Die Quantifizierung des marinen Sr-Haushaltes mittels radiogener (87Sr/86Sr) und stabiler (delta 86/88Sr) Sr-lsotopenverhältnisse
Final Report Abstract
Within this study the first Phanerozoic stable strontium (Sr) isotope seawater record (δ88/86Srsw) is reconstructed, which is sensitive to imbalances in the Sr input and output fluxes. In a consequent model approach, the radiogenic Sr isotope record (87Sr/86Sr)sw and δ88/86Srsw are used to constrain the marine Phanerozoic Sr budget. On long timescales (~200Myr periodicity), δ88/86Srsw and modelled Sr carbonate burial rates (F(Sr)carb) follow times of proposed „aragonite seas“ and „calcite seas“, implying that the dominant carbonate mineralogy has an important effect on Sr burial rates. On shorter timescales, minima and maxima in F(Sr)carb are partly correlated to ocean anoxia and glaciations and related sea-level low stands, implying the importance of continental carbonate shelf weathering to the marine Sr budget. In particular, enduring high carbonate burial rates for ~21Myr could be related to seawater anoxia during the end-Permian mass extinctions. Ultimately, insights from changes in δ88/86Srsw significantly improved our understanding of long-term changes in seawater chemistry and the relation of carbonate-related Sr fluxes to sea-level changes, mass extinctions, and global anoxia.
Publications
- (2013). Stable Sr-isotope, Sr/Ca, Mg/Ca, Li/Ca and Mg/Li ratios in the scleractinian cold-water coral Lophelia pertusa. Chem. Geol. 352, 143-152
Raddatz, J., Liebetrau, V., Rüggeberg, A., Hathorne, E., Krabbenhöft, A., Eisenhauer, A., Böhm, F., Vollstaedt, H., Fietzke, J., López Correa, M., Freiwald, A., Dullo, W.C.
(See online at https://doi.org/10.1016/j.chemgeo.2013.06.013) - (2009) Determination of radiogenic and stable strontium isotope ratios (87Sr/86Sr; 588/86Sr) by thermal ionization mass spectrometry applying an 87Sr/84Sr double spike Journal of Analytical Atomic Spectrometry, 24 (9). pp. 1267-1271
Krabbenhöft, A., Fietzke, J., Eisenhauer, A., Liebetrau, V., Böhm, F. and Vollstaedt, H.
(See online at https://doi.org/10.1039/B906292K) - (2010) Constraining the marine strontium budget with natural strontium isotope fractionations (87Sr/86Sr*, ö88/86Sr) of carbonates, hydrothermal solutions and river waters Geochimica et Cosmochimica Acta, 74 (14). pp. 4097-4109
Krabbenhöft, A., Eisenhauer, A., Böhm, F., Vollstaedt, H., Fietzke, J., Liebetrau, V., Augustin, N., Peucker-Ehrenbrink, B., Müller, M., Horn, C., Hansen, B. T., Nolte, N. and Wallmann, K.
(See online at https://dx.doi.org/10.1016/j.gca.2010.04.009) - 2013. The Phanerozoic delta Sr-88/86 record of seawater: New constraints on past changes in oceanic carbonate fluxes. Geochimica et Cosmochimica Acta 128, 249-265
Vollstaedt, H., Eisenhauer, A., Wallmann, K., Boehm, F., Fietzke, J., Liebetrau, V., Krabbenhoeft, A., Farkas, J., Tomasovych, A., Raddatz, J., and Veizer, J.
(See online at https://doi.org/10.1016/j.gca.2013.10.006)
