000K  utf8
1100  $c2007
1500  eng
2050  urn:nbn:de:gbv:8-diss-19627
3000  Regenberg, Marcus
4000  Inorganic and stable isotope geochemistry of tropical Atlantic/Caribbean planktonic foraminifera : implications for the reconstruction of upper ocean temperatures and stratification$hChristian-Albrechts-Universität zu Kiel  [Regenberg, Marcus]
4030  Kiel$nChristian-Albrechts-Universität zu Kiel
4209  Planktonic foraminifera from tropical Atlantic and Caribbean sediment-surface samples (0-1 cm) show general westward-directed increasing calcification depths depending on the east-west increase in thermocline depth. Positively related planktonic foraminiferal Mg/Ca and carbonate ion concentration in the Caribbean show well preserved Mg/Ca down to depths about 1.5 km above the lysocline, which equals a carbonate ion concentration of 26-18 µmol/kg. Species-specific calibrations of Mg/Ca with d18O-derived calcification temperatures reveal similar exponential and differing preexponential constants for shallow- and thermocline-dwelling compared to deep-dwelling species. For multispecies, a "warm water" and a "cold water" calibration was derived. Alteration of deep-sea sediments in the vicinity of the Bahama platform results in micro-scale inorganic crystallites on planktonic foraminiferal tests, which synchronize the absence of high Mg-calcite from the sediments. Mg/Ca and Sr/Ca of the crystallites are 4-6 times elevated and 2-3 times depleted, respectively, compared to the original foraminiferal test.
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-19627$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/diss_mods_00001962
5051  550
5550  Atlantischer Ozean
5550  calcification depth
5550  carbonate ion concentration
5550  diagenesis
5550  dissolution
5550  Foraminiferen
5550  Isotopengeochemie
5550  laser ablation
5550  Mg/Ca ratios
5550  oxygen isotope values
5550  planktonic foraminifera
5550  stratification
5550  temperature calibration