Effect of Temperature and Gas Phase on the Crystallization and Mineral Composition of Dacite-Type Volcanic Rock

Abstract

Computer-based physico-chemical modeling was used to analyze melting and crystallization processes in the natural Si–Ti–Al–Fe–Mn–Mg–Ca–Na–K–O system, which corresponds to an acidic volcanic dacite rock. The presence of volcanic glass and the disequilibrium of minerals in dacite phenocrysts hinder the instrumental determination of mineral composition and melt behavior. The methods applied here, based on chemical analysis data and computer modeling, make it possible to calculate the compositions of the solid phases and melts formed under various conditions and to select an optimal approach for rationally modifying the composition of magmatic rocks in the production of cast stone, ceramics, and mineral fibers.