Rare Earth Elements in the surface Ocean under the Saharan dust belt

Michiel.Rutgers.v.d.Loeff [ at ] awi.de


The supply of trace metals to the surface ocean via dust deposition is important for primary productivity and the global biogeochemical cycle of many elements. Here we utilise the systematic variation of the chemical properties of yttrium and the rare earth elements (YREE) to investigate trace metal release from dust in the equatorial Atlantic Ocean. We present YREE data for the dissolved (<0.45 μm) and suspended particulate matter (SPM) collected from the mixed layer during Polarstern cruise ANT-XXIII/1 in Oct-Nov 2005. Saharan dust can be traced with the Al content of the SPM revealing a broad maximum extending from 15° to 3°N. The PAAS normalised YREE patterns of the dust dominated SPM are relatively flat with a broad peak centred around Eu and Gd. This dust dominated SPM is also characterised by lower Y/Ho and Er/Nd ratios than the particulate material from outside the high Al zone. The dissolved YREE distributions show normal seawater patterns with the relative enrichment of heavy REE over light REE. The samples with dust dominated SPM are enriched in the light and middle REE by a factor of approximately 2 compared to the other samples and a Sargasso Sea surface water. The dissolved Y/Ho and Er/Nd ratios obtained from the dust dominated SPM zone are also low compared to the samples outside the zone but display a fractionation between the SPM and the dissolved phase. This comparison indicates a consistent incongruent dissolution of the dust associated YREE which are probably mainly hosted by oxide coatings on the particles.

Item Type
Article (Conference paper)
Primary Division
Primary Topic
Peer revision
Not peer-reviewed
Publication Status
Event Details
Goldschmidt Conference, 25 Aug 2013 - 30 Aug 2013, Florence.
Eprint ID
DOI 10.1180/minmag.2013.077.5.8

Cite as
Hathorne, E. C. , Frank, M. , Rutgers v. d. Loeff, M. , Roeske, T. and Rickli, J. (2013): Rare Earth Elements in the surface Ocean under the Saharan dust belt , Mineralogical Magazine: Goldschmidt Conference Abstracts, 77 (5), p. 1271 . doi: 10.1180/minmag.2013.077.5.8



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