A Reappraisal of the 40Ar/39Ar Stepwise Degassing Technique
N. R. Brereton · Geophysical Journal International · 1972
The principal advantage of the 40Ar/39Ar dating method lies in the stepwise degassing technique. Despite the widespread use of the technique, each worker seems to adopt an individual criterion of choice, as to how the data should be treated, so as to extract the maximum amount of information from it. It was considered desirable to make a detailed analysis of the data taken during a number of stepwise degassing experiments to decide upon the most useful treatment of results. The basic principles of the technique are reviewed, and a method of data analysis is presented, which enables a detailed study of the argon liberation characteristics of the sample to be made. It also allows the age of the sample to be determined, such that no direct correction is made for atmospheric contaminant 40Ar. This avoids the fundamental assumption that all 36Ar, used to make this correction, is of atmospheric origin.