| Abstract |
Chondrules are millimeter-sized and spherical-shaped crystalline grains consisting mainly of silicate material. They are considered to have formed from molten droplets about 4.6 billion years ago in the solar nebula; it is believed that they melted and cooled again to get solidification in a short period of time. They must have great information about the early history of our solar system. We are numerically modeling the solidification process based on a phase-field model, which is one of the powerful models to numerically solve the first-order phase transformations. We investigated the formation process of barred-olivine (BO) texture observed in chondrules. Our numerical simulation showed that the parallel-set of olivine bars form due to the Mullins-Sekerka instability during the rapid cooling of a silicate melt. These results suggested that the BO chondrule cooled much faster than that expected before. |
