(U-Th)/He Dating: Techniques, Calibrations, and Applications

The possibility of dating minerals by the accumulation of ^4He from U and Th decay
\nhas been recognized for many years (e.g., Strutt 1905), but in the century since the idea
\nwas first conceived, the method has rarely been applied successfully. After several
\ninvestigations of (U-Th)/He dating of various minerals (e.g., Damon and Kulp 1957;
\nFanale and Kulp 1962; Damon and Green 1963; Turekian et al. 1970; Bender 1973;
\nLeventhal 1975; Ferreira et al. 1975) the technique was essentially abandoned as yielding
\nunreliable and usually low ages, presumably as a result of diffusive He loss possibly
\nassociated with radiation damage. In 1987, Zeitler and coworkers rekindled…