Heidelberg 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
UP: Fachverband Umweltphysik
UP 10: Ozeanographie
UP 10.6: Vortrag
Donnerstag, 26. März 2015, 18:30–18:45, G/gHS
Extraction of neodymium isotopes from different phases of deep sea sediments by selective leaching — •Patrick Blaser1, Jörg Lippold2, Norbert Frank1, Marcus Gutjahr3, and Evelyn Böhm1 — 1Ruprecht-Karls-Universität Heidelberg, Germany — 2Universität Bern, Switzerland — 3GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Germany
The analysis of seawater-derived neodymium (Nd) isotopes in marine sediments provides a unique proxy for deep water provenance, and thus ocean circulation, in particular in the Atlantic. Bottom water Nd is archived in different authigenic phases in the sediment. Extracting this Nd from mineral accretions bound to foraminiferal tests has lately become the preferred since most reliable method. Attempts have also been made to extract the Nd-rich authigenic fraction by leaching it off the bulk sediment and thereby use this proxy with less effort, in the highest possible resolution and in sediments where foraminifera are not sufficiently present. However, often other sedimentary components are also leached in the process and contaminate the extracted Nd. In this project several sediments across the Atlantic were leached in ten consecutive steps with two commonly used acidic solutions. The leachates were analysed on their elemental and Nd isotope compositions, as well as rare earth element (REE) distributions. By graduating the total leaching procedure into smaller stages the results display which processes take place in the course of sediment leaching in the laboratory and thus help to better evaluate the quality of sediment leaches for Nd isotope analysis.