Strangely enough, when NASA scientists took a look at the amount of dust falling into the Earth's atmosphere from space, they very accurately predicted the amount that is on the moon. Not much.
It has nothing to do with this. Its half-life is so short that it can't be used for things that are more than about 50,000 years old. However, it has been calibrated by using lake varves of testable age, and the calibration curve is pretty close to what we had before that was possible. Would you like to see?