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| Thomson, J; Crudeli, D; De Lange, Gj; Slomp, Cp; Erba, E; Corselli, C; Calvert, Se. |
| High relative concentrations of the lower photic zone nannofossil Florisphaera profunda have been reported in all recent eastern Mediterranean sapropels. In the most recent sapropel (S1), high bulk sediment Sr/Ca ratios occur along with high F. profunda contents toward the base of the unit, exemplified here in four cores from 1.5-3.5 km water depth. Co-occurring biogenic carbonates contain insufficient Sr to account for these high Sr concentrations, and X-ray diffraction and selective leaching show that the high Sr/Ca ratios are due to aragonite, the CaCO3 polymorph that is rarely preserved in deep marine sediments, with similar to1 wt % Sr. The possible sources of this aragonite include ( 1) precipitation with surface ocean production, ( 2) detrital input... |
| Tipo: Text |
Palavras-chave: Sapropel; Aragonite; Strontium. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/33975/32412.pdf |
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