Thermodynamic and rheological properties of rhyolite and andesite melts

A study on the viscosity and heat capacities of rhyolite and andesite glass and melt was conducted through relative enthalpy measurements between 400 and 800 Kelvin. The melts were used due to the relative simplicity of their chemical compositions. The results confirmed that the heat capacity and enthalpy of silicate glasses can be predicted using the oxide empirical coefficients. Heat capacities of the silicate melts were dependent on the melt composition and exhibited complicatedtemperatures due to the reaction between the aluminum and alkali elements at different temperatures.