THE MAXIMUM AGE OF THE ELEMENTS AND THE AGE OF THE EARTH'S CRUST

Abstract
Estimates are given of a maximum time of formation of the elements of 5.5 billion years and of the time of formation of the earth's crust at 3.5 billion years. These estimates were based on the isotopic constitution of lead ores dated from isotopic analyses of radiogenic leads from uranium minerals. Methods of calculation are described.Experimental measurements of the isotopic constitution of lead from mass spectrograms of lead tetramethyl are reported with examples.