Regional geochemistry is the study of the spatial variation in the chemical composition of materials at the surface of the Earth, on a scale of tens to thousands of kilometres.
Important parameters to consider when designing or evaluating a geochemical survey are: Garrett et al. (2008) describe how the discipline has evolved from its beginnings in Russia in the 1930s.
In recent years, many surveys have emphasised a more broad-based environmental mapping approach.
Numerous government agencies around the world have initiated multi-year systematic geochemical mapping projects, aimed at producing baseline geochemical maps of very large areas.
See, for example, the description by Johnson et al. (2005) of the British Geological Survey’s G-BASE project.