Uranium series dating jewish interatial dating
The straight line takes the zircons off the concordia. The disturbing event affects the zircons unequally, stripping all the lead from some, only part of it from others and leaving some untouched.The results from these zircons therefore plot along that straight line, establishing what is called a discordia. If a 1500-million-year-old rock is disturbed to create a discordia, then is undisturbed for another billion years, the whole discordia line will migrate along the curve of the concordia, always pointing to the age of the disturbance.Other minerals sometimes used for uranium-lead dating include monazite, titanite and two other zirconium minerals, baddeleyite and zirconolite.
If nothing disturbs the grain to release any of this radiogenic lead, dating it is straightforward in concept.
With 238U the Pb/U ratio grows much more slowly with age, but the idea is the same.