What happens to the porosity of sedimentary rocks as they become more lithified?

As sedimentary rocks undergo lithification, which is the process of turning loose sediment into solid rock through compaction and cementation, their porosity typically decreases. This decrease occurs primarily due to the compaction of sediment. As sediments pile up over time, the weight of the overlying materials compresses the lower layers, forcing sediment grains closer together and reducing the space (pores) between them.

Additionally, during the cementation stage, minerals precipitate within these pores, further filling the spaces and reducing porosity. This combination of compaction and cementation inherently leads to a loss of pore space in the rock, resulting in decreased porosity. Understanding this concept is crucial, as porosity influences the rock's ability to store fluids and impacts its overall geological characteristics and behavior.