MEASUREMENT AND APPROXIMATION OF THE AGE SPECTRA OF ROCKS AND MINERALS DURING 40Ar/39Ar DATING
D.V. Alekseev1,2, A.V. Travin1,2
1S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
Keywords: Ar/Ar dating, age spectrum, inverse problem, Fredholm integral equation
Abstract
During 40Ar/39Ar dating, the age spectrum of the sample can be seriously distorted because of the averaging of its Ar isotope composition over the portion of the released gas. New methods of age spectrum approximation with suppression of distortions have been elaborated. The efficiency of these methods is experimentally demonstrated. A new method for measurement of age spectra with high resolution by the portion of the released gas is proposed. The method is based on the experimental data and permits refining of the age spectrum or its fragments. The applicability and efficiency of this method are also shown experimentally. The proposed method can be used not only to measure the age spectra during 40Ar/39Ar dating but also to measure other isotope characteristics of the rock and mineral samples during the stepwise separation of the analyte.
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