High temperature heat content and heat capacity of silicate glasses: experimental determination and a model for calculation

Knowledge of the thermodynamic properties of silicate melts is fundamental to quantitative characterization of igneous systems. This paper presents new data on one of these properties, heat content, for silicate glasses and supercooled silicate liquids and derives partial molar heat contents for the glasses. The high temperature heat contents of two FeO-rich synthetic silicate glasses and five glasses and three supercooled liquids prepared from igneous rocks ranging from basalt to rhyolite were measured by drop calorimetry. Heat capacities of silicate liquids and the change in heat capacity at the glass transformation are discussed.