Nonchondritic 142Nd in suboceanic mantle peridotites

Cipriani, Anna; Bonatti, Enrico; W. Carlson, Richard

The discovery that several solid Earth reservoirs have a superchondritic 142Nd/144Nd ratio led to the hypothesis that either the bulk silicate Earth is not chondritic or that a subchondritic reservoir lies hidden somewhere within the Earth's interior. One important reservoir, i.e., mid-ocean ridge peridotites representing the main component of the upper oceanic mantle and the source of mid-ocean ridge basalt, has never been tested for 142Nd/144Nd. We determined the 142Nd/144Nd ratio in clinopyroxene separated from two peridotites and a pyroxenite from the SW Indian Ridge and one peridotite from the northern Mid-Atlantic Ridge. All samples analyzed have superchondritic 142Nd/144Nd ratios in line with mantle-derived material measured to date, except for some ancient cratonic rocks.



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Geochemistry, Geophysics, Geosystems

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
Published Here
September 25, 2012