The Melting-Differentiation of Chondrite and Initial Evolution of Earth

On the basis of elementary knowledge of meteoritics and the theory of solarsystem evolution, the primary matter of the earth was proved to be composed of various nebular condensates similar to each group of chondrites.The melting-experiments of chondriteat high pressure show that chondrite undergoes two major differentiation stages under high temperature and high pressure.In accordance with these results,the initial evolution of the earth is inferred:the original earth consisted of Fe-Ni inner core and quasi-chondrite original mantle. The first differentiation of original mantle resulted in the formation of Fe-Ni-S(P,C) outer core, then the second differentiation of mantle created two types of original crust——Si, Al-rich and Ca, Al-rich.