University Of Tasmania

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Zircon O and Lu-Hf isotope evidence of mantle and supracrustal origins of Tasmanian Devonian granites

journal contribution
posted on 2023-05-21, 13:18 authored by Jones, CL, Evan Orovan, Sebastien MeffreSebastien Meffre, Thompson, J, Belousova, EA, Matthew CracknellMatthew Cracknell, Everard, J, Bottrill, R, Bodorkos, S, David CookeDavid Cooke
The Tasmanian Devonian granites were emplaced during the Tabberabberan Orogeny when the East and West Tasmania Terranes were sutured. The primary aim of this study is to determine zircon O and Lu-Hf isotope constraints on, and relationships between, the magmas forming these granites. A second aim is to determine if these zircon isotopic compositions can be used to inform granite-related ore endowment. Several granites (n = 11 in East Tasmania Terrane, n = 1 West Tasmania Terrane) were previously dated by U-Pb geochronology using SHRIMP, and the zircon pits from the dating analyses were targeted firstly in O and later in Lu-Hf isotope analyses. The magmatic zircon ?18OVSMOW results ranged from mantle-like values (<5.7?) to values like supracrustal rocks (~12?). The granites with the lowest most mantle-like zircon ?18O are all I-types, and these include the relatively mafic Lisle to the very felsic and highly fractionated Mt Stronach and Tombstone Creek plutons. The Tombstone Creek zircon εHfi results are significantly lower than those of Lisle and Mt Stronach, indicating distinct melt sources from which the zircons crystallized. The magmatic zircon ?18O and εHfi results revealed two distinct paths of infracrustal to upper crustal rock εHfi- ?18O melt evolution: one "high ?Hf" path linking the results from the Lisle, Mt Stronach, Hazards, Henbury, Lottah, Gipps Creek and Royal George granites, and the other "low ?Hf" path linking those from Tombstone Creek, Meredith, Poimena, Bicheno and Ansons Bay granites. The paths are statistically different and modeled results are consistent with mixing of Mathinna Supergroup rocks with different isotopically defined infracrustal/mantle-like components. The high εHf group of granites are strongly associated with granite-related Au, Sn, and Sn-W ore deposits.


Australian Research Council

Alkane Exploration NL

AngloGold Ashanti Australia Limited

CMOC Mining Services Pty Ltd T/A Northparkes Mines

Department of Economic Development, Jobs, Transport and Resources

Department of State Growth (Tas)

Emmerson Resources Limited

Evolution Mining

Geological Survey of New South Wales - Department of Industry

Geoscience Australia

Heron Resources Limited

New South Resources Limited

Rio Tinto Limited

Sandfire Resoures NL


Publication title

Gondwana Research








School of Natural Sciences


Int Assoc Gondwana Research

Place of publication

Kochi Univ, Faculty Science Akebono-Cho 2-5-1, Kochi, Japan, 780-8520

Rights statement

© 2022 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Repository Status

  • Restricted

Socio-economic Objectives

Mineral exploration not elsewhere classified; Expanding knowledge in the earth sciences