Geochemistry is the study of the chemical makeup and processes of the earth, from its deep interior to its oceans and atmosphere. Despite the name, it also includes studying the chemical compositions and processes taking place on other planets.
Geochemistry merges geology with chemistry. Geology is the study of the earth's physical structure, and chemistry explores the properties of substances and their reactions. Rather than just asking how a mountain formed, a geochemist asks what chemical elements the rocks contain and how they interact with the environment. This field is essential for understanding everything from volcanic eruptions to the chemical conditions required to support life on Earth and potentially on other planets.