Further Characterization of the BB Zircon via SIMS and MC-ICP-MS for Li, O, and Hf Isotopic Compositions

In this contribution, we report the results for the characterization of the BB zircon, a newly developed zircon reference material from Sri Lanka, via secondary ion mass spectrometry (SIMS) and multiple-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). The focus of this work was to further investigate the applicability of the BB zircon as a reference material for micro-beam analysis, including Li, O, and Hf isotopes. The SIMS analyses reveal that BB zircon is characterized by significant localized variations in Li concentration and isotopic ratio, which makes it unsuitable as a lithium isotope reference material. The SIMS-determined delta O-18 values are 13.81 parts per thousand +/- 0.39 parts per thousand (2SD, BB16) and 13.61 parts per thousand +/- 0.40 parts per thousand (2SD, BB40), which, combined with previous studies, indicates that there is no evidence of conspicuous O isotope heterogeneity within individual BB zircon megacrysts. The mean Hf-176/Hf-177 ratio of BB16 determined by solution MC-ICP-MS is 0.281669 +/- 0.000012 (2SD, n = 29) indistinguishable from results achieved by laser ablation (LA)-MC-ICP-MS. Based on the SIMS and MC-ICP-MS data, BB zircon is proposed as a reference material for the O isotope and Hf isotope determination.