Open AccessAbundance of zinc isotopes as a marine biogeochemical tracer
Author(s) -
Maréchal Chloé N.,
Nicolas Emmanuel,
Douchet Chantal,
Albarède Francis
Publication year - 2000
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/1999gc000029
Subject(s) - ferromanganese , upwelling , geology , sediment , biogeochemical cycle , seawater , oceanography , isotope , scavenging , sediment trap , water column , productivity , tracer , environmental chemistry , mineralogy , manganese , chemistry , geomorphology , physics , organic chemistry , quantum mechanics , nuclear physics , biochemistry , economics , macroeconomics , antioxidant
The Zn isotopic compositions of ferromanganese nodules, sediment trap samples, sediments, and organic reference samples have been analyzed by multiple collector inductively coupled plasma–mass spectrometry (ICP‐MS). The range of isotopic variations (1‰ for 66 Zn/ 64 Zn) is significant with respect to the analytical precision (0.04‰ at the 95% confidence level). Marine argillaceous sediments show rather constant values consistent with those of continental shales and loess and with the value of a basalt from Réunion Island. We infer that the depletion of the light Zn isotopes in marine particles and in ferromanganese nodules (presumably equilibrated with seawater) results from biological activity in the upper water column. The δ 66 Zn values of sediment trap samples collected near the upwelling off the coast of Mauritania (central Atlantic) show a seasonal isotopic fluctuation consistent with biological pumping during the high‐productivity period. Higher values of δ 66 Zn in nodules appear to be associated with the amplitude of seasonal variations rather than with the mean values of the biological productivity.