Greater McArthur Basin statigraphic characterisation
The Greater McArthur Basin is a regional correlation between the Palaeo- to Mesoproterozoic McArthur and Birrindudu basins and the Tomkinson Province. It has an approximate area of 550,000 km2 in the northern NT.
Northern Territory Geological Survey (NTGS) projects in the greater McArthur Basin aim to -
- develop an understanding of the basins architecture and tectonic framework, and resolve the relative timing of tectonism across its major structural elements.
- characterise and clarify its depositional history through typing of major stratigraphic units, and address existing issues of correlation across the basin.
- Integrate the tectonic and stratigraphic history of the basin to provide the basis for identification of mineral deposit models related to specific stratigraphic units, identification of key fluid pathways and timing, and provide valuable datasets to assist with mineral and hydrocarbon exploration.
The stratigraphic characterisation project focuses on characterising and clarifying the depositional history of the greater McArthur Basin, with a particular focus on better defining correlation of units across this large region.
The work will comprise targeted description and sampling of type areas and key exposures for all of the following:
- geochronology (provenance and maximum deposition ages)
- whole rock geochemistry
- stable isotope geochemistry, hyperspectral data
- rock property data (eg magnetic susceptibility)
- petrography and detailed lithological descriptions.
In 2014 the project focused on:
- the Roper Group of the McArthur Basin
- the Renner Group of the Tomkinson Province
- the Tijunna Group of the Birrindudu Basin.
In 2015 the project will extend to the Glyde package of the McArthur Basin, including units in the northern part of the basin, and equivalents in the Birrindudu Basin and Tomkinson Province.
- all units fully described and illustrated, including distribution, field and petrographic characteristics, and depositional setting
- revised depositional modelinvolves repeated progradation of deltas and shorelines across shallow-marine shelf
- LA-ICPMS detrital zircon geochronologyoffers potential for inter- and intrabasinal correlation with resolution at subgroup scale -
- Tijunna Group probably correlates with Maiwok Subgroup of Roper Group.
- Jamison sandstone and Hayfield mudstone form distinct sedimentary package in Beetaloo Sub-basin, significantly younger than Roper Group
- Hf data has been collected and will add further refinement to the understanding of sediment source areas
CODES – ARC Centre of Excellence in Ore Deposits, University of Tasmania
Munson TJ, 2016. Sedimentary characterisation and correlation of the Wilton package, greater McArthur Basin. Annual Geoscience Exploration Seminar (AGES) Proceedings, Alice Springs, Northern Territory, 15–16 March 2016. Northern Territory Geological Survey, Darwin.