A reference to the study of the chemical composition of the various phases of the Earth and the physical and chemical processes which have produced the observed distribution of the elements and nuclides in these phases: Geochemical investigations are concerned with the chemistry of the Earth, including the rocks, sediments, and soil that constitute the solid Earth and the fluids which compose the oceans, inland waters, and the atmosphere.

In geochemistry, an unusually high concentration of one or more chemical elements in a sample of rock, soil, vegetation, or water: A geochemical anomaly is a high concentration of hydrocarbons in soil which often indicates a nearby mineral deposit.

The study of the global distribution and the migration of a particular element, mineral, or compound, including the amount liberated by weathering and transported to the Earth sediments and oceans: One example of geochemical balance can be exemplified by the distribution of quartz in igneous rocks, its liberation by weathering, and its redistribution into sediments and in solutions, into lakes, rivers, and oceans.

Sediments refer to solid fragments of inorganic or organic material that come from the weathering (disintegration and decomposition) of rock and are carried and deposited by wind, water, or ice.

In Earth science, the successive stages in the circulation and migration of chemical elements among the lithosphere, hydrosphere, and atmosphere during geological changes: The geochemical cycle is the route or the course that chemical elements travel in the surface and crust of the planet Earth.

Over geological time any change in the chemical composition of some section of the Earth: Geochemical evolution is an important factor in the oceans.

Geochemical evolution is any alteration or change in the chemical composition of a rock in which the amount of a particular component exceeds the amount present in the parent rock.