Cementation

Cementation is a diagenetic process in sedimentary geology in which dissolved minerals precipitate from groundwater and bind sediment grains together, leading to lithification and the formation of cemented rocks such as sandstone and limestone.

Cements commonly form from minerals such as calcite, silica, dolomite, and iron oxides. Cementation occurs when pore waters become supersaturated with these constituents or undergo mineralogical changes during burial and diagenesis. It often proceeds after compaction reduces pore space, and it can take place over long timescales—from thousands to millions of years.

Cementation affects rock properties by increasing strength while typically reducing porosity and permeability. The specific cement type and its distribution determine a rock's texture and pore structure, influencing fluid flow and reservoir quality in hydrocarbon systems.

In sedimentary rocks, cementation is a principal mode of lithification, acting alongside compaction and, where applicable, recrystallization or dissolution–reprecipitation processes.

In metallurgy, cementation describes diffusion-based carburization: heating iron with carbon-rich materials (such as charcoal or coke) so carbon diffuses into the surface and produces steel or hardened surface layers. This historical process underpinned early steel production and the manufacture of cemented or carburized metals.

The term cementation derives from the notion of binding, from Latin caementum, and, while it has these distinct meanings, both senses relate to the idea of cementing or binding materials together.