Frontier basins

Many of the Northern Territory's onshore basins are known to be prospective but are underexplored and therefore classed as frontier petroleum basins.

These basins have undergone various degrees of exploration, with some having:

  • Known petroleum systems and reasonable coverage of seismic data and exploration wells - Georgina Basin, Pedirka Basin
  • Little to no seismic or well coverage - Wiso Basin, South Nicholson Basin, Lawn Hill Platform.

The Georgina Basin is a Cryogenian to Devonian basin approximately 330,000km2 in area in central Northern Territory and extending into western Queensland. The northern and central part of the basin comprise a relatively shallow platformal Cambrian succession, whereas the southern parts of the basin contain a thicker Neoproterozoic to Devonian succession.

In the southern Georgina Basin, the middle Cambrian succession including the Thorntonia Limestone, the Arthur Creek and Chabalowe formations contain productive marine source rocks. Numerous conventional stratigraphic and structural traps are present within the basin, which also has considerable shale gas and oil potential in the Arthur Creek Formation.

More detailed description of the petroleum potential of the Georgina Basin can be found in NTGS Report 22. The southern Georgina Basin has good seismic and petroleum well coverage.

Open file petroleum company reports and all NTGS data and information on Georgina Basin can be found on the GEMIS website.

The early Palaeozoic Warburton Basin, late Palaeozoic Pedirka Basin and Mesozoic Eromanga Basin are three stacked basins in the southeastern corner of the NT (Simpson Desert area) that extend over areas of adjoining Qld, SA and NSW. The exposed Eromanga Basin overlies the Pedirka Basin, which is largely restricted to the subsurface. The Warburton Basin is entirely concealed beneath the Pedirka and Eromanga basins.

No commercial petroleum has been discovered in these stacked basins in the NT, but there are good petroleum indications in drillholes. At least three unnamed petroleum systems are present in the Simpson Desert area; these incorporate source rocks of the Permian Purni and Triassic Peera Peera formations (Pedirka Basin), and the Early Jurassic Poolowanna Formation (Eromanga Basin), plus a number of possible reservoir configurations. Late Palaeozoic and Mesozoic rocks remain the primary exploration targets for conventional petroleum, but underlying Palaeozoic (Cambrian to Devonian) clastic and carbonate rocks provide significant secondary objectives. The Toolebuc Formation and overlying basal Allaru Mudstone of the Eromanga Basin are also prospective for unconventional hydrocarbons.

The Simpson Desert area is extensively covered by seismic acquisition and several petroleum wells.

NTGS Report 22 provides an overview of the petroleum potential of the Warburton, Pedirka and Eromanga basins.

Open file petroleum company reports and all NTGS data and information including maps and GIS products on the Warburton, Pedirka and Eromanga basins are available from the GEMIS website.

The Neoproterozoic to Carboniferous Ngalia Basin is a 16,000km2 structurally preserved remnant of the Centralian Superbasin, and is thought to have been originally contiguous with the Amadeus Basin.

The Ngalia Basin is interpreted as a structural and depositional analog of the oil- and gas-bearing Amadeus Basin to the south, although the sedimentary succession is less complete and is more condensed. It is underexplored for hydrocarbons and its potential for both conventional and unconventional petroleum is therefore largely speculative.

Petroleum systems have not been clearly defined and only minor gas shows have been reported from the few drillholes that penetrate the succession. Petroleum well and seismic coverage is limited.

NTGS Report 22 provides an overview of the petroleum potential of the Ngalia Basin.

Open file petroleum company reports and all NTGS data and information including maps and GIS products on the Ngalia Basin can be found on the GEMIS website.

The Palaeozoic Wiso Basin is a large intracratonic basin in the central western Northern Territory that forms part of the Centralian Superbasin.

The majority of the Wiso Basin is shallow, containing less than 300m of platformal middle Cambrian rocks. The main depocentre is the Lander Trough in the south of the basin, which deepens to a maximum interpreted succession thickness of 4500m of Cambrian, Ordovician and Devonian rocks. The Lander Trough is considered geologically analogous to the southern Georgina Basin, which is known to contain productive source rocks.
The Wiso Basin is underexplored with no petroleum or deep stratigraphic wells and very little seismic coverage. Minor hydrocarbon shows have been noted in the Montejinni Limestone intersected in two Bureau of Mineral Resources wells.

NTGS Report 22 provides an overview of the petroleum potential of the Wiso Basin.

Open file petroleum company reports and all NTGS data and information including maps and GIS products on the Wiso Basin can be found on the GEMIS website.

The South Nicholson Basin is a succession of predominantly sandstone and siltstone that outcrops in the northeastern Northern Territory and western Queensland, and which underlies large areas of the central Georgina Basin. It has a maximum thickness of at least 6km and is correlated with the Mesoproterozoic Roper Group of the McArthur Basin that contains substantial shale gas resources within the Beetaloo Sub-basin.

The stratigraphy of the South Nicholson Basin unconformably overlies rocks of the Lawn Hill Platform that extends in western Queensland. The Lawn Hill Platform is correlated with the prospective Palaeoproterozoic McArthur Group of the McArthur Basin and is known to have productive source rocks in adjacent regions of Queensland.

To date, the South Nicholson Basin and Lawn Hill Platform have received little to no exploration interest in the Northern Territory with no industry seismic data and only one petroleum well. Further information on the petroleum potential of these two basins can be found in NTGS Report 22.

Given the correlation of their stratigraphy with proven petroleum systems in the McArthur Basin, these basins are the focus of regional scale investigation by NTGS through the Resourcing the Territory initiative and by Geoscience Australia through the Exploring for the Future program. Through these Northern Territory and Commonwealth government funded initiatives, regional scale seismic data has been acquired for the first time over the South Nicholson Basin and Lawn Hill Platform. Further studies to improve the understanding of the petroleum potential of these basins is continuing under these initiatives.

All NTGS data and information including maps and GIS products on the South Nicholson Basin and Lawn Hill Platform can be found on the GEMIS website.