DETERMINATION OF ABSOLUTE GEOLOGIC AGES BY
THE POTASSIUM-ARGON METHOD, NEUTRON ACTIVATION ANALYSIS BEING USED FOR DETERMINING THE RADIOGENIC ARGON

M. SOROIU, M. CEREI, M. ONCESCU, A. DANIS and C. MANTESCU
The Institute for Atomic Physics of the Academy of the Romanian People's Republic, Bucharest

After the general principle of the radioactive methods used to determine the absolute geologic time is briefly shown, the principle of the method for determining radiogenic argon by using activation analysis is expounded.
The authors describe in detail the working stages of the method for determining radiogenic argon by activation in the variant elaborated at the Bucharest Institute of Atomic Physics: preparation of the sample vial, of the standard vial, introduction of the radioactive argon in Geiger-Müller counters and measurement of its activity.
The checks to which the method was subjected are shown: measuring the activity of blank samples, determining known quantities of argon and comparing the age determinations obtained, on the same samples, by the method described in this paper and by the classic determination methods of radiogenic argon.
The results of all these checks allow the conclusion to be drawn that the method elaborated at the Institute for Atomic Physics for determining radiogenic argon is correct and can be applied to the series determination of absolute geologic ages.