Minerals Alert

July 2014

A monthly online newsletter with product news, data releases and project highlights relating to the minerals and energy exploration industries.

  1. Stavely Greenfields Drilling Project
  2. Stratigraphic information helps regional understanding
  3. Map for Nickel-PGE Explorers
  4. The late Tim O'Driscoll lineament maps available
  5. Geoscience Australia's minerals-based presentations at the AESC
  6. Update on geophysical data releases
  7. About Minerals Alert

1. Stavely Greenfields Drilling Project

The Stavely Greenfields Drilling Project is a collaborative program being undertaken in the prospective Stavely Zone of western Victoria with the Geological Survey of Victoria, in partnership with the Deep Exploration Technologies Cooperative Research Centre (DET CRC). The program will involve the drilling of 15 holes through cover into fresh basement rocks in order to test geological models and assess the potential for a range of mineral systems, with a focus on porphyry copper-gold and volcanic-hosted massive sulphide systems.

To date, 14 of the proposed 15 drill sites have been occupied. Where basement rocks have been covered by recent material, sonic drilling techniques have been used to penetrate to basement before finishing the holes with tails drilled using conventional diamond drill rigs. The use of sonic drilling has enabled near 100% recovery of unconsolidated cover materials, and provides some of the most complete stratigraphic holes through the Murray Basin. These will be invaluable for further cover-based studies and analysis for distal footprint signatures of basement-hosted mineralisation. The deepest sonic hole penetrated to a depth of 212m, marking the deepest hole drilled using this method in Australia.

Follow-up diamond drilling has been completed at six of the planned holes, and has intersected Cambrian ultramafic, mafic and intermediate igneous rocks, as well as turbidite sequences and covered Grampians Group sediments. Rocks exhibiting alteration and minor sulphides have also been intersected. Intervals of anomalous element concentrations have been identified with the assistance of Lab-at-Rig™ technologies deployed by the DET CRC, which provides near real-time multi-element geochemical analyses. The program has completed approximately 1100m of sonic drilling and 500m of diamond drilling to date.

2. Stratigraphic information helps regional understanding

The Australian Stratigraphic Units Database (ASUD) is the single point of truth for lithostratigraphic and sequence stratigraphic units in Australia. It is maintained by Geoscience Australia staff for the Australian Stratigraphy Commission, and we work closely with staff in the State and Territory geological surveys. The database includes ~16,800 current units and >34, 000 other units.

We index maps, data sets and publications including journal articles for stratigraphic information, and record unit definitions approved by the Australian Stratigraphy Commission. New State/Territory Survey maps and explanatory reports are given high priority on the basis of trying to capture new and reliable information as quickly as possible. The information in the ASUD provides the stratigraphic underpinning to geological maps and datasets produced by Geoscience Australia, for example the `Surface Geology of Australia 1:1 million scale dataset'. The completeness of an individual unit's record varies. Useful data for mineral explorers may, however, include descriptions of rocktype, age, contact relationships, stratigraphic thickness and references.

Two search pages are available at our website.

The 'Stratigraphic Units Search' page provides reports for individual stratigraphic units. For larger regional searches, the 'Whole State Searches' page provides vertical bar delimited (|) data in ASCII format which can be displayed in MS Excel, or other formats.

Staff from the Geochronology and Stratigraphy Section will be attending the Australian Earth Sciences Convention in Newcastle, 7-11 July 2014. They will present a poster on maintaining quality in the Australian Stratigraphic Units Database (ASUD), convene a meeting of the Australian Stratigraphy Commission, and present a workshop on 'Establishing and defining stratigraphic units'.

Further information on the  ASUD  and Australian procedures for establishing new stratigraphic units is currently available on the Geoscience  Australia website or by contacting stratnames@ga.gov.au or cathy.brown@ga.gov.au or phone +61 2 6249 9535.

3. Map for Nickel-PGE Explorers

A new GIS map dataset - Australian mafic-ultramafic magmatic events is now available online, and is a compilation of mafic-ultramafic igneous rock units for the Australian continent, grouped into 74 distinct magmatic events from the Archean to the Cenozoic.

The dataset provides information on known mineral provinces as well as on under-explored and potentially mineralised geological environments in Australia, and will be particularly useful for nickel, platinum-group element (PGE) and chromium mineral exploration. This dataset also provides important information on the extent of mafic and ultramafic igneous rocks under sedimentary and regolith cover, and gives insights into the geodynamic development of the Australian continent over time. The dataset is available as a free download.

For further information,  please email Jane.Thorne@ga.gov.au, or phone +61 2 6249 9596.

4. The late Tim O'Driscoll lineament maps available

The late Tim O'Driscoll  spent many decades interpreting linear features in magnetic, gravity and other  remote sensed data. This work was done at local, regional and continental  scales. The Geoscience Australia Library has been gifted many of his original  interpretations on both paper and film. These are important historical  documents, all the more so because O'Driscoll's lineaments were one of the key  inputs that led to Western Mining Corporation's successful discovery of Olympic  Dam in 1975. Geoscience Australia has made this resource available by scanning  and rectifying 133 map and compilation sheets. Where possible rectification was validated using topographic features, including rivers, roads, rail, towns etc. Information available for free download.

5. Geoscience Australia's minerals-based presentations at the AESC

The Australian Earth Science Convention is being held in Newcastle (NSW) 7-10 July 2014. Geoscience Australia is sponsoring this event,  has a booth display and is presenting talks and posters on its work.  We are presenting the following  Minerals-related work:

  • Pre-Competitive Minerals Activities In The Southern Thomson Orogen: Unlocking The Region's Hidden Resource Potential
  • Deciphering The Structural Framework Of The Central And Southern Thomson Orogen, Australia
  • The Crust Beneath The Nullarbor: First Images Of The Eucla-Gawler Deep Seismic Reflection Line (13ga-Eg1)
  • Magmatic Ni-Pge Mineral Systems Framework For Australia: Magmatic Events And Their Prospectivity
  • Australian Mafic-Ultramafic Magmatic Events: A Gis Framework For Systems Analysis
  • The Australian Stratigraphic Units Database - Maintaining Quality Data Behind The Scenes

6. Update on geophysical data releases

Geoscience Australia is managing the geophysical data acquisition programs in Western Australia, Victoria, New South Wales, Queensland and the Northern Territory.

The current status of Geoscience Australia's geophysical survey data acquisition is available in a comprehensive table.

To obtain further details on the survey acquisition, please email murray.richardson@ga.gov.au, or phone +61 2 6249 9229.

7. About Minerals Alert

For more information, please email andrew.barrett@ga.gov.au, or phone +61 2 6249 9502.

To read past editions of Geoscience Australia's Minerals Alert, visit the Minerals Alert Newsletter Archive.

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