The zirconium stable isotope compositions of 22 geological reference materials, 4 zircons and 3 standard solutions

Abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Zirconium isotopic composition of the upper continental crust through time

“…The δ 94/90 Zr IPGP-Zr values we determined for BHVO-2 and GA are 0.048 ± 0.017‰ (2SD, n=4) and 0.13 ± 0.013‰ (2SD, n=7), respectively (Table S1), which agree well with data from the literature (Inglis et al, 2018;Tian et al, 2020a), confirming the accuracy of our data. Overall, the Zr isotope compositions of sedimentary rocks in this study are quite homogenous, ranging from 0.031 to 0.118‰ with an average δ 94/90 Zr IPGP-Zr of 0.078 ± 0.044‰ (2SD, n= 38), with a Zr-weighted average of 0.079 ± 0.044‰ (2SD, n=38).…”

“…Before chemical separation, the spiked solutions were heated at 120 ℃ for at least 12 hours to equilibrate the samples and double spike. Zirconium separation was achieved using a procedure described in Tian et al (2020a), which is modified after the approach reported in Inglis et al (2018). Because 4 M HF could not re-dissolve the samples completely, before loading on the first column, which is packed with 2 mL anion exchange resin (Bio-Rad AG1-X8 200-400 mesh), the sample solutions with precipitates were placed in an ultrasonic bath for h, then centrifuged.…”

“…Zirconium isotopic compositions were measured via the double spike method on a Thermo Fisher Neptune Plus MC-ICP-MS at IPGP. Measurement details are provided in Tian et al (2020aTian et al ( , 2020b Tian et al (2020a). Total procedure blanks were <1 ng for Zr.…”

Reliability of detrital marine sediments as proxy for continental crust composition: The effects of hydrodynamic sorting on Ti and Zr isotope systematics

“…Subsequent cooling at a sufficiently slow rate to maintain Zr isotope equilibrium in the residual melt during zircon growth can then account for the negligible bias in δ 94/90 Zr introduced by hydrodynamic sorting of zircon in the EMS sediments. Some support for this model is provided by the relatively unfractionated to slightly positive δ 94/90 Zr (0-0.1 ‰; Figure 7) of an unassorted set of rocks of broadly granitoid composition measured in several Zr isotope methodological studies (Inglis et al, 2018;Feng et al, 2020;Tian et al, 2020), which overlap with the regressed Saharan dust composition.…”

“…Millet and Dauphas, 2014;Millet et al, 2016;Greber et al, 2017;Deng et al, 2018;Deng et al, 2019;Aarons et al, 2020;Hoare et al, 2020). B) δ 94/90 Zr compared with literature data for basalts, granitoids (≥65 wt.% SiO 2 ) and sediments (Inglis et al, 2018;Inglis et al, 2019;Feng et al, 2020;Tian et al, 2020). Two Hekla rhyolites from Inglis et al (2019) at δ 94/90 Zr ca.…”