The common phosphate minerals, apatite Ca5(PO4)3(F,OH,Cl), monazite (Ce,La,Th)PO4, and xenotime YPO4, have found widespread use in geochronology because they incorporate U and Th into their structures. For example, apatite usually has a few tens of ppm of both U and Th, while monazite and xenotime usually have hundreds of ppm to weight percent levels of these elements. As a consequence, these phosphates can be dated using several fundamentally different isotopic techniques. Elsewhere in this volume Harrison et al. describe phosphate dating using ingrowth of radiogenic Pb, the final daughter of...

First Page Preview

First page PDF preview
You do not currently have access to this article.