11.5: Lithification

Lithification

The transformation of sediments into sedimentary rock happens during lithification Links to an external site.. As sediments accumulate in the depositional environments, they are buried under more and more sediment. The sediments begin to compact under their own weight. Compaction Links to an external site., the squishing, of sediments, causes migration of water with dissolved ions. These ions become a natural glue, called cement, which precipitates and sticks sediments together, in a process called cementation Links to an external site.. Types of cement include carbonate (calcite), iron-oxide (hematite), and silica (quartz). Compaction and cementation must both occur for a sedimentary rock to form; without lithification, the sediment will not transform into a true rock (Figure 11.10).

The processes of compaction (left) and cementation (right) cause lithification producing a sedimentary rock.

Figure 11.10: Lithification turns sediments into solid rock. Lithification involves the compaction of sediments and then the cementation of grains by minerals that precipitate from groundwater in the spaces between these grains.  (CC-BY 4.0, Karla Panchuk Links to an external site.; modified by Emily Haddad)