geochimica

Geochimica, or geochemistry, is the science concerned with the chemical composition of the Earth and the chemical processes that govern the distribution and movement of elements within and between rocks, soils, water, the atmosphere, and biological systems. It investigates how elements cycle through the planet’s reservoirs over time and how isotopic variations preserve records of formation, weathering, climate, and life.

Modern geochemistry emerged in the late 19th and early 20th centuries, building on mineralogy and chemistry. Vladimir Vernadsky and, especially, Victor Goldschmidt helped establish the field’s conceptual framework, including the distribution of elements and the thermodynamics of minerals. The development of isotopic techniques, mass spectrometry, and radiometric dating broadened the scope to include trace elements and age information.

Geochemical research uses field sampling, laboratory analyses, and numerical modeling. Core tools include mass spectrometry, optical and laser-based spectroscopy, chromatography, and isotopic dating to quantify element abundances, isotopic ratios, and mineralogical associations. Researchers study weathering, soil formation, groundwater chemistry, ore genesis, pollution transport, and elemental cycles in oceans and the atmosphere.

Subfields encompass elemental geochemistry, isotopic geochemistry, organic geochemistry, aqueous geochemistry, environmental geochemistry, marine geochemistry, cosmochemistry, and planetary geochemistry. Applications span mineral exploration, environmental assessment and remediation, hydrology and water quality, climate and biogeochemical cycles, archaeology, and the study of other planetary bodies.