concordia diagram

plural concordia diagrams

1. geographyAny of several types of diagram, used in connection with uranium–lead dating, in which each axis encodes differently sourced information about the radiometric age of the mineral being dated.

   Concordia diagrams are the most common way to present U-Pb data in the modern literature, so understanding them is key to understanding the method.

   2018, Peter W. Reiners, Richard W. Carlson, Paul R. Renne, Kari M. Cooper, Darryl E. Granger, Noah M. McLean, Blair Schoene, Geochronology and Thermochronology, Wiley, page 177

   2 more examples

   The graphing of concordant U-Pb data on a concordia diagram does not provide any information that is not obvious from the individual U-Pb ages themselves. The principal value of the concordia diagram is its unique ability to yield crystallization ages from open systems.

   1991, G. Brent Dalrymple, The Age of the Earth, Stanford University Press, page 117

   A concordia diagram is simply a plot of ^{₂₀₆}Pb^{\ast}/^{₂₃₈}U versus ^{₂₀₇}Pb^{\ast}/^{₂₃₅}U; that is, the number of atoms of radiogenic daughter produced to the number of atoms of radioactive parent. You should satisfy yourself that both of these ratios are proportional to time. In essence, the concordia diagram is a plot of the ^{₂₃₈}U-\!^{₂₀₆}Pb age against the ^{₂₃₅}U-\!^{₂₀₇}Pb age. The concordia curve on such a diagram[…]is the locus of points where the ^{₂₃₈}U-\!^{₂₀₆}Pb age equals the ^{₂₃₅}U-\!^{₂₀₇}Pb age. Such ages are said to be concordant.

   2015, William M. White, Isotope Geochemistry, Wiley, page 78