established in the earliest history of the planet or as the result of a continuing supply of water and the constituents of sea water by degassing from the Earth’s interior. In 1951 . Rubey, in his Presidential Address to the Geological Society of America, took the latter point of view. His arguments were colored by the knowledge available at that time of the age of the Earth and the age of the oldest rocks. Based on the analysis of lead isotopes in galenas, it was determined in the late 1940s that the Earth was about billion years old. Some continental rocks, presumed to be relicts of ancient terrains, dated at about.
