Radioactive dating works best with what type of rocks
He didn't pretend that the age of the flows was the expected result, and he didn't make the false claim that his result was sufficient to call all isochron dating into question.This is a transparent attempt to place a GSA "seal of approval" on Austin's unsupportable The length of the medium is not a legitimate excuse for a blatant falsehood (the claim that Austin set out to "test" Rb/Sr dating) or for the shenanigans involving the sampling technique versus the expected meaning of the resulting age.Even young-earth creationists would agree with this relative sequencing of events.They would argue for a much shorter absolute timescale than mainstream geologists would accept, but the relative sequence is agreed upon by all parties. Steven Austin, chairman of the Geology Department at the Institute for Creation Research, claimed (1992) that he had derived an isochron for the plateau flows, which indicates an age of about 1.3 billion years.One particular Precambrian layer known as the Cardenas Basalt has been dated by radiometric methods to about 1.1 billion years in age.The Cenozoic flows sampled by ICR thus are claimed to yield an age which is about 200 million years older than the Cardenas Basalt.If it is not the flows' age, that is not a "problem" with isochron dating, and it is not relevant to the large number of Rb/Sr isochrons which were computed from mineral separations of a single object.
Austin was aware of this, as his 1988 reference to Faure shows. Unfortunately, it was submitted anonymously and it didn't address the key issues above.
As discussed above, whole-rock samples of multiple flows yields the time since their common source was isotopically homogeneous.
It also be the age of the flows, but it does not have to be.
A variety of analytical instruments have also now been developed using different micro-sampling techniques coupled with mass spectrometers, thus enabling wide usage of U-Pb radioisotope dating.
However, problems remain in the interpretation of the measured Pb isotopic ratios to transform them into ages.