Re-examination of problems associated with experimental studies on the secular variation of the 40Ar/36Ar for the terrestrial atmosphere and the Earth's interior

Abstract

Secular variation of the ⁴⁰Ar/³⁶Ar of the terrestrial atmosphere and the Earth's interior gives a significant information on the degassing history of the Earth and several models have been proposed about it. However,such experimetal data on the past 40Ar/36Ar as are reliable to check such models are quite limited. In this study, I will discuss about reasons why it is not easy to get reliable ⁴⁰Ar/³⁶Ar in the past together with some cautions during data acquisitions.