Diagênese

Diagênese is a geological process involving the final stages of sediment lithification and the development of a rock’s internal structure after initial sediment compaction and cementation. The term originates from Greek, meaning "dividing" or "separating," and it describes the transformations sediments undergo to become consolidated sedimentary rocks.

During diagênese, sediments experience various physical, chemical, and biological processes that refine their mineral composition and texture. These processes include recrystallization, where minerals grow and change shape, and neomorphism, which alters existing minerals into new types without melting. Diagênese also encompasses the formation of secondary mineral deposits such as

pyrite, calcite, or silica fill-ins within pore spaces, further consolidating the rock matrix.

This process is influenced by factors like pressure, temperature, fluid activity, and the chemical environment within sediment layers. Diagênese can occur over a range of depths—from near-surface environments to deeper burial conditions—affecting the porosity and permeability of sedimentary rocks, which are critical parameters in hydrogeology and petroleum geology.

In geological stratigraphy, diagênese is considered a key factor in the diagenetic history of sedimentary basins, impacting reservoir quality and mineral deposits. Understanding diagênese helps geologists interpret past depositional environments and the geological history of sedimentary formations.

Overall, diagênese plays a crucial role in transforming unconsolidated sediments into durable rock formations, influencing the structural, mechanical, and chemical characteristics of sedimentary rocks in the Earth's crust.