The evolution of the permeable-impermeable boundary within the Earth's crust affected by precipitation of silica minerals

Abstract

The spatial and temporal variations in permeability within the Earth's crust are affected by mineralogy and kinetics of silica precipitation. Calculation of quartz solubility at the Kakkonda geothermal field and the hydrothermal experiments of silica precipitation indicate that the permeable-impermeable boundary within the Earth's crust could be reproduced by precipitation of silica minerals via nucleation faster than the permeable shallower part where quartz growth on quartz surfaces occurs mainly. Kinetics of silica-water interaction including both surface reaction and nucleation is needed to consider the evolution of the hydrological conditions within the Earth's crust.