Geochemistry incompatible elements

Fig. 4. Geochemistry of the greenstone belt volcanic rocks. Data are from Scholey (1992) and Brake (1996) for the Belingwe belt, from Horstwood (1998) for the Midlands belt, and from Tomschi (1988) and Jelsma (1993) for the Harare belt. (Note the difference in geochemical fingerprint of the basalts, andesites and rhyodacites of the Belingwe, Midlands and Harax belts in terms of MgO contents and primitive mantle-normalized incompatible elements.) Normalizing values are after Wood (1979) and Yb after Holm (1985).

Nevertheless, we can make some general statements about the geochemistry of differentiated planets. The planetesimals from which they accreted had compositions determined largely by element volatility. Once assembled into a planet and heated, the partitioning of elements into cores and mantles was governed by their siderophile or lithophile affinities. Further differentiation of mantles to form crusts was controlled by the compatible or incompatible behavior of elements. 

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