Wetherill diagram

The "x" and "y" axes of the Wetherill diagram are the quantities of the respective end (lead) isotopes of the actinium series and uranium series decay chains, each adjusted and expressed as a ratio to the amount remaining of the corresponding start (uranium) isotope.

In the Wetherill diagram, no isotope is found on both axes, allowing the two decay schemes to be evaluated independently.

2020, Myint Myat Phyo, et al., U—Pb Dating of Zircon and Zirconolite Inclusions in Marble-Hosted Gem-Quality Ruby and Spinel from Mogok, Myanmar, Frederick Lin Sutherland, Khin Zaw (editors), Mineralogy and Geochemistry of Ruby, MDPI Books, page 115, Figure 4. Wetherill diagrams showing wide range of U-Pb age of (a) zircon inclusion in gem-quality ruby and spinel, (b) accessory zircon in Bawlongyi marble, (c) zirconolite inclusion in ruby from Mansin and (d) zirconolite intergrown with zircon in Bawlongyi marble.