K/Ar dating of lunar soils III: Comparison of 39Ar-40Ar and conventional techniques: 12032 and the age of Copernicus

Abstract

We have previously reported conventual K, Ca, and Ar analyses for grain-sized separates of 12033,42; 15531,42; and 67701,22 (Alexander et al., 1976) and Ar and Ca analyses for grain-sized separates of 70181,30 (Pepin et al., 1975). Aliquots of the grain-sized separates of these four soils remained in our allocation of lunar samples. These four soils were selected for 39 Ar-40 Ar total fusion analyses since the resulting data would be directly comparable to our conventional determinations.