Penglai Zircon Megacrysts: A Potential New Working Reference Material for Microbeam Determination of Hf–O Isotopes and U–Pb Age

We introduce a potential new working reference material – natural zircon megacrysts from an Early Pliocene alkaline basalt (from Penglai, northern Hainan Island, southern China) – for the microbeam determination of O and Hf isotopes, and U–Pb age dating. The Penglai zircon megacrysts were found to be fairly homogeneous in Hf and O isotopes based on large numbers of measurements by LA‐multiple collector (MC)‐ICP‐MS and SIMS, respectively. Precise determinations of O isotopes by isotope ratio mass spectrometry (IRMS) and Hf isotopes by solution MC‐ICP‐MS were in good agreement with the statistical mean of microbeam measurements. The mean δ 18 O value of 5.31 ± 0.10‰ (2 s ) by IRMS and the mean 176 Hf/ 177 Hf…