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| Titel |
Temperature reconstructions on carbonate mounds (IODP Site 1317) using elemental ratios (Mg/Ca, Mg/Li, Sr/Ca) as well as non-traditional isotope techniques |
| VerfasserIn |
Jacek Raddatz, Volker Liebetrau, Anton Eisenhauer, Andres Rüggeberg, Ed Hathorne, Dirk Nürnberg, Wolf-Christian Dullo  |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056104
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| Zusammenfassung |
| In paleoceanographic terms cold-water coral mounds have the unique property to provide
geochemical and climate information of the past from two different archives (cold-water
corals and foraminifera). This study shows a direct comparison of well developed
paleo-temperature proxies on benthic foraminifera P. ariminensis (δ18O-Mg/Ca) as well as
potential temperature proxies in the scleractinian cold-water coral L. pertusa from
Challenger Mound (IODP Site 1317) initiated at ~ 2.6 Ma (Kano et al., 2007). Potential
paleo-temperature proxies (Sr/Ca, Mg/Li and δ88-86Sr ratios) were all calibrated on
live-in situ sampled L. Pertusa along the European continental margin. For δ88-86Sr
determinations we used the new developed Doubel-Spike-TIMS technique and found
a negative δ88-86Sr relationship to tempretaure (6-10Ë C), signficantly different
to that have been published earlier (Fietzke and Eisenhauer 2006; Rüggeberg et
al., 2008). Coral Sr/Ca ratios show the excpected negative linear relationship and
Mg/Li ratios show a positive linear relationship. Our results show that downcore
Sr/CaLopheliaratios give unrealistic low values. Whereas downcore Mg/LiLophelia and
δ88-86SrLophelia ratios result in reasonable temperature values in the order of ~6Ë C
and ~12Ë C for the mound record investigated. In support of this foraminiferal
Mg/Caariminensis temperatures show values from about 9.5Ë C to 12.5Ë C for the upper
mound interval.
Our reconstructed paleo-temperatures from cold water coral L. pertusa are interpreted as
a warming of intermediate water masses since the onset of the Challenger mound formation.
We suggest that this trend reflect vertical movements of the Mediterranean Outflow Water
(MOW) generating mound waxing and wanning. |
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