Temperature evolution of pore solutions in equilibrium with rocks of various silica contents

Computer modeling of the interaction of water with rocks of various silica contents (from granite to dunite) allowed us to reveal some important parti culars and properties of the equilibrium pore solutions of these rocks at T and P from 25 degreesC (0.001 kbar) to 800 degreesC (5 kbar). It was shown that horn solidus temperatures to 500-400 degreesC the pore solutions of a ll rock varieties were close to each other in chemical compositions, pH, an d f(H2). Below 500-400 degreesC, a progressive differentiation of the compo sitions, alkalinity, and redox potential of pore solutions in equilibrium w ith rocks of various silica contents was established. The modeling revealed principal features in changes of solid phase parageneses equilibrated with pore solutions with decreasing T and P, particulars of redox reactions in closed rock-water systems, and the capability of an intense gas release (CO 2, CH4, H-2, and others) in reactions of these systems. The results of mode ling could be of interest for researchers who study hydrothermal ore deposi ts.