This paper describes a model and gives computer simulations in two dimensions of coupled fluid flow, compaction, hydrofracturing, deposition, and subsidence in sedimentary basins. The mechanism of compaction used is a water-film diffusion model of pressure solution for quartz in a periodic array of truncated spheres. Although this process is not the only possible compaction mechanism, it is important in quartz-rich sandstones and illustrates the coupling of overpressuring and diagenesis. Results of simulations show that regions of overpressure can encompass several lithologies with the upper transition to normal pressure cutting across dipping beds, which were deformed by differential tectonic subsidence. Some compartments are enclosed within individual beds, sealed by greater compaction on the margins of the beds. Interiors of these overpressured compartments become fractured and much more permeable as the fluid pressure exceeds the sum of the horizontal stress and rock strength. Compaction and thermal expansion of the fluid combine to cause overpressuring that slows down the rate of compaction by reducing stresses on grain contacts. Rocks surrounding the