RADIOGEOPHYSICS AND THE AGE OF THE EARTH

The development of radiogeophysics is briefly discussed, and its fundamentals are indicated. The different cases of utilization of radioactive constants for absolute age determinations are discussed. The conditions for the applications of these methods are described. A special discussion is presented of the lead isotopic method of age determinations. The principal works published on determination of the age of the earth are considered briefiy. (J. S.R.)