An investigation has been made of the isotopic composition of the argon from four potassium minerals. In each case a high A⁴⁰/A³⁶ ratio compared to that of atmospheric argon is observed showing directly that K⁴⁰ decays to both Ca⁴⁰ and A⁴⁰. From the absolute amounts of radiogenic A⁴⁰ and K⁴⁰ in the minerals a lower limit on the branching ratio λKλ_β can be made. If the half-life, 7×{}10⁸ yrs., is assumed for K⁴⁰{→}Ca⁴⁰, λKλ_β must be at least 0.02. The possibility of using this method for measuring geological age is suggested.
No takes yet. Share an insight, caveat, or question.
Aldrich et al. (1948) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: