holocene might result from
increasing prior calcite precipitation induced by a negative moisture balance in
summer.
References
Breitenbach et al. (2012) Climate of the Past 8, 1765-1779
Donges et al. (2015) Climate of the Past 11, 709-741
Fohlmeister et al. (2012) Climate of the Past 8, 1751-1764
Frisia et al. (2005) EPSL 235, 729-740
Marwan et al. (2014) Geophysical Research Abstracts 16, EGU2014-8893
Mayewski et al. (2004) Quaternary Research 62, 243-255
Olsen et al. (2012) Nature Geoscience 5, 808-812
Tan et al. (2015) Scientific Reports 5:12284
von Grafenstein et al. (1999) Science 284, 1654-1657 |
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