(It would also be interesting to know if anyone has used it as a check on radiometric dating --- for example, since we know the date that Pompeii was buried, this provides a method for testing radiometric techniques.)
Exactly that has been done with potassium/argon (or argon/argon?) dating on ash from Pompeii - and they came out correct on the date. I have the paper at home, and can look up the citation if anyone wants it.