Figure 2. Se isotope data for terrestrial and meteorite samples.

δ^82/76Se values of analysed peridotites (for simplicity all as circles) together with published data for terrestrial melts, including basalts from a variety of geodynamic settings (diamond shape)²⁰, and MORBs from the Pacific-Antarctic Ridge (PAR)¹⁷. Also shown are published data for the BSE²⁷ (2 s.d. analytical precision; average based on iron meteorites and igneous reference materials) and meteorites¹⁹. 2 s.d. analytical precision for individual chondrites is 0.13‰ and weathered chondrites are not shown, as they are associated with isotopic fractionation¹⁹. Literature data²⁷ are converted to δ^82/76Se following ⁴². Error bars for peridotites indicate 2 s.d. uncertainties of more than two combined measurements. If not available, the analytical uncertainty obtained for repeated analyses of peridotites is reported (± 0.10‰, 2s.d.) (see Methods). Shaded bars indicate the mean δ^82/76Se values of the BSE, and of enstatite and ordinary chondrites¹⁹, ± 2 s.d.