The Papuan Orogen: A Misplaced Mesozoic Belt of the Tasman Orogenic Zone

Authors: Robert Holm, Dulcie Saroa, Lloyd White and Kelly Heilbronn

PAPUA NEW GUINEA

GEOSCIENCE NETWORKMineralResourcesAuthor i t y

Long-lived, overall convergent margin from the Cambrian

through to the Triassic, succeeded by Cretaceous break-up.

What happened during the late Triassic to Lower Cretaceous

in eastern Australia? Where are the rocks?

Permian to Cretaceous rocks have been found submerged to

the east of Australia – is this it?

The Tasman Orogenic Zone

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How about Papua New Guinea?

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Port Moresby

What does this have to do with the Tasman Orogenic Zone?

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Zircon morphology indicates zircons are detrital and Cretaceous (ca. 100 Ma) depositional age matches the basement Owen Stanley Metamorphics.

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Carboniferous-Permian sources are prevalent in

contemporaneous basins but are under-represented

in regional Jurassic and Cretaceous detritus.

Carboniferous-Early Triassic sources are not being

recycled on a regional-scale, are they concealed

beneath cover?

Older basement sources still contribute to detritus

and can be used to trace provenance signatures.

Consider the Regional Jurassic and Cretaceous Basins

Current Reconstructions?

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Alternate Provenance

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Provence-Based Reconstruction

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The New Guinea Mobile Belt?

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The New Guinea Mobile Belt?

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The Bird’s Head – West Papua?

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Webb et al., 2019

The Bird’s Head – West Papua?

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Mesozoic Rocks of New Guinea

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Evidence for a long-lived convergent margin east of

Australia throughout the late Mesozoic.

A new late Mesozoic orogen is required within the Tasman

Orogenic Zone – the Papuan Orogen…

Conclusions and Implications

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