text: Some subfields of geochemistry are:
  *Aqueous geochemistry studies the role of various elements in watersheds, including copper, sulfur, mercury, and how elemental fluxes are exchanged through atmospheric-terrestrial-aquatic interactions.
  *Biogeochemistry is the field of study focusing on the effect of life on the chemistry of the Earth.
  *Cosmochemistry includes the analysis of the distribution of elements and their isotopes in the cosmos.
  *Isotope geochemistry involves the determination of the relative and absolute concentrations of the elements and their isotopes in the Earth and on Earth's surface.
  *Organic geochemistry, the study of the role of processes and compounds that are derived from living or once-living organisms.
  *Photogeochemistry is the study of light-induced chemical reactions that occur or may occur among natural components of the Earth's surface.
  *Regional geochemistry includes applications to environmental, hydrological and mineral exploration studies.