LKZ-1: A New Zircon Working Standard for the In Situ Determination of U–Pb Age, O–Hf Isotopes, and Trace Element Composition

This study introduces a new zircon reference material, LKZ-1, for the in situ U&ndash
Pb dating and O&ndash
Hf isotopic and trace element analyses. The secondary ion mass spectrometric analyses for this gem-quality single-crystal zircon yielded a weighted mean 206Pb/238U age of 572.6 &plusmn
2.0 Ma (2&sigma
n = 22, MSWD = 0.90), with moderately high U concentrations (619 &plusmn
21 ppm, 1 SD), restricted Th/U ratios (0.146 &plusmn
0.002, 1 SD), and negligible common Pb content (206Pbc &lt
0.2%). A comparable 206Pb/238U age (570.0 &plusmn
2.5 Ma, 2&sigma
) was produced by the isotope dilution-thermal ionization mass spectrometry. The secondary ion mass spectrometric and laser ablation-assisted multiple collector inductively coupled plasma mass spectrometer analyses respectively showed that LKZ-1 had little variation in O (&delta
18OV-SMOW = 10.65 &plusmn
0.14&permil
laser fluorination value = 10.72 &plusmn
0.02&permil
1 SD) and Hf (176Hf/177Hf = 0.281794 &plusmn
0.000016, 1 SD) isotopic compositions. LKZ-1 was also fairly homogeneous in its chemical composition (RSD of laser ablation ICPMS data &le
10%), displaying a relatively uniform chondrite-normalized rare earth element pattern ((Lu/Gd)N = 31 &plusmn
3, Eu/Eu* = 0.43 &plusmn
0.17, Ce/Ce* = 44 &plusmn
32
1 SD). These consistencies suggest that the LKZ-1 zircon is a suitable working standard for geochronological and geochemical analyses.