Trace Element Characterisation of MAD‐559 Zircon Reference Material for Ion Microprobe Analysis

Abstract

We document the composition of a natural zircon gemstone sourced from Madagascar, MAD‐559 – a new reference material for calibrating trace element mass fractions in zircon measured by SIMS. The composition of MAD‐559 was quantified by calibration relative to the well‐documented zircon reference material 91500, for which we compiled existing published data (Mg, Al, Y, rare earth elements, Hf, U, Th) and performed new measurements to characterise the mass fraction of less commonly measured elements (Li, Be, B, F, Na, P, K, Ca, Sc, Ti, Fe, Nb). Measurement results of SL13, CZ3 and MAD‐1 zircons and NIST SRM glasses were performed as quality control materials to test measurement bias and repeatability. We show the intermediate precision for most trace element measurement results of MAD‐559 to be between ± 3% and ± 5% RSD based on 139 measurements by SIMS on twenty‐five individual polished zircon chips measured during a 24‐h period, as well as repeat measurements performed over five separate analytical sessions. Trace element mass fractions were also measured by LA‐ICP‐MS in two different laboratories, and major element compositions measured by electron microprobe, to compare with results measured by SIMS. Based on laser Raman and hyperspectral cathodoluminescence spectroscopy, we show MAD‐559 to have high crystal disorder due to radiation damage relative to crystalline zircon (e.g., SL13 and 91500 zircon). Although the high cumulative alpha dose of MAD‐559 zircon makes it a poor reference material for geochronology, the consistency of the trace element mass fraction results measured in multiple sessions and by various measurement methods shows that it is an ideal reference material for microanalytical trace element mass fraction quantification of zircon.

Repeated Rhyolite Eruption From Heterogeneous Hot Zones Embedded Within a Cool, Shallow Magma Reservoir

“…We calculated a mean of 5.1 ± 0.5 (1 σ ) from the LdM zircon rim measurements, the uncertainty of which is propagated onto the analytical uncertainty of each zircon date. Supporting information S1 contains additional details of the analytical conditions and date calculations (Barth & Wooden, ; Coble et al, ; Szymanowski et al, ).…”

“…We calculated a mean K U=Th zrc−melt of 5.1 ± 0.5 (1σ) from the LdM zircon rim measurements, the uncertainty of which is propagated onto the analytical uncertainty of each zircon date. Supporting information S1 contains additional details of the analytical conditions and date calculations (Barth & Wooden, 2010;Coble et al, 2018;Szymanowski et al, 2018). tainties; ages constrained by field relationships are illustrated by gray fields without a line Fierstein, 2018;Hildreth et al, 2010).…”

Temporal and spatial variations in magmatism and transpression in a Cretaceous arc, Median Batholith, Fiordland, New Zealand

“…Twenty-two samples in four different epoxy mounts were analyzed for zircon U-Pb isotopes, as well as trace elements (Ti, Fe, Y, 9 rare earth elements [REEs], Hf, U, Th), following methods described by Coble et al (2018). Depending on the abundance from mineral separates, between 60 and 100 zircons were picked and mounted per sample.…”

The timing of migmatization in the northern Arabian–Nubian Shield: Evidence for a juvenile sedimentary component in collision‐related batholiths

“…The primary ion beam spot had a diameter between 22 and 28 μm and a depth of~1-2 μm for the analyses performed in this study. Before every analysis, the sample surface was cleaned by rastering the primary beam for 60-120 s. Trace element analyses were performed with a mass resolution of 6,800-7,200 (10% peak height), and concentrations (Y, Hf, REE) were standardized relative to MAD-559 zircon follow the methods described by Coble et al (2018). Data reduction for zircon geochronology follows the methods described by Williams (1998), and Ireland and Williams (2003), and uses the MS Excel add-in programs Squid 2.51 and Isoplot 4 of Ludwig (2012).…”