However, zircon is so overwhelming a favorite that geologists often just refer to "zircon dating."But even the best geologic methods are imperfect.
If nothing disturbs the grain to release any of this radiogenic lead, dating it is straightforward in concept.Of all the isotopic dating methods in use today, the uranium-lead method is the oldest and, when done carefully, the most reliable.Unlike any other method, uranium-lead has a natural cross-check built into it that shows when nature has tampered with the evidence.Some zircons are obviously disturbed and can be ignored, while other cases are harder to judge.
In these cases, the concordia diagram is a valuable tool.
That would take the zircons on a straight line back to zero on the concordia diagram.