Radiometric dating of moon rocks
It is rare for a study involving radiometric dating to contain a single determination of age.
Usually determinations of age are repeated to avoid laboratory errors, are obtained on more than one rock unit or more than one mineral from a rock unit in order to provide a cross-check, or are evaluated using other geologic information that can be used to test and corroborate the radiometric ages.
Even things that work well do not work well all of the time and under all circumstances.
Try, for example, wearing a watch that is not waterproof while swimming. A few verified examples of incorrect radiometric ages are simply insufficient to prove that radiometric dating is invalid.
Creationists seem to think that a few examples of incorrect radiometric ages invalidate all of the results of radiometric dating, but such a conclusion is illogical.
Only rarely does a creationist actually find an incorrect radiometric result (Austin 1996; Rugg and Austin 1998) that has not already been revealed and discussed in the scientific literature.
The creationist approach of focusing on examples where radiometric dating yields incorrect results is a curious one for two reasons.
The heat of the impact melted some of the feldspar crystals in the granitic rocks of the impact zone, thereby resetting their internal radiometric clocks.
These melted crystals, and therefore the impact, have been dated by the 40Ar/39Ar method at 74.1 Ma (million years; Izett and others 1998), but that is not the whole story by a long shot.Scientists who use radiometric dating typically use every means at their disposal to check, recheck, and verify their results, and the more important the results the more they are apt to be checked and rechecked by others.