1) Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA, 2) Geological and Environmental Sciences, Stanford University, 450 Serra Mall, CA 94305, USA
Earth and Planetary Science Letters (2013), V365, pp63–76, doi: 10.1016/j.epsl.2013.01.0111
Abyssal peridotites reveal the near-chondritic Fe isotopic composition of the Earth
Paul R. Craddock (1), Jessica M. Warren (2), Nicolas Dauphas (1)
Terrestrial oceanic and continental basalts are enriched by approximately þ0.1% in 56Fe/54Fe ratio relative to primitive, undifferentiated meteorites (chondrites). The d56Fe values of terrestrial basalts are also distinct from those of basalts from Mars and asteroid Vesta, which have chondritic Fe isotopic compositions. The processes responsible for the isotopic enrichment of terrestrial basalts are debated, in part because the Fe isotopic composition of the mantle source of terrestrial basalts is unknown. Here we report Fe isotopic measurements of abyssal peridotites, which are the residues of limited melting at oceanic ridges and are thus the best proxies for the composition of the convective portion of the mantle.
- Fe isotopes