TY - JOUR

T1 - Novel Methods for Concomitant Determination of the Stable Zr Isotope Composition, Lu-Hf Isotope Systematics and U-Pb Age of Individual Zircons

AU - Jensen, Ninna K.

AU - Deng, Zhengbin

AU - Connelly, James N.

AU - Bizzarro, Martin

N1 - Publisher Copyright: © 2023 The Authors. Geostandards and Geoanalytical Research published by John Wiley & Sons Ltd on behalf of International Association of Geoanalysts.

PY - 2024

Y1 - 2024

N2 - The stable Zr isotope ratios in zircon yield a novel geochemical tracer that, together with the Lu-Hf and U-Pb radiogenic isotope systems, allows for a better understanding of the magmatic evolution of silicate melts. We present a solution-based procedure for coupled stable Zr, Lu-Hf and U-Pb isotope ratio determinations for individual zircons using a 91Zr-96Zr tracer purified from Hf and a late-spiking protocol for Zr. This method yields high-precision Zr and Hf isotope results while maintaining low blank levels for U-Pb isotope and Lu/Hf ratio determinations. With a two-fold improvement on the precision relative to previous solution-based work, we report δ94ZrIPGP-Zr values (deviation of the 94Zr/90Zr ratio in the sample relative to the IPGP-Zr reference material) and associated intermediate precisions (2s) for the zircon reference materials 91500, Mud Tank, Plešovice and Penglai of -0.041 ± 0.015‰, 0.018 ± 0.013‰, 0.089 ± 0.020‰ and -0.117 ± 0.021‰, respectively. Furthermore, this method yields un-biased δ94ZrIPGP-Zr and 176Hf/177Hf results for 25-ng Zr and 0.56-ng Hf aliquots of the Mud Tank zircon with intermediate precisions (2s) of 0.027‰ and 1.7 ε (parts per ten thousand), respectively. Thus, the presented method is applicable for the analysis of extremely small and rare zircon grains.

AB - The stable Zr isotope ratios in zircon yield a novel geochemical tracer that, together with the Lu-Hf and U-Pb radiogenic isotope systems, allows for a better understanding of the magmatic evolution of silicate melts. We present a solution-based procedure for coupled stable Zr, Lu-Hf and U-Pb isotope ratio determinations for individual zircons using a 91Zr-96Zr tracer purified from Hf and a late-spiking protocol for Zr. This method yields high-precision Zr and Hf isotope results while maintaining low blank levels for U-Pb isotope and Lu/Hf ratio determinations. With a two-fold improvement on the precision relative to previous solution-based work, we report δ94ZrIPGP-Zr values (deviation of the 94Zr/90Zr ratio in the sample relative to the IPGP-Zr reference material) and associated intermediate precisions (2s) for the zircon reference materials 91500, Mud Tank, Plešovice and Penglai of -0.041 ± 0.015‰, 0.018 ± 0.013‰, 0.089 ± 0.020‰ and -0.117 ± 0.021‰, respectively. Furthermore, this method yields un-biased δ94ZrIPGP-Zr and 176Hf/177Hf results for 25-ng Zr and 0.56-ng Hf aliquots of the Mud Tank zircon with intermediate precisions (2s) of 0.027‰ and 1.7 ε (parts per ten thousand), respectively. Thus, the presented method is applicable for the analysis of extremely small and rare zircon grains.

KW - Hf isotopes

KW - MC-ICP-MS

KW - stable Zr isotopes

KW - zircon reference material

KW - Zr double spike

U2 - 10.1111/ggr.12529

DO - 10.1111/ggr.12529

M3 - Journal article

AN - SCOPUS:85174181201

VL - 48

SP - 5

EP - 28

JO - Geostandards and Geoanalytical Research

JF - Geostandards and Geoanalytical Research

SN - 1639-4488

IS - 1

ER -