Even that significant error is only 1.19 million years (and not the 1.60 million years that Snelling claimed). If the identical rock had been formed 50 million years ago, the K-Ar would give a "false" age of a little over 51 million years. The rock sample to be dated must be chosen very carefully.
That is, a fresh mineral grain has its K-Ar "clock" set at zero.
The method relies on satisfying some important assumptions: Given careful work in the field and in the lab, these assumptions can be met.
The site also must be geologically meaningful, clearly related to fossil-bearing rocks or other features that need a good date to join the big story.
Lava flows that lie above and below rock beds with ancient human fossils are a good—and true—example.
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.
Thus this data is strongly supportive of mainstream geology.' [author's emphasis] As discussed at Ar-Ar Dating Assumes There is No Excess Argon? 49), the ONLY sample of the 26 that had significant excess argon also had very noticeable xenoliths (older rock contaminants that were incorporated into the magma as it rose through the Earth to the surface). Lanphere, 1969, Potassium-Argon Dating, Freeman, San Francisco.
Furthermore, as discussed in Funkhouser and Naughton (1968, p.
And in 25 times out of 26 tests there is no excess argon or there is so little excess argon that it will make only a tiny error, if any, in the final date for rocks millions of years old.
Thus Dalrymple’s data is not consistent with a young Earth whatsoever.
Potassium occurs in two stable isotopes (Ar atoms trapped inside minerals.