I am reading studies about the age of the earth and U-238 to Pb-206 comes up a lot.
My question is:
In meteorites, or really anywhere, is lead 206 natural or does it always come from radioactive decay?
If it is natural is the potential quantity of that daughter isotope capable of skewing the results and predicted age? So if there was already some of that isotope there it would seem as if it had been decaying for longer and therefore thought to be older?