Open AccessA data brief on magnesium isotope compositions of marine calcareous sediments and ferromanganese nodules
Author(s) -
RoseKoga Estelle F.,
Albarède Francis
Publication year - 2010
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2009gc002899
Subject(s) - calcareous , ferromanganese , geology , diagenesis , oceanography , sediment , paleoceanography , bioturbation , phosphorite , geochemistry , mineralogy , phosphate , manganese , chemistry , paleontology , organic chemistry
The magnesium isotope compositions of 26 ferromanganese nodules from various oceans and 22 calcareous sediment samples from Ocean Drilling Program (ODP) leg sites from the Atlantic (ODP704, leg 114) and the Pacific (ODP846, leg 138) have been analyzed by Multicollector–Inductively Coupled Plasma–Mass Spectrometer. Most nodules from the Pacific and Atlantic oceans have δ 26 Mg (between −1.89 ± 0.24 and −0.54 ± 0.01‰, 2 σ ) scatter around the average ocean water value of −0.86 ± 0.12‰. Indian Ocean nodules display a large variation in δ 26 Mg ranging from −2.94 ± 0.46 to +0.69 ± 0.18‰. As for calcareous sediments, δ 26 Mg variations range between −2.94 ± 0.50 and −0.71 ± 0.45‰ and between −4.00 ± 0.31 and −1.63 ± 0.09‰ for the Atlantic and the Pacific legs, respectively. This study allows the construction of a thread of global δ 26 Mg mapping in Fe‐Mn nodules and suggests that what controls the δ 26 Mg variations of marine calcareous sediments is complex and probably linked both to a mixture of different tests of micro‐organisms and to diagenesis.