GHR1 Zircon - A New Eocene Natural Reference Material for Microbeam U-Pb Geochronology and Hf Isotopic Analysis of Zircon - Eddy, Michael; Ibañez-Mejia, Mauricio; Burgess, Seth D.; Coble, Matthew A.; Cordani, Umberto G.; DesOrmeau, Joel; Gehrels, George; Li, Xianhua; MacLennan, Scott; Pecha, Mark; Sato, Kei; Schoene, Blair; et al. (Geostandards and Geoanalytical Research, 2019)