The oceans of the world represent a natural depository for the dissolved and particulate products of continental weathering. After its input, the dissolved material consolidates by means of biological and geochemical processes and is deposited on the ocean floor along with the particulate matter from weathered rock. The ocean floor deposits therefore embody the history of the continents, the oceans and their pertaining water masses.

The field of marine chemistry and geochemistry has developed dramatically since the end of World War II. Mainly this spurt of refinement was the consequence of the development of novel techniques of measurement of both radioactive and radiogenic isotopes as well as the light stable isotopes.