Minerals Alert June 2014

June 2014

A monthly online newsletter with product news, data releases and projects relating to the minerals and energy exploration industry.

  1. Geochronology at Geoscience Australia
  2. Onshore Seismic Surveys now available through a web service
  3. Airborne Geophysical Data Panel Refresh
  4. Update on geophysical data releases
  5. About Minerals Alert

1. Geochronology at Geoscience Australia

Isotope geochronology is a key tool at Geoscience Australia, providing new insights into the geological evolution of the continent, and underpinning improved tectonic models and mineral systems predictions.

The central component of Geoscience Australia¿s geochronology program is U-Pb dating (predominantly of zircon) via Sensitive High Resolution Ion Microprobe (SHRIMP). These ages constrain the timing of magmatic, metamorphic and hydrothermal events, and are also used to characterise the provenance of sedimentary rocks. Datasets are available for download via the Geochron Delivery system. SHRIMP data are complemented by other isotopic methods such as Chemical Abrasion Thermal Ionisation Mass Spectrometry (CA-TIMS) U-Pb, 40Ar-39Ar, Re-Os, and K-Ar.

Current projects of which geochronology forms an integral part include:

Stavely Drilling Project

As a contribution to the UNCOVER initiative Geoscience Australia and the Geological Survey of Victoria are currently drilling in the Stavely region of western Victoria in an effort to evaluate the mineral prospectivity of basement rocks buried beneath cover. Geochronology will be conducted on key samples from these drill-holes to test greenfields mineral systems models.

Southern Thomson Orogen Project

An extensive program of geochronology is in progress in the southern Thomson Orogen of northern NSW and southern Queensland to improve stratigraphic understanding, and the timing of magmatic and mineralisation events.

State/Territory Geological Survey Mapping Projects

Collaborative geochronology conducted at Geoscience Australia supports mapping projects being conducted by the geological surveys of the Northern Territory, Queensland, New South Wales, Victoria, South Australia and Tasmania.

Timescale refinement in Permian coal-bearing basins of eastern Australia

High precision U-Pb CA-TIMS ages are being used to constrain the ages of the predominantly non-marine successions within the coal-bearing Sydney, Bowen and Gunnedah basins. The results are being used to; (i) improve inter-basin lithostratigraphic correlations between coal-bearing successions, and (ii) refine the calibration of the eastern Australia spore-pollen zonation in the international Geological Time Scale 2012.

Examples of recent reports and journal articles arising from these various projects include:

Bodorkos, S., Blevin, P.L., Simpson, C.J., Gilmore, P.J., Glen, R.A., Greenfield, J.E., Hegarty, R., Quinn, C.D., 2013. New SHRIMP U-Pb zircon ages from the Lachlan, Thomson and Delamerian orogens, New South Wales: July 2009-June 2010. Geoscience Australia. Record 2013/29, 124p.

Carson, C.J., 2013. The Victoria and Birrindudu Basins, Victoria River region, Northern Territory, Australia: a SHRIMP U-Pb detrital zircon and Sm-Nd study. Australian Journal of Earth Sciences 60(2), pp175-196.

Chisholm, E.I., Fitzherbert, J.A., Deyssing, L., Simpson, C.J., 2014. New SHRIMP U-Pb zircon ages from the Captains Flat area, eastern Lachlan Orogen, New South Wales: July 2012-June 2013. Geoscience Australia. Record 2014/07, 47p.

Cross, A.J., Bultitude, R.J., Purdy, D.J., 2013. Summary of Results - Joint GSQ-GA Geochronology Project: Ayr, Bowen, Eulo, Mount Coolon, Proserpine and Warwick 1:250 000 Sheet areas. Queensland Geological Record 2012/19, CD.

Fraser, G., Reid, A., Stern, R., 2012. Timing of deformation and exhumation across the Karari Shear Zone, north-western Gawler Craton, South Australia . Australian Journal of Earth Sciences 59(4), pp547-570.

Kositcin, N., Whelan, J.A., Hallett, L. and Beyer, E.E., 2014. Summary of results. Joint NTGS-GA geochronology project: Amadeus Basin, Arunta Region and Murphy Province, July 2012-June 2013. Northern Territory Geological Survey, Record 2014-005.

Kositcin, N., Everard, J.L., 2013. New SHRIMP U-Pb zircon ages from Tasmania: July 2012-June 2013. Geoscience Australia. Record 2013/22, 55p.

2. Onshore Seismic Surveys now available through a web service

Australia has around 22 700 km of onshore deep-seismic reflection data. These data provide unique insights into the crustal structure of the continent, which is essential for an understanding how and when Australia evolved. It is through this understanding that assessments of many of the nation's mineral, energy and water resource potential can be made. These deep seismic reflection data have been collected over the past 40 years by Geoscience Australia in collaboration with the State/Northern Territory geological surveys and with AuScope.

The full suite of data is now available to download through a Web Map Service (WMS) - http://www.ga.gov.au/gis/services/earth_science/GA_Onshore_Seismic_Surveys/MapServer/WMSServer

The new Web Map Service shows the locations of seismic lines which can be queried in a GIS application such as ArcMap or QGis, or through an online portal such as the AuScope Portal. The query result for each survey line contains metadata about survey specifications, and links to all downloadable files including SEGY data and interpreted cross sections.

To view the Onshore Seismic Surveys web service in the AuScope Portal, go to http://portal.auscope.org/portal/gmap.html. Then

  1. Choose the "Registered" layers tab
  2. Scroll down to the list of "Geoscience Australia" layers, and click "GA Onshore Seismic Surveys"
  3. Click "Add Layer to Map". The survey lines will appear on the map.
  4. Click on a line to query it and view basic survey metadata.
  5. Click on the "URL" attribute to view full metadata and links to download data files.

3. Airborne Geophysical Data Panel Refresh

Geoscience Australia recently refreshed the Panel for the Acquisition, Processing and Supply of Airborne Geophysical Data (magnetic and radiometric) via RFT 2014/409 which closed on 31 March. Geoscience Australia is pleased to announce that a new supplier, MAGSPEC Airborne Surveys Pty Ltd from WA, has been added as a member of the Airborne Geophysical Data Panel for participation on future procurement for airborne magnetic and radiometric data that Geoscience Australia may require from time to time. This Deed was executed by Geoscience Australia on 21 May and expires on 30 June 2016 as for current existing members of the Airborne Geophysical Data Panel. The current membership of the panel comprises:

  • CGG Aviation (Australia) Pty Ltd
  • GPX Surveys Pty Ltd
  • MagSpec Airborne Surveys Pty Ltd
  • Sander Geophysics Ltd
  • Thomson Aviation Pty Ltd
  • Universal Tracking Systems Pty Ltd

4. 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.

Minerals Alert Geophysical Surveys Table - survey boundary polygons in MapInfo TAB format.

5. About Minerals Alert

For more information, please email clientservices@ga.gov.au; or phone 1800 800 173.