cementationdominated

Cementationdominated is a term used in sedimentology and diagenesis to describe a regime in which cement precipitation is the primary control on porosity and permeability evolution after sediment deposition. In this context, secondary cementation processes outweigh the effects of compaction, dissolution, or replacement in shaping the pore network.

The mechanism involves the precipitation of minerals such as calcite, quartz, or dolomite within pore spaces, often during burial and diagenetic time scales constrained by pore-water chemistry, temperature, and fluid flow. The resulting intergranular or intragranular cements can significantly reduce porosity and permeability, though cementation can also stabilize the grain framework and preserve porosity in some cases by preventing extensive compaction. Cementing events may be early, coinciding with initial burial, or late, driven by changes in pore-water chemistry during deeper burial or tectonic activity.

Cementationdominated conditions are common in both carbonate and siliciclastic reservoirs. In carbonates, calcite or aragonite cements may fill vugs or pore spaces, while in sandstones the precipitation of quartz or carbonate cements can drastically reduce pore throats. The extent and distribution of cement determine reservoir quality, with pervasive, uniformly distributed cement often lowering permeability more than porosity.

Identification relies on petrographic analysis, thin section inspection, and mineralogical or geochemical signatures indicating pervasive cement networks as the dominant diagenetic product rather than dissolution or physical compaction alone.