eCite Digital Repository

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

Citation

Jones, CL and Orovan, EA and Meffre, S and Thompson, J and Belousova, EA and Cracknell, MJ and Everard, J and Bottrill, R and Bodorkos, S and Cooke, DR, Zircon O and Lu-Hf isotope evidence of mantle and supracrustal origins of Tasmanian Devonian granites, Gondwana Research, 110 pp. 1-12. ISSN 1342-937X (2022) [Refereed Article]

Copyright Statement

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

DOI: doi:10.1016/j.gr.2022.06.004

Abstract

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.

Item Details

Item Type:Refereed Article
Keywords:zircons; Tasmania; Devonian; granite;zircon; O-isotope; Hf-isotope; melt evolution;mineralization
Research Division:Earth Sciences
Research Group:Geology
Research Field:Geochronology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:Jones, CL (Mr Colin Jones)
UTAS Author:Orovan, EA (Mr Evan Orovan)
UTAS Author:Meffre, S (Professor Sebastien Meffre)
UTAS Author:Thompson, J (Mr James Thompson)
UTAS Author:Cracknell, MJ (Dr Matthew Cracknell)
UTAS Author:Cooke, DR (Professor David Cooke)
ID Code:153033
Year Published:2022
Funding Support:Australian Research Council (LP160100483)
Deposited By:CODES ARC
Deposited On:2022-09-01
Last Modified:2022-10-05
Downloads:0

Repository Staff Only: item control page