Department of Earth Sciences, Faculty of Science, Kobe University/Department of Earth Sciences, Faculty of Science, Kobe University
Abstract
In order to examine vaporization behavior of sodium for partially molten chondritic materials, heating experiments were carried out using two starting materials prepared from the Etter (L5) chondrite (grain-sizes : sample A, φ torr, and heating duration up to 160min. Chemical analyses and petrographical examinations were carried out for starting materials and run products. The rates of vaporizations for sodium were estimated for partial melts (degree of melting=11-34%) at 1200-1400℃. Differences in the vaporization rates for the partially molten charges obtained from different starting materials were not detected clearly at the same temperatures. Systematically different trends of sodium vaporization rate are found between those obtained in this work and those previously reported for total melts (at 1450-1600℃) from similar starting materials (TSUCHIYAMA et al., 1981). It appears that the vaporization mechanism of Na is basically the same in the temperature range from 1200 to 1600℃ for partially to completely molten charges