Allanite dating

Mineral inclusions. In our experience at Caltech the single biggest difficulty in He dating of apatite is the presence of small U-Th-rich inclusions within the dated grains. This difficulty was first noted by Lippolt et al. (1994) and was further described by House et al. (1997). The most common inclusions are zircon and monazite, but we have occasionally encountered xenotime and allanite. We have also observed inclusions of quartz, feldspar, pyrite and graphite( ), but these are unlikely to carry sufficient U and Th to be a problem. 

Apart from zircon, other common accessory minerals that can be used for U/Th-Pb dating are monazite, rutile, titanite, apatite and allanite results on rarer minerals such as columbite-tantalite, perovskite, baddeleyite and the uranium ore minerals uraninite and davidite have also been reported. 

J. (2003) Laser-ablation U/Th-Pb in situ dating of zircon and allanite an example from the October Harbour granite, central coastal Labrador, Canada. Can. Mineral, 41, 273-291. 

Epidote proper has received little attention for U-Th-Pb dating, but some data which suggest that it should be investigated further have been published (Narbutt et al, 1959 Mineev, 1959). Considerable work, however, has been done on allanite (the cerium-bearing member). The first analysis was reported by Vinogradov et al (1952), and the... 

---