The past and present trace metal budget of the Black Sea - A comparison of the Holocene and Eemian marine ingression
Zusammenfassung der Projektergebnisse
In our project we have created a huge data set for the so far unexplored Eemian Black Sea sapropel, which comprises analyses of 55 elements, four isotopic systems, and organic biomarkers. The interpretation of this data set results in the following major findings: • It was possible to create a lithological unit classification for the Eemian sapropel analogous to the Holocene. • Fe/Al ratios and δ56Fe values in combination with isorenieratane and δ13C may be used to depict the development oft he chemocline in a stratified anoxic basin over time. • The Black Sea chemocline oscillated at least twice during the Holocene, while it rose continuously in the Eemian. • Ubiquitous trace metal patterns in the Holocene sapropel indicate that changes in the water column chemistry affect the whole Black Sea basin on very short time scales; our composite geochemical core log (CGCL) has been proven as a powerful chemostratigraphic tool. • The δ97Mo and δ238U values show a shift to isotopically lighter compositions in the Eemian compared with the Holocene, but they also indicates a similar successive change from oxic to euxinic conditions. • The lower sapropels at station 22 were deposited during MIS 5e, with an average sedimentation rate of ~4.0 cm/kyr (almost half of the Holocene sedimentation rate at the same station). • Mo inventory calculations show lower inflow rates for Mediterranean seawater during the Eemian interglacial compared to the Holocene at station 22. • Element enrichments of the DSDP samples are comparable to the samples of the Eemian sapropels of station 22, indicating ubiquitary biogeochemical processes during the preceding interglacial.
Projektbezogene Publikationen (Auswahl)
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(2009). Trace metal patterns in Black Sea sapropels as a chemostratigraphic tool. European Geoscience Union General Assembly 2009. Vienna, Austria
S. Eckert, B. Schnetger, H.-J. Brumsack
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(2009). Trace metal patterns in Black Sea sapropels as a chemostratigraphic tool. lODP/lCDP Kolloquium, Potsdam, Germany
S. Eckert, B. Schnetger, H.-J. Brumsack
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(2010). Geochemical comparison of the Eemian and Holocene interglacial marine ingression into the Black Sea. European Geosciences Union General Assembly 2010. Vienna. Austria
S. Eckert, B. Schnetger, C. Montoya-Pino, S. Weyer, H. Arz, H.-J. Brumsack
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(2010). The Eemian sapropel - geochemical signatures and paleoenvironmental interpretation of the penultimate interglaciai in the Black Sea. lODP/ICDP Kolloquium, Frankfurt a.M., Germany
S. Eckert, B. Schnetger, C. Montoya-Pino, S. Weyer, H. Arz, H.-J. Brumsack
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(2011). Chemocline oscillations in the Black Sea documented by sedimentary iron isotopes and trace metal patterns. Goldschmidt 2011. Prague. Czech Republic
S. Eckert, B. Schnetger, H. Fröllje, S. Severmann, C. Montoya-Pino, S. Weyer, J. Köster, H. Arz, H.-J. Brumsack
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(2011). Paleoenvironmental reconstruction of the Black Sea basin during the Eemian interglacial by means of geochemical and isotopic studies. lODP/ICDP Kolloquium. Münster. Germany
S. Eckert, B. Schnetger, C. Montoya-Pino, S. Weyer, J. Köster, S. Severmann, H. Arz, H.-J. Brumsack
