It is well known that radioactive decay of 235U, 238U, and 232Th to their ultimate stable daughter products (207Pb, 206Pb, and 208Pb, respectively) is widely used in dating geological materials. It is also generally recognized that these parent/daughter systems are suitable only for dating very old samples, because the parent isotopes have geologically long half-lives (that of 235U is shortest at 0.7 Gyr).1

...
Less widely appreciated is the fact that the U,Th→Pb systems can be used for dating much younger events by measuring intermediate decay products. All three decay series involve...

First Page Preview

First page PDF preview
You do not currently have access to this article.