初期地球内部における物質分化：同位体地球化学と高圧融解実験からの制約

Abstract

We conducted isotopic model calculations and high-pressure melting experiments in order to estimate the major element composition of the “missing reservoir”, which is a supposed component that should compensate the difference in ¹⁴²Nd/¹⁴⁴Nd ratio between the bulk silicate Earth and carbonaceous chondrite, from which the Earth is assumed to have formed. Our estimation demonstrated that the missing reservoir should have picritic to komatiitic composition, and that it was likely to have been lost from the Earth's surface by a giant impact event at the last stage of the Earth formation.