Regional Drilling Projects

In addition to other pre-competitive datasets, stratigraphic drilling will be acquired in key regions. The drilling will test geological models of undercover greenfield regions and also provide valuable core samples for a range of analytical studies.

Two-page spread showing the geological map of Australia by major rock types and showing the main pre-competitive data acquisition regions. Three rectangular regions include: Lake Woods in the Northern Territory, the southern Thomson region around the New South Wales and Queensland border, the Stavely in western Victoria. Other activities include deep seismic interpretation transects in the Albany–Fraser and Tropicana regions of southeastern Western Australia and new deep seismic acquisition in northwest Queensland, the Nullarbor Plain of Western Australia and South Australia and the Yathong Trough region of central New South Wales. Small dots spaced every 55 km across the continent mark the location of planned long-period magnetotelluric station sites.

Location of pre-competitive activities in 2013–14.
All activities involve the co-investment with the
states and Northern Territory geological surveys,
together with AuScope. The AusLAMP
magnetotelluric survey will be a multi-year project,
starting in Victoria. Deep seismic reflection lines
will be collected in Western Australia and
South Australia, completing a seismic transect
of the continent, as well as North Queensland
and central New South Wales. The Albany–Fraser
Orogen lines in southeast Western Australia will
be interpreted and results delivered. The southern
Thomson and Stavely regions are highlighted for
drilling and detailed geophysical and surface
geochemical data acquisition. Lake Woods will
be a focus for groundwater geochemical sampling
and analysis.

The selection of these regions has been guided by a range of factors, including:

  • whether a pre-competitive geoscience programme can change industry behaviour
  • the likely thickness of cover (<500 m)
  • the level of co-investment from jurisdictions
  • cross-border opportunities for collaboration
  • estimated mineral potential, and/or
  • degree of basic knowledge gaps.

Geoscience Australia is continuing its investment as a research partner in the Deep Exploration Technologies Cooperative Research Centre (DET CRC) External site link. The DET CRC is developing innovative drilling and analysis technology with the aim of making drilling faster, cheaper and more informative for Australian conditions. Geoscience Australia will continue to support this research by using the DET CRC capability to undertake its regional drilling acquisition.

Stavely Zone Drilling Project

Prospective Cambrian igneous rocks of the Delamerian Orogen lie beneath relatively shallow cover rocks in western Victoria. Geoscience Australia and the Geological Survey of Victoria External site link plan to drill a series of stratigraphic holes into these basement rocks to test geological and mineral system models. The drilling tests include determining the stratigraphic continuity of the prospective Stavely Volcanic Complex, sampling buried intrusions that are possible hosts to porphyry-epithermal mineralisation and testing key structures in the region. The results from these drill holes will add significantly to the pre-competitive knowledge base of this greenfield region.

Following a phase of planning and analysis, drilling will commence in autumn 2014. Acquisition of local geophysical data will assist in the drill planning, especially in determining the nature and depth of cover rocks. The results will also inform the overall goal of improving cover predictions. The drilling will be fully cored and subject to the full-spectrum of geological, geophysical, geochemical and geochronological analysis.

Final results will be delivered by June 2015, and will include a comprehensive report, data package and 'explorer kit'. The project will also benefit from early results from the AusLAMP national magnetotelluric initiative.

A truck-mounted drilling rig and attendant water carrier truck and support trucks in an outback landscape.

Drilling cover in the Frome Embayment,
South Australia.

Southern Thomson Orogen Drilling Project

The Thomson Orogen is a large area that lies to the north and west of the Lachlan Orogen in New South Wales, South Australia, Northern Territory and Queensland. Much of it is under the cover of younger sedimentary basins (some up to several kilometres thick) and is thus a poorly understood element of Australia's geology.

The southern Thomson Orogen project will be undertaken by Geoscience Australia, the Geological Survey of New South Wales External site link and the Geological Survey of Queensland External site link in the southern part of the orogen, around the border region of the two States. Activities will include synthesis and integration of available datasets, as well as the acquisition of an ensemble of geophysical and geochemical datasets to allow prediction and testing of models of cover thickness and character, and styles of basement geology. The new understanding derived from this project will inform many future activities, especially those concerned with cover thickness determination and characterisation. A mineral systems analysis will also be conducted to assess the likely mineral potential of the region and to help shape the selection of drilling sites. Drilling, informed by the integrated analysis, is planned for 2014–15.

The region is the focus of a pilot project for the National AEM map as part of the broader goal for improving depth-to-basement predictions. Final results from the southern Thomson Orogen project are planned for delivery in mid-2016.

Topic contact: minerals@ga.gov.au Last updated: November 5, 2013