Because Austin's essay is older, we can probably assume that these copying errors originated with him.
Rather than checking the accuracy and relevancy of Austin's quotations from Dalrymple (1969), Snelling and Swenson simply uncritically parroted and perpetuated Austin's mistakes in their later web essays.
Indeed, if Dalrymple’s data is representative, 3 times out of 26 the K-Ar method will give a too young date (though by only an extremely trivial amount for a rock that is really millions of years old).
The one case that would have produced a significant error, the Hualalai flow in Hawaii, was expected (see the previous essay). Naughton, 1968, 'Radiogenic Helium and Argon in Ultramafic Inclusions from Hawaii,' J.
In addition, excess argon is even less of a problem with Ar-Ar dating, where excess argon can often be distinguished from radiogenic argon and its effects eliminated (Mc Dougall and Harrison, 1999, p. , Snelling failed to properly quote the 'apparent K-Ar dates' from Table 2 in Dalrymple (1969, p. That is, Snelling mistakenly listed the concentrations of 40Ar (in 10 to the -12 moles/gram) for the Hualalai, Mt. Lassen, and Sunset Crater samples as their apparent K-Ar dates!!