Geokemia

Geokemia is the scientific study of the chemical properties, composition, and processes that govern the Earth and its environments. It focuses on how elements are distributed among rocks, minerals, soils, waters, and the atmosphere, and how geological processes such as weathering, magmatic differentiation, metamorphism, and sedimentation alter chemical inventories over time. The field integrates principles of chemistry with geological context to explain the evolution of the planet’s chemical system.

Geokemia employs a range of methods to analyze materials and environments. Analytical techniques include mass spectrometry, X-ray fluorescence, inductively coupled plasma emission spectroscopy, and isotope ratio measurements. Researchers collect field samples, conduct laboratory experiments to simulate conditions, and develop computational models to understand chemical reactions, transport, and phase changes under varying temperatures, pressures, and redox conditions.

Subfields within geokemia include hydrogeochemistry, which studies chemical interactions between water and rocks; petrogeochemistry and mineral chemistry, which examine the chemical composition of rocks and minerals and their formation histories; isotope geochemistry, which uses isotopic ratios to trace sources and ages; geochemical thermodynamics and kinetics, which model stability and reaction rates; and environmental geochemistry, which assesses chemical processes in soils, sediments, and contaminated systems.

Geokemia has historical roots in the broader development of geochemistry and modern analytical chemistry. It informs interpretations of natural element cycles (such as C, H, O, S, and Si), guides mineral exploration and resource management, and supports environmental monitoring, remediation, and climate-related research. The discipline often intersects with geology, chemistry, hydrology, and environmental science to address complex Earth system questions.