Unpublished Abstract

Bina, C. R., A note on jadeite-diopside solubility in garnet at 13 GPa, unpublished manuscript, 1995.

Abstract. We have experimentally confirmed that pyroxenes along the CaMgSi₂O₆-NaAlSi₂O₆ join begin to dissolve into garnet-majorite solid solution at pressures of 13 GPa and temperatures of 1200-1600°C, confirming the early results of Ringwood and Major (1971). At this pressure, jadeite dissolves into garnet, by NaSi coupled substitution, preferentially to diopside. The Mg/Ca ratio of the resulting garnet solid solution increases with increasing temperature. These results are consistent with the results of Gasparik (1989) on the Mg₂Si₂O₆-CaMgSi₂O₆-NaAlSi₂O₆ system. The observed Ca-Mg partitioning is consistent with the negative Clapeyron slopes of the pyroxene-majorite phase transformations and with the greater solubility in garnet of enstatite relative to diopside at these pressures.