Figure 2.

The CI chondrite-normalized estimated abundances of H, C, N, noble gases and volatile lithophiles in the bulk Earth. Within the uncertainties, the volatile element abundances are consistent with a 2–4% CI contribution to a largely volatile-depleted proto-Earth. The depletions in N and Xe could be due to an underestimate of the N content of the Earth and loss of Xe from the atmosphere to space, respectively (see the text for details). The terrestrial abundances of H, C, N and noble gases are from Marty [47], and the volatile lithophile abundances are from Palme & O'Neill [51] except for I that is from Deruelle et al. [52]. The CI chondrite H, C and N abundances are from Alexander et al. [23], while all other elements are from Lodders [53].