Silicon isotope measurement in zircon by laser ablation multiple collector inductively coupled plasma mass spectrometry

This study reports the first Si isotope data measured in zircon using nanosecond laser ablation multiple collector inductively coupled plasma mass spectrometry. Long-term (>2 years) external reproducibility obtained on the 91500 zircon standard is 0.13 parts per thousand and 0.21 parts per thousand (2SD) for delta Si-29 and delta Si-30 (per mil deviation from the quartz reference NBS 28), respectively, and typical precision on a single run is on the order of 0.10 parts per thousand and 0.12 parts per thousand (2SE) for delta Si-29 and delta Si-30, respectively. Our results show good consistency between laser ablation multiple collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) and solution multiple collector inductively coupled plasma mass spectrometry (S-MC-ICP-MS)/secondary ionization mass spectrometry (SIMS) data demonstrating that the Si isotopic composition of zircon can be accurately measured by LA-MC-ICP-MS. Obtained delta Si-30 values on natural zircon standards range from -0.32 +/- 0.23 parts per thousand (2SD) for 91500 to -0.47 +/- 0.17 parts per thousand for MudTank, whereas the MUN (synthetic) zircon standards have lower delta Si-30 values around -2.0 parts per thousand (e.g.-2.08 +/- 0.17 parts per thousand for MUN-1-2b). Silicon isotope measurements by LA-MC-ICP-MS open new possibilities for studying zircon formation in various geological contexts.