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Rare earth elements and strontium isotopes of polymetallic nodules from southeastern Pacific Ocean
Author(s) -
COURTOIS CHANTAL,
CLAUER NORBERT
Publication year - 1980
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.1980.tb01655.x
Subject(s) - seawater , geology , strontium , rare earth element , rare earth , isotopes of strontium , nodule (geology) , geochemistry , archipelago , sediment , trace element , mineralogy , oil shale , pacific ocean , oceanography , geomorphology , paleontology , chemistry , organic chemistry
Rare earth element (REE) distributions and 87 Sr/ 86 Sr ratios were determined for nodule crusts and associated surface sediments collected in the southeastern Pacific Ocean between South America and the Tuamotu archipelago. The shale‐normalized patterns of the REE from the surface sediments show pronounced negative anomalies in Ce which indicate a marine origin. One 87 Sr/ 86 Sr ratio also has a value characteristic for seawater strontium. REE patterns from the nodule crusts, when normalized to shales, seawater or associated surface sediment, show that a marine origin can also be proposed for the oxy‐hydroxides. Only the Ce shows a systematic scatter, which could be the result of fluctuations in the oxidation‐reduction conditions during nodule growth. The marine origin for REE is corroborated by the 87 Sr/ 86 Sr ratios which average 0 · 70905 ± 0 · 00019 (2σ), a value close to the seawater 87 Sr/ 86 Sr ratio of 0·70910 ± 0 · 00035. If the major metals of the polymetallic nodules have the same origin as these trace elements, then a direct precipitation from seawater can be postulated for the crusts studied here.