5:15 PM - 7:15 PM
[SIT21-P02] From planetesimals to planetary embryos: clues from differentiation of enstatite chondritic body
Keywords:Enstatite chondrite, high-temperature and high-pressure experiment, proto- Earth, core-mantle differentiation, Al-Mg system
Chondrites are snapshots of the early solar system, providing key insights into how primitive planets formed and evolved. It has been a hot issue that enstatite chondrites may have formed from the same reservoir as the Earth from the isotopic composition point of view. The debate on the redox condition of the Earth’s interior, especially at the core-mantle boundary, also gives enstatite chondrites opportunity to serve as the potential building blocks for large portions of the proto-Earth. However, little has been discussed about the status of the enstatite chondritic materials in the early solar system. This study presents experimental studies on the differentiation process of EH3 enstatite chondrite (Sahara 97096). The results show that the melting temperature of this enstatite chondrite meteorites is about 200 ℃ lower than that of pyrolite (KLB-1), and lower than that of Allende carbonaceous chondrite. Computerized tomography analysis on quenched samples shows that metallic liquid is separated from the silicate residuals as long as the degree of partial melting closes to 40 %. Synthesize the results of this study with the heat produced by the short decay system (Al-Mg), we suggest that large proportion of enstatite chondritic materials in the solar system may have served as building materials for planetesimals which then differentiated and form a magma ocean.