Thermal buffering in the orogenic crust

Abstract

Metamorphic rocks evolve through chemical reactions that consume energy in order to advance. Melting reactions in particular are strongly endothermic and may consume a substantial proportion of the orogenic heat budget. While this has been established qualitatively, modern thermodynamic data sets allow quantification of the thermal consequences for real rocks. Here we calculate the heat consumption of melting reactions, and its effect on the temperature attained during high-grade metamorphism, for two compositional end members that are representative for the orogenic crust. Fertile metapelites are volumetrically minor but petrologically significant because pressure-temperature-time-deformati..