A revised Proterozoic tectono-stratigraphy of the South Nicholson region, Northern Territory, Australia — insights from SHRIMP U-Pb detrital zircon geochronology

Authors / CoAuthors

Carson, C. | Kositcin, N. | Anderson, J. | Henson, P.

Abstract

<div>New SHRIMP U-Pb detrital zircon geochronology on Mesoproterozoic and Paleoproterozoic siliciclastic rocks from the South Nicholson region, in concert with recently acquired complementary regional geophysical datasets, has enabled comprehensive revision of the regional Proterozoic tectono-stratigraphy. The identification of analogous detrital zircon spectra between units deposited in half-graben hanging walls of major ENE-WSW trending extensional faults, the Benmara, Bauhinia, and Maloney-Mitchiebo faults, offers compelling evidence for regional tectono-stratigraphic correlation. Units sampled from the hanging walls of these faults are characterised by immature proximal lithofacies and host a small yet persistent population of <em>ca</em> 1640–1650 Ma aged zircon and lack Mesoproterozoic detritus, consistent with deposition coincident with extension during the River Extension event at <em>ca</em> 1640 Ma, an event previously identified from the Lawn Hill Platform in western Queensland. This finding suggests the hanging wall sequences are chrono-stratigraphically equivalent to the highly prospective sedimentary rocks of the Isa Superbasin, host to world-class sediment-hosted base metal deposits across western Queensland and north-eastern Northern Territory. Subsequent inversion of the extensional faults, resulted in development of south-verging thrusts, and exhumation of late Paleoproterozoic hanging wall siliciclastic rocks through overlying Mesoproterozoic South Nicholson Group rocks as fault propagated roll-over anticlines. These geochronology data and interpretations necessitate revision of the stratigraphy and the renaming of a number of stratigraphic units in the South Nicholson region. Accordingly, the distribution of the highly prospective late Paleoproterozoic units of the McArthur Basin, Lawn Hill Platform and Mount Isa Province is greatly expanded across the South Nicholson region. These findings imply that the previously underexplored South Nicholson region is a highly prospective greenfield for energy and mineral resources.</div> <b>Citation:</b> C. J. Carson, N. Kositcin, J. R. Anderson & P. A. Henson (2023) A revised Proterozoic tectono-stratigraphy of the South Nicholson region, Northern Territory, Australia—insights from SHRIMP U–Pb detrital zircon geochronology, <i>Australian Journal of Earth Sciences,</i> DOI: 10.1080/08120099.2023.2264355

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document

eCat Id

147696

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Commonwealth of Australia (Geoscience Australia)
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Keywords

( Project )

Barkly-Isa-Georgetown

( Project )

EFTF – Exploring for the Future

SHRIMP

U-Pb geochronology

Stratigraphy

South Nicholson region

Northern Territory

Prospectivity

Published_External

theme.ANZRC Fields of Research.rdf

Stratigraphy (incl. biostratigraphysequence stratigraphy and basin analysis)GeochronologyStructural geology and tectonics

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2023-02-16T06:00:00

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Australian Government Security Classification System

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Creative Commons Attribution 4.0 International Licence

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completed

Purpose

Provide a detailed account of GA's revision of the stratigraphy of the South Nicholson region, in collaboration with the NTGS release of the new 3rd Edition MOUNT DRUMMOND 1:250K mapsheet

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asNeeded

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geoscientificInformation

Series Information

Australian Journal of Earth Sciences

Lineage

<div>Paper based on an extensive collection of detrital zircon geochronology analyses, conducted as part of the South Nicholson EFTF program 2016-2022</div>

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[-19.5, -17.5, 139, 136]

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Spatial Resolution

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