Detrital zircons in Triassic–Cretaceous sandstones, Clarence-Moreton Basin, eastern Australia: speculations upon Australia and Zealandia provenances

Abstract

Detrital zircon U–Pb age patterns in sandstones from the Triassic–Cretaceous Clarence-Moreton Basin, eastern New South Wales and Queensland, unexpectedly reveal sediment sources overwhelmingly dominated (>70%) by Precambrian–Cambrian zircons, with virtually no input, as was anticipated, from the nearby Carboniferous, Permian or Triassic magmatic arcs and contemporary accretionary wedge associated with the New England Orogen. Some rare, youngest zircons (<5%) are mostly contemporaneous with the estimated depositional age. The older, reworked zircon populations can only be acquired by postulating either (1) an Australian provenance by long overland sediment pathways from the interior to the west, during one or more transport cycles, perhaps from within the Thomson Orogen, and then bypassing or crossing the New England Orogen without any local contribution from that sector or (2) a North Zealandia provenance with a shorter transport distance from a postulated basement block to the east, within the Northern Lord Howe Rise and Kenn Plateau. This would comprise late Mesoproterozoic (1200–1000 Ma) and late Neoproterozoic–Cambrian (700–500 Ma) igneous and metamorphic complexes, similar to that proposed in South Zealandia.

KEY POINTS

1. Triassic to Jurassic Clarence-Moreton Basin sedimentary rocks have provenances unlike their hinterland time-correlates in New South Wales and Queensland.

2. The latter better share similarities with those in Murihiku Terrane, North Island, New Zealand.

3. The provenance of Clarence-Moreton sediments is similar to that of time-correlates in New Caledonia, and it is postulated that they share a source region on the northern Lord Howe Rise or Kenn Plateau.

Keywords:

• Clarence-Moreton Basin
• New England Orogen
• U–Pb detrital zircon ages
• sediment provenance

Acknowledgements

Norman Pearson, Will Powell and Yi-Jen Li are thanked for their technical assistance at the GEMOC and CCFS analytical facilities, in the Department of Earth and Environmental Sciences, Macquarie University, Sydney. Nick Mortimer, Belinda Smith Lyttle and Luke Easterbrook-Clarke (GNS Science, Dunedin Office) are thanked for their support with figures.

Disclosure statement

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

Data availability statement

The data that support the findings of this study are openly available in Figshare at https://doi.org/10.6084/m9.figshare.19352519.

Additional information

Funding

Fieldwork (CJA and HJC) associated with this research and acquisition of analytical data (CJA) were undertaken in the early 2000s as part of a GNS Science project funded by the New Zealand Foundation for Research Science and Technology. It has been completed without funding. As Emeritus scientists, we thank GNS Science (CJA and HJC), Geoscience Australia (RJK) and Macquarie University (WLG) for ongoing support.