Herstellung von >99,9997% 38Argon für die 40K-40Ar-Geochronologie

Abstract

For the conventional ⁴⁰K-⁴⁰Ar-dating method a very pure ³⁸Ar-spike is used as an internal standard for the mass spectrometric determination of the radiogenic ⁴⁰Ar content of the sample. By means of a 54 m long thermal diffusion column and a carrier gas of ³⁷Cl enriched HCl ³⁸Ar has been produced with < 10-⁵% ³⁶Ar and < 3・10^-4% ⁴⁰Ar. The chemical purity is > 99,99 % Argon. Spike corrections will no longer be necessary with this preparation and younger rocks can be dated which is essential for geologic problems of the Alps and contemporary mountain systems.