Minerals Alert

February 2018

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

  1. GA Minerals Forum presentations available online
  2. GA at the 2018 AEGC (Australasian Exploration Geoscience Conference)
  3. New geochronology reports and data available
  4. Geophysical estimates of cover thickness: two new case studies available
  5. Update on geophysical data release
  6. About Minerals Alert

1. GA Minerals Forum presentations available

The Minerals Systems Branch  delivered a series of presentations at a public forum in Canberra on 12 December  2017. Those presentations are now available online for download. The presentations cover the themes: (i) Cover, (ii)  3D architecture, (iii) 4D geodynamics, and (iv) Mineral Systems Footprints and  Toolkits.  As well as covering a range of  current activities within the Mineral Systems Branch, the presentations  emphasise new projects arising from the Australian Government's four year Exploring for the Future Programme,  which commenced in 2016.

2. GA  at the 2018 AEGC (Australasian Exploration Geoscience Conference)

Geoscience Australia will be at the First Australasian Exploration  Geoscience Conference (AEGC) in Sydney at the International Convention Centre  from 18-21 February 2018.  The Conference  is being jointly organized by the Australian Society of Exploration  Geophysicists Ltd, the Australian Institute of Geoscientists Ltd and the  Petroleum Exploration Society of Australia Ltd.   Presentations, both oral and poster, will be  given on the various geoscientific programs conducted by Geoscience Australia  and will include results from the  Exploring for the Future initiative and recent  geophysical surveys in Australia that have collected passive seismic,  magnetotelluric, ocean-bottom seismometer, airborne electromagnetic, magnetic,  radiometric, gravity and seismic datasets.   If you are in Sydney at this time please come and visit the Geoscience Australia  booth (Numbers 75 & 76) in the exhibition hall for more information about  the numerous geoscientific activities at Geoscience Australia.
The presenters, their topics and presentation schedule are available  from the conference website at www.aegc2018.com.au.

3. New geochronology reports and data available

     
  • Northern  Territory Geological Survey Record 2017-011 by Kositcin and McGloin reports  new SHRIMP U-Pb zircon ages from two granite samples from the Aileron Province,  Northern Territory.
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  • Northern  Territory Geological Survey Record 2017-012 by Kositcin, Munson and Whelan reports  new SHRIMP U-Pb detrital zircon ages from 11 sedimentary samples from the greater  McArthur Basin, Northern Territory.
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  • Geoscience  Australia Record 2017/16 by Kositcin and Carson reports new SHRIMP U-Pb  detrital zircon ages from 9 sedimentary samples from the Birrindudu and  Victoria Basins, Northern Territory. These results complement those previously  presented in Carson, 2013, Australian Journal of Earth Sciences 60, 175 – 196,  and provide an understanding of the evolving sedimentary provenance through the  Proterozoic in this part of northern Australia.
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  • Geoscience  Australia Record 2017/20 by Lewis reports new SHRIMP U-Pb detrital zircon  ages from 9 samples from the GSWA Harvey 1 drill-hole in the southern onshore  Perth Basin, Western Australia.
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  • Geological  Survey of South Australia Report Book 2015/0003 by Jagodzinski and Reid  reports U-Pb SHRIMP and LA-ICPMS, and 40Ar/39Ar results  from over 30 samples from a range of minerals and energy prospects across South  Australia.
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  • Geological  Survey of Western Australia Report 161 by Maidment reports new SHRIMP U-Pb  zircon ages, as well as associated whole-rock geochemistry Sm-Nd isotopic  results, from 15 samples from the Rudall Province, Western Australia.

In each of these studies,  U-Pb results were acquired in Geoscience Australia’s in-house SHRIMP  laboratory, in some cases under National Collaboration Framework agreements  between Geoscience Australia and the relevant State or Territory geological  survey. SHRIMP U-Pb Geochronology data presented and discussed in each of these  Records are also available for download via Geoscience Australia’s Geochron  Delivery system.

     
  • Geoscience  Australia Record 2017/22 by Anderson et al. presents a compilation of  available U-Pb SHRIMP and LA-ICP-MS ages from across Queensland, Northern  Territory and parts of Western Australia and South Australia. More than 2200  age results were compiled in a consistent format in spreadsheet form to  facilitate use in GIS layers, and example thematic age maps are presented in  the Record.  This work was conducted as  part of the Exploring for the Future programme, a four-year initiative funded by the Australian Government to better  understand the mineral, energy and groundwater resources in northern Australia  and parts of South Australia.
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  • Bowden, B. et al. 2017. Mineralium Deposita 52, 863-881.   This study presents new U-Pb and 40Ar/39Ar age  results from the Prominent Hill iron-oxide copper-gold (IOCG) deposit in South  Australia.
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  • Cross, A. J. & Williams, I. S., in press. Chemical Geology. This study presents a  new method for correction of so-called matrix effects during SHRIMP  geochronology analyses of the mineral xenotime (YPO4).

For further information on  geochronology at Geoscience Australia, please email: geochronology@ga.gov.au.

4. Geophysical estimates of cover thickness: two new case studies available

Release of GA  Record 2017/021:  Estimating Cover Thickness in the Southern Thomson Orogen - Results from the  pre-drilling application of refraction seismic, audio-magnetotelluric and  targeted magnetic inversion modelling methods on proposed borehole sites.
This report details the  acquisition, processing, modelling and interpretation of geophysics techniques  used for estimating cover thickness at 16 proposed borehole sites throughout  the southern Thomson Orogen in New South Wales and Queensland. A detailed  discussion of the limits and uncertainties associated with each technique is  also included. The cover thickness estimates presented in this report were used  to lower the risks associated with the southern Thomson Orogen stratigraphic  drilling program by reducing the uncertainty in intersecting the target  stratigraphy at each of the proposed borehole sites, as well as allowing for  better project and program planning. Successful completion of the stratigraphic  drilling program in the southern Thomson Orogen will allow for each of these  geophysical methods for estimating cover thickness to be benchmarked using  actual cover thicknesses measured in the boreholes. The Southern Thomson  Project is a collaboration between Geoscience Australia (GA) and its state  partners the Geological Survey of New South Wales (GSNSW) and Geological Survey  of Queensland (GSQ).

Release of GA Record 2017/19: Cover Thickness Estimates in the Coompana Province,  South Australia: Benchmarking and  results from the pre-drilling geophysics program – Magnetotellurics.
A partnership between the Geological Survey of  South Australia (GSSA) and Geoscience Australia (GA) was formed to undertake a  regional drilling program in the Coompana Province, which is completely covered  by Neoproterozoic to Cenozoic sediments with no known records of outcropping  basement. The geophysical technique of magnetotellurics (MT) was applied to  estimate cover thickness at the proposed drillhole sites as part of a  pre-drilling geophysics field program. Comparison with historic drillhole  results indicates that the MT method is capable of identifying major  stratigraphic structures and providing cover thickness estimates with a  reasonable accuracy (within 10%). Subsequently, estimates of cover thickness at  eight proposed drillhole sites are derived from the MT data and are provided to  assist the Coompana Drilling Program in April 2017. Details of MT data  acquisition and processing, data inversion and preliminary interpretation of  model results are presented in this report.

5. Update on geophysical data release

Geoscience Australia is managing the geophysical data acquisition programs in Western Australia, Victoria, New South Wales, Queensland, Tasmania and the Northern Territory on behalf of the state/territory geological surveys.

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

For further information, email clientservices@ga.gov.au or phone 1800 800 173.

6. About Minerals Alert

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

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

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