diagenesis All the changes that take place in a sediment at low temperature and pressure after deposition. With increasing temperature and pressure, diagenesis grades into metamorphism. Diagenetic processes such as compaction, dissolution (see PRESSURE DISSOLUTION), cementation, replacement, and recrystallization are the means by which an unconsolidated, loose sediment is turned into a sedimentary rock, e.g. sand into a sandstone, or peat into coal. See also CARBON ISOTOPES; and OXYGEN ISOTOPES.

diagenesis All the changes that take place in a sediment at low temperature and pressure following deposition. With increasing temperature and pressure, diagenesis grades into metamorphism. Diagenetic processes such as compaction, dissolution, cementation, replacement, and recrystallization are the means by which an unconsolidated, loose sediment is turned into a sedimentary rock (e.g. sand into sandstone, or peat into coal).

diagenesis Physical and chemical processes whereby sediments are transformed into solid rock, usually at low pressure and temperature. Pressure results in compaction, forcing grains together and eliminating air and water.

diagenesis See taphonomy.