Petrogenese

Petrogenese, or petrogenesis, is the study of the origin and formation of rocks, focusing on the processes that generate their minerals, textures, and chemical compositions. It seeks to explain why rocks have particular properties and how they relate to Earth's history.

The field covers igneous, metamorphic, and sedimentary rocks, analyzing parent sources, cooling histories, pressure–temperature paths, and diagenetic or metamorphic overprints. It situates rock formation within broader tectonic and geodynamic settings.

Igneous petrogenesis examines partial melting of existing rocks, crystallization of minerals from silicate melts, and processes that modify magmas such as fractional crystallization, assimilation, and magma mixing. It links geochemical signatures to source rocks and tectonic context.

Metamorphic petrogenesis studies mineralogical transformations produced by elevated pressure and temperature, including phase equilibria, dehydration reactions, and metasomatism. It uses mineral assemblages and thermobarometry to infer pressures, temperatures, and timescales of metamorphism.

Sedimentary petrogenesis considers diagenesis and lithification that convert unconsolidated sediments into rock, as well as diagenetic alterations and the influence of provenance, transport, and deposition on rock composition and texture.

Methods commonly employed include petrography, geochemistry, isotope systems, and experimental petrology, complemented by thermodynamic modeling and geochronology to reconstruct formation conditions and histories.

Significance lies in interpreting crustal evolution, tectonic processes, resource potential, and the broader geological history of regions and continents.