Compaction and diagenesis of sandstones - the role of pressure solution

A model is presented for the compaction of granular aggregates that accommodates the serial processes of grain-contact dissolution, grain-boundary diffusion, and precipitation at the pore wall. Impor-tantly, this treatment follows the progress of grain interpenetration as contact areas grow, mass transport lengths increase, and rate-limiting processes may switch with the progress of compaction. A simple repeating closed system incorporates two stressed grains in contact and enables the progress of compaction, and the evolution of the mass concentration of the pore fluids to be followed with time, for arbitrary mean stress, fluid pressure, and temperature conditions. Hindcast comparisons with experimental results for the compac-tion of quartz sand in a closed system (Elias and Hajash, 1992) show excellent agreement for rates of change of porosity, the asymptotic long-term porosity, and for the development of silica concentrations in the pore fluid with time.