http://www.ens-lyon.fr/Planet-Terre/Infosciences/Geodynamique/Chimie-enveloppes/Articles/composition.htmld'après Allègre et al. 1995 en fraction massique d'éléments (pd%) Terre globale O = 32.4 Fe = 28.2 Si = 17.2 Mg = 15.9 Mn = 0.3 Cr = 0.27 Na = 0.25 Ca = 01.6 Al = 01.5 Ni = 01.6 Ti = 0.07 K = 0.02 Terre silicatée globale O = 44.8 Mg = 22.78 Si = 21.5 Fe = 05.82 Ca = 02.31 Al = 02.16 Cr = 0.27 Na = 0.26 Ni = 0.20 Mn = 0.12 Ti = 0.11 K = 0.03 noyau Fe = 79 Si = 07 Ni = 05 O = 04 S = 02.3 en ppm : Cr = 8 000 Mn = 5 800 P = 3 700 Co = 2 500
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