Concordia-discordia diagram

Figure 11,26 Concordia diagram. (A) Interpretation of straight discordia path as a result of a single episode of Pb loss. (B) Continuous diffusion model of Tilton (1960) applied to world minerals of a = 2800 Ma common age. Reproduced with modifications from G. Faure (1986), Principles of Isotope Geology, 2nd edition, copyright 1986 by John Wiley and Sons, by permission of John Wiley Sons and from Tilton (1960) by permission of the American Geophysical Union.

Tera-Wasserburg diagram for lunar basalt 14053. The measured data define a discordia line that intersects the -axis at (207 /206 ), = 1.46. The slope of the line, based on two whole-rock samples and a magnetite separate, is -0.88366. The intersection of the discordia line with the concordia curve gives the age of the sample. After Faure and Mensing (2005). 

Fig. 10. Concordia diagram showing monazite and zircon relations. Discordia line intersecting concordia at 1,930 m.y. is from Catanzaro and Kulp (1964), Little Belt Mountains, Montana The discordia line intersecting concordia at 2,900 m.y. is from Heimlich and Banks (1968), Bighorn Mountains, Wyoming. Crosses are plottings for zircons boxes are plottings for monazites...

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