Geochemistry is concerned with the laws governing the distribution of the chemical elements and their isotopes throughout the Earth. As a concept it has been recognized for 130 years but it has grown into a separate Earth science during this century. Geochemistry has mutual links with many neighbouring disciplines. Its present field of activity is determined by many problems of broad interest and by the availability of methods. Several exterior influences have recently developed. Thus, nuclear physics and its specific measuring techniques made isotope geochem­ istry possible, while space research has stimulated the development of cosmochem­ istry. Except a few \"standard\" materials as Gland W 1 there is no other rock on earth whose composition is as well known as that of meteorites colliding with our planet on their cosmic course. Biochemistry is linked with the rapidly developing new branch of organic geochemistry. Our discipline has moved forward in step with the advancement of analytical chemistry. When optical and X-ray spectrochemical analysis came into use and with the discovery of natural and artificial radio-activity, many new elements were identified. With the development of spectrophotometers, radiation counters and nuclear sources over the last 20 years, a flood of analytical data on geological sub­ jects has been released, and we ought to make use of it. | Handbook of Geochemistry by K. H. Wedepohl, Paperback | Indigo Chapters