Estimation of crystallization proportions and the equilibrium/disequilibrium of quench experiments in the basite systems

Original program based on Huang algorithm was used to calculate the concentrations of coexisting phases in quench experiments with the known bulk compositions of systems and phases. Using this procedure, we rejected the disequilibrium experiments from experimental series with the similar bulk (starting) composition of charge and calculated crystallization proportions for the olivine-plagioclase and olivine-plagioclase-augite cotectics. The statistically valid dependence was established for the first time between crystallization proportions for the olivine-plagioclase cotectics and #An of the melt. Experimentally obtained data on the Ol-Pl and Ol-Pl-Aug crystallization proportions were compared with values obtained by numerical simulation of the equilibrium crystallization of basaltic melts using COMAGMAT software. It was shown that the basic version COMAGMAT-3.5 Program with a standard set of liquidus thermometers satisfactorily reproduces the crystallization proportions in these cotectics for basaltic melts. Simulation of crystallization for more silicic magmas requires calibrating liquidus thermometers for modeled compositional range. Only single experimental estimates were obtained for other cotectics.