DISTRIBUTION OF FE2+ AND MG BETWEEN COEXISTING ILMENITE AND PYROXENE WITH APPLICATIONS TO GEOTHERMOMETRY

This study presents an experimental calibration of the orthopyroxene-ilmenite and clinopyroxene-ilmenite geothermometers. It has been shown that the Fe**2** plus minus Mg distribution between the two phases is dependent on temperature, pressure, and, significantly, on the compositions of the coexisting solid solutions. Initial comparison of the ilmenite-pyroxene thermometers with each other and with other thermometers on natural samples gives fair to good agreement. In the ilmenite-pyroxene geothermometers, significant components yet to be explored experimentally include Fe//2O//3 in ilmenite and CaSiO//3 in clinopyroxene.