Detrital zircon provenance of Permian to Triassic Gondwana sequences, Zealandia and eastern Australia

ABSTRACT

Permian Parapara Group and Triassic Topfer Formation are small clastic sedimentary outliers that rest on Cambrian to Devonian basement terranes in the Western Province of South Island, New Zealand. New detrital zircon U-Pb age datasets from three Parapara sandstones, one Topfer sandstone and four age-equivalent eastern Australian sandstones reveal age and provenance information about former Gondwana intracontinental basins. Youngest significant zircon age populations of 264 ± 6 and 261 ± 2 Ma in two Parapara Group sandstones and 215 ± 2 Ma in the Topfer sandstone match fossil ages and indicate broadly syn-depositional igneous activity. The provenance of the igneous detritus was probably the nearby Median Batholith and/or its volcanic equivalents. Zircons in a third Parapara sandstone are predominantly Cambrian and Precambrian in age and represent a separate petrofacies with a local Western Province basement terrane provenance. Intra-basin provenance switching between Gondwana margin arc and older basement sources is thus documented in Gondwana basin sequences in Zealandia, as well as those in Australia and Antarctica.

KEYWORDS:

• New Zealand
• Australia
• Gondwana
• Permian
• Triassic
• detrital zircon U-Pb ages
• tectonics

Acknowledgements

Norman Pearson, Will Powell and Yi-Jen Lai are thanked for their technical assistance at Macquarie University, Sydney. Earlier versions of the manuscript were improved by comments from Kevin Faure, John Goodge, Jonathan Aitchison and an anonymous reviewer. The authors thank Richard Wysoczanski for supplying data tables from his earlier study of Parapara Group zircons. This is contribution 1670 from the ARC Centre of Excellence for Core to Crust Fluid Systems (www.ccfs.mq.edu.au) and 1470 from the GEMOC Key Centre (www.gemoc.mq.edu.au).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Supplemental Data Files SF1 and SF2 are available in the Figshare online repository at https://doi.org/10.6084/m9.figshare.14889078.

Additional information

Funding

The work was made possible by core funding to GNS Science from the Ministry of Business Innovation and Employment and its predecessors. This study used instrumentation funded by ARC LIEF and DEST Systemic Infrastructure Grants, Macquarie University and industry.