Séminaire - First solids formed in the Solar System - Alexander Krot (Site Buffon)

IMPMC, Salle des élèves, 2^e étage, 61 rue Buffon, Paris 5 ^e

Jeudi 6 décembre 2018 à 14 h 30

Alexander N. KROT - Hawai’i Institute of Geophysics & Planetology, Université d’Hawaii ; Université de Copenhague ; Göthe Universität

Abstract

Refractory inclusions, are the oldest (4567.3±0.16 Ma) solids formed in the Solar System and are a minor component of chondrites and comets. Refractory inclusions formed by evaporation, condensation and aggregation in a gas of approximately solar composition in a hot ( > 1300 K) disk region exposed to irradiation by solar energetic particles, probably near the protoSun. Subsequently, some refractory inclusions were melted during transient heating events in their formation region, possibly by shock waves generated by disk gravitational instability. In this talk, I will review recent mineralogical and isotopic (Al-Mg, O) data on refractory inclusions to address the following topics: (1) the astrophysical setting of the Solar System formation, (2) the chronology of transient heating events in the protoplanetary disk (PPD), (3) the mechanisms of radial transport of solids in the PPD, (3) the mechanisms and timing of generation of distinct oxygen-isotope reservoirs in the PPD, and (4) the nature of oxygen-isotope heterogeneity in refractory inclusions from CV and CO carbonaceous chondrites.