Eggins, StephenGrun, RainerPike, Alistair W GShelley, MichaelTaylor, Lois2015-12-132015-12-130277-3791http://hdl.handle.net/1885/76189U and Th concentration profiles in fossil hominid and faunal teeth have been measured by laser ablation ICPMS. These profiles record diverse modes of U and Th uptake, particularly within enamel, that can be broadly related to the state of sample preservation. Observed U profiles are in general inconsistent with existing diffusion-adsorption models developed for U-uptake in bone and teeth. Where the models appear applicable, calculated diffusion rates are several orders of magnitude smaller than previous estimates. Laser ablation ICPMS offers a means of rapidly characterizing U and Th distributions in the enamel and dentine components of teeth as a precursor to ESR and U-series dating. In particular, it should allow the identification of teeth (and also bone) samples that have simple U-uptake histories and are amenable to precise dating by time-consuming and expensive Th-U and Pa-U TIMS techniques. We also demonstrated the use of laser ablation ICPMS to measure U-series isotopes in dentine and enamel samples with relatively high U concentrations (> 20 ppm). These results, obtained using a quadrupole ICPMS, illustrate significant promise for in situ U-series isotope analysis, particularly when combined with the greater sensitivity and multi-collection capabilities of new sector ICPMS instrumentation. The latter may permit precise isotope ratio measurements on samples containing only a few ppm of U.Keywords: Diffusion; Enamels; Geochronology; Inductively coupled plasma; Laser ablation; Mass spectrometry; Faunal teeth; Radioisotopes; biological uptake; conference proceeding; dating method; enamel; geochronology; inductively coupled plasma method; tooth; uraniu200310.1016/S0277-3791(03)00064-72015-12-11