Geochemisch

Geochemisch, or geochemical in English, is a branch of geoscience that studies the chemical composition of Earth and the processes that control the distribution and transformation of elements and isotopes in natural materials. It combines principles of chemistry, geology, and physics to understand how elements occur in rocks, minerals, soils, water, and air, and how these inventories evolve over time.

Key topics include geochemical cycles (for example carbon, sulfur, and trace elements), petrogenesis and metamorphism, hydrogeochemistry, marine geochemistry, and cosmochemistry. Isotope geochemistry uses isotope ratios to infer ages, sources, and physico-chemical conditions under which materials formed or were altered.

Methods in geochemistry range from field sampling and qualitative characterization to advanced laboratory analyses. Common instrumental techniques include inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray fluorescence (XRF), X-ray diffraction (XRD), and isotope ratio mass spectrometry (IRMS). Geochemical modelling, numerical simulations, and laboratory kinetic experiments complement observational data to interpret processes.

Applications of geochemisch are wide and interdisciplinary. They include mineral exploration and ore deposit genesis, environmental geochemistry and contaminant transport, groundwater and soil quality assessment, palaeoenvironmental reconstruction, and studies of volcanic, hydrothermal, and planetary systems. The field also underpins archaeology through sourcing and dating of materials and contributes to understanding climate change via isotopic records.

Historically, the discipline matured in the late 19th and early 20th centuries, with influences from figures such as V. I. Vernadsky and Arthur Holmes, who advanced isotopic methods and the concept of geochemical cycles. Today, geochemisch integrates analytical chemistry, field work, and modelling to analyze Earth and planetary materials.