A data brief on magnesium isotope compositions of marine calcareous sediments and ferromanganese nodules

作者：Rose Koga Estelle F^*; Albarede Francis

来源：Geochemistry Geophysics Geosystems, 2010, 11: Q03006.

DOI：10.1029/2009GC002899

• magnesium isotopes
• ferromanganese nodules
• carbonates
• calcareous sediments

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 delta(26)Mg (between -1.89 +/- 0.24 and -0.54 +/- 0.01%, 2s) scatter around the average ocean water value of -0.86 +/- 0.12%. Indian Ocean nodules display a large variation in delta(26)Mg ranging from -2.94 +/- 0.46 to + 0.69 +/- 0.18%. As for calcareous sediments, delta(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 delta(26)Mg mapping in Fe-Mn nodules and suggests that what controls the delta(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.

• 出版日期2010-3-11