on 05-11-201704:40 AM - edited on 11-09-202104:13 AM by usermigration2
1) Laboratorio de Estudios Isotópicos, Centro de Geociencias, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro 76230, Mexico, 2) Departamento de Geoquímica, Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City 04510, Mexico, 3) Centro de Investigación y de Estudios Avanzados, Unidad Querétaro, Libramiento Norponiente #2000, 76230 Querétaro, Mexico Quaternary Geochronology (2014), V23, pp46–55, doi: 10.1016/j.quageo.2014.06.003 In-situ 230Th/U dating of Quaternary zircons using LA-MCICPMS J.P. Bernal (1), L.A. Solari (1), A. Gómez-Tuena (1), C. Ortega-Obregón (1), L. Mori (2), M. Vega-González (1), D.G. Espinosa-Arbeláez (3) Zircon is the most widely used mineral for geochronology purposes, as parts of it can behave as a closed system for billions of years and resist most geochemical alteration; yet, its use in Quaternary geochronology has been largely overseen, and limited to few laboratories. Here we present a new simple methodology to obtain precise and accurate 238U–230Th–232Th composition from zircons using LA-MCICPMS, which permits obtaining meaningful ages of well constrained Pleistocene and Holocene volcanic samples from Mexico. The results are compared with that of alternative instrumental techniques, such as SIMS, and other radiogenic dating methods (40Ar/39Ar, 36Cl and 14C). Our results show that the technique presented here is superior to SIMS in terms of precision, and analysis time, and equivalent in terms of sensitivity and spatial resolution.