Autre(s) titre(s) |
On the origin of phosphates from the nauru atoll |
Type |
Article |
Date |
1991 |
Langue(s) |
Français |
Auteur(s) |
Bernat M, Loubet M, Baumer A |
Source |
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1991 , Vol. 14 , N. 4 , P. 325-331 |
WOS© Times Cited |
4 |
Keyword(s) |
PHOSPHATES, ATOLLS, ISOTOPES, U, TH, SR |
Résumé en anglais |
Phosphates from the Nauru atoll lie on a karstic structure developed at the expenses of a coral reef. These formations are fluorapatites low in carbonate, with less fluorine than common marine carbonate-fluorapatites (CFA). At least one of the deposits is from the last interglacial era (Th-230-U-234 dating). Rare Earth spectra seems to be affected by the dissolution-precipitation reactions leading to the formation of the carbonate-fluorapatite. But U and Sr isotopic ratios support the marine origin of most of these formations, except for one result, which give a Nd-143/Nd-144 ratio indicating a slight volcanic influence. Our results and the literature reports favorise the hypothesis that these phosphates originate from the endo-upwelling of phosphorus rich deep seawater through the fracturated and porous mass of the carbonated reef. |
Texte intégral |
Fichier |
Pages |
Taille |
Accès |
18974.pdf |
7 |
497 KB |
Libre accès |
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