Volatilization of alkali metals from the heated Murchison (CM2) meteorite

In order to examine volatilization processes of alkali metals at high temperature, heating experiments were carried out using a starting material prepared from Murchison (CM2) (grain-size : ∿10μm) at temperatures of 1200-1400℃ under a constant pressure of 8×10^ Torr, and heating duration up to 80min. Analyses of alkalis (Na, K, Rb), major and minor elements and petrographic examinations were performed for run products. Results show that fractional volatilization of alkali metals occurred during heating. It is suggested that the volatilization rates of alkali metals are influenced by the chemical composition of partial melt.