Chondrule formation process: Constraints from 26Al ages and cosmochemical properties of chondrules in a primitive chondrite

Abstract

²⁶Al ages of FeMg chondrules in a primitive CO chondrite are similar to those in the least equilibrated ordinary chondrites (1.0-2.5Ma after CAI formation). Bulk chemical compositions of the CO chondrules have higher FeO contents relative to those of ordinary chondrite chondrules. CO chondrules formed contemporaneously with ordinary chondrite chondrules in a different redox condition in early solar system. Using behaviors of silicates, organics and H₂O ices with distance from the Sun in a protoplanetary disk and its time evolution, we propose an qualitative chondrule forming model.