Chemical principles applied to Earth materials open a window into processes past and present. Geochemistry studies the distribution and movement of chemical elements and their isotopes in rocks, soils, water, and the atmosphere. It links mineralogy, petrology, and environmental science.

Major-element analyses reveal rock types and differentiation processes. Trace elements and isotopes track magma sources, fluid pathways, and temperatures of formation. Organic geochemistry examines the transformation of carbon compounds into petroleum and coal. Environmental geochemistry addresses contamination and nutrient cycling.

Modern instruments such as mass spectrometers and electron microprobes allow precise measurements on tiny samples. Geochemical data constrain models of mantle convection, crustal growth, and climate change. The field continually expands as new analytical techniques become available.

• Study of chemical composition and processes of Earth
• Uses elements and isotopes as tracers
• Applied to rocks, fluids, and the environment
• Relies on advanced analytical instrumentation