查看文章

Meteorites are interpreted as relics of early formed planetary bodies, and they provide information about the processes that occurred in the first few Myrs of our solar system. The ages measured for some differentiated meteorites (achondrites), indicate that planetesimals formed a differentiated silicate crust as early as≈ 3 Myr after the beginning of the solar system. The composition of the recently discovered achondrite Erg Chech 002 (EC002), the oldest andesitic rock known so far, betokens partial melting of a chondritic source taking place as early as≈ 1 Myr before all other known achondrites. However, thermal models of early accreted planetesimals predict massive melting of the planetesimal during core/mantle differentiation and cannot account for the preservation of a substantial amount of chondritic material. In this paper, we propose a way to interpret petrological and geochemical constraints provided by …