North Australia Project: Science overview

• Original project description
• North Australia Project modules and related NTGS projects
• Foundations of the North Australian Craton: Paradigm shifts
• Related links

Original project description

The North Australian Craton (NAC) is one of the least understood mega-elements recognised in the Australian Crustal Elements Map (Fig. 1_PDF_420KB). The NAC is bounded in the south by a continental-scale magnetic anomaly (Fig. 2_PDF_160KB). It includes mostly Palaeoproterozoic basement blocks and extends east from the Kimberley Block to North Queensland, incorporating the Pine Creek Orogen, the Tanami region, and the Arnhem, Tennant and Murphy Inliers in the Northern Territory. Although the Arunta Province lies largely to the south of the magnetic anomaly, it contains rock successions (e.g. Lander Rock beds) of broadly similar age and lithology to those in the Tanami Region. The younger history of the combined North Australian Craton-Arunta Province (or the North Australian Craton) is dominated by the deposition of Proterozoic superbasin sequences, including the MacArthur and Victoria-Birrindudu Basins that have been the focus of recent studies under the NABRE project and Neoproterozoic to Palaeozoic Georgina and Amadeus Basins.

The geological make-up of the NAR can be divided into three constituent parts: the Archaean to early Proterozoic foundation (north of the magnetic anomaly), marginal mobile belts (south of the magnetic anomaly) and the overlying superbasins. Modules within the North Australia Project (Fig. 3_PDF_2.2MB) are designed to resolve specific questions about these parts and complement existing Northern Territory Geological Survey (NTGS) projects (Table 1).

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North Australia Project modules and related NTGS projects

Table 1. Links to North Australia Project modules and related NTGS projects.

Foundations of the North Australian Craton: Paradigm shifts

Since starting this project, data has been acquired that fundamentally changes understandings of the foundations of the North Australian Craton (NAC). Wellmar et al. (1995) defined the southern margin of the NAC by a zone of low magnetic response extending from the Canning Basin in the west to the Harts Range Group in the east. Provenance studies suggest that rocks to the north of this magnetic zone in the Tanami region correlate with those to the south in the Arunta region. We now extend the NAC southwards to the southern margin of the Arunta, and interpret the magnetic anomaly as a possible failed early Proterozoic rift.

Our work also has questioned the evidence for Archaean to early Proterozoic (so-called Barramundi) foundation to much of the southern NAC. Our data suggest that most of the Tanami and all of the Arunta was deposited after ~1850 Ma and was derived in large part from Barramundi-aged (1880-1850 Ma) provenance. This requires re-assessment of tectonic models advocated for the formation of the NAC.

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Related links

• NAP minerals promotion
• Science overview
• Current results and products
• Commodity information
• Tanami seismic research
• Early Proterozoic foundations
• Marginal mobile belts
• Historical products
• Tanami 3D model