as sediments are buried deeper, load pressures become greater resulting in tight grain packing and bed thinning. this causes increased pressure between grains thus increasing the solubility of grains. as a result, the partial dissolution of silicate grains occurs. this is called pressure solutions. chemically speaking, increases in temperature can also cause chemical reaction rates to increase. this increases the solubility of most common minerals (aside from evaporites). furthermore, beds thin and porosity decreases allowing cementation to occur by the precipitation of silica or carbonate cements into remaining pore space.