This chapter presents basic information on the age of the crust and the lithospheric mantle and provides a brief description of geochronological methods used in the geosciences. Full descriptions and technical details of these methods can be found in monographs by Faure (1986) and Dickin (1995) and in the recent reviews by Banner (2004) and Patchett and Samson (2004). Additional details can be found in Albarède, 2003, while a brief description of practical approaches is given in Fowler (2004).

Introduction to isotope geochronology

Geochemical classification of elements

Lithophile, siderophile, and chalcophile elements

The most widespread geochemical classification of elements has been proposed by Victor Moritz Goldschmidt (e.g. Kaufman, 1997). In Goldschmidt’s classification, the chemical elements are grouped according to their preferred host phases into four categories:

• lithophile (silicate loving) elements,

• siderophile (iron loving) elements,

• chalcophile (sulfur or copper loving) elements, and

• atmophile (gas loving) elements.