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

1. New seismic survey in southeast Australia
2. Eastern Yilgarn Craton metamorphism: new results from the pmd*CRC
3. New gravity survey data added to the Australian National Gravity Database
4. Two Geoscience Australia Records released as part of the Onshore Energy Security Program
5. Kombolgie – Pine Creek airbone electromagnetic survey
6. Expanding our knowledge of North Queensland
7. Reliable subsurface models for mineral exploration
8. Cooper Basin region now in 3D
9. Australian mineral exploration retreats from record high
10. Workshop on new seismic and MT datasets in South Australia
11. Update on geophysical data releases
12. About Minerals Alert

1. New seismic survey in southeast Australia

A deep-crustal seismic survey over the Southern Delamerian Fold Belt in southeast Australia has recently been acquired. This survey is a collaborative project between AuScope (an initiative under the National Collaborative Research Infrastructure Strategy), GeoScience Victoria (a division of the Victorian Department of Primary Industries), Department of Primary Industries and Resources, South Australia (PIRSA) and Geoscience Australia.

The survey consisted of two traverses; an east-west trending line (146km) which commenced west of Naracoorte in South Australia and ended near Horsham in Victoria, and a north-south trending line (51km) which crossed the east-west traverse just east of the South Australia/Victoria border. The data from the east-west line complements earlier seismic surveys and will provide a continuous deep seismic transect from the western Lachlan Fold Belt to the eastern Delamerian Fold Belt. Gravity data was collected along the lines also at 400m intervals.

Data from this survey is proposed for release in mid-2010, after processing has been completed.

For further information, email jenny.maher@ga.gov.au; or phone +61 2 6249 9896.

2. Eastern Yilgarn Craton metamorphism: new results from the pmd*CRC

Geoscience Australia Record 2009/023, Metamorphic Evolution and Integrated Terrane Analysis of the Eastern Yilgarn Craton: Rationale, Methods, Outcomes and Interpretation, is a 270-page full-colour report and map on the metamorphic evolution of the Eastern Yilgarn Craton. The work was undertaken between 2006 and 2008 as part of the Predictive Mineral Discovery Co-operative Research Centre (pmd*CRC) by B. Goscombe and others, and is now released into the public domain. The spatial and temporal patterns documented from metamorphic rocks contribute fundamental insights into the history and likely tectonic setting of the region, as well as providing information on the fluid history of the crust and associated mineralisation events.

This Record is underpinned by a comprehensive metamorphic database covering the entire Eastern Yilgarn Craton, which was compiled from pre-existing mapping: 14 500 sites with qualitative metamorphic information and 470 new key sites with detailed quantitative metamorphic data, including pressure (P), temperature (T), temperature/depth ratio and P-T paths. The continual evolution with time of fundamental metamorphic parameters throughout the entire history has been constructed as evolution curves and integrated with the deformation, magmatic, stratigraphic and mineralisation history. This new metamorphic study has contributed significantly also to understanding the world-class gold mineral systems of the region.

For further information, email richard.blewett@ga.gov.au; or phone +61 2 62499713.

3. New gravity survey data added to the Australian National Gravity Database

On 20 November 2009 the confidential infill data collected as part of the 2008 Windimurra Gravity Survey became open file. These 856 stations were collected at 1.6km station spacing as infill to the surrounding 2.5km x 2.5km survey. The Windimurra survey is located in on the Meekatharra and Perth 1:1 million sheet areas, Western Australia.

Open-file company data supplied to Geoscience Australia by GeoScience Victoria were added to the Australian National Gravity Database (ANGD) in November 2009. There were four surveys with a total of 2461 stations located on the Hamilton 1:1 million sheet area.

The choice of fields presented when downloading point-located-gravity data through the Geophysical Archive Data Delivery System (GADDS) has been extended. Additional fields describing various attributes of the point-located-gravity data are now offered for downloading. All relevant alphanumeric fields associated with the gravity observations in the ANGD can now be selected whenever point located gravity data are downloaded. Previously only numeric fields were available.

All open-file data in the Australian National Gravity Database, can be downloaded from GADDS.

For further information, email mario.bacchin@ga.gov.au, or phone +61 2 6249 9308.

4. Two Geoscience Australia Records released as part of the Onshore Energy Security Program

As part of the Onshore Energy Security Program, two Geoscience Australia Records have been released covering North Queensland:

Record 2009/029, 3D maps and supporting geophysical studies in the North Queensland region summarises available geophysical and isotopic data in North Queensland and uses these data to validate seismic interpretations as well as construct regional to semi-regional 3D maps and images of geological elements and of magnetite and hematite-sulfide alteration zones. The data is used also to estimate depth to basement and to model the geodynamic evolution of North Queensland.

For further information, email natalie.kositcin@ga.gov.au; or phone +61 2 6249 9849.

Record 2009/030, Geodynamic Synthesis of the North Queensland Region and Implications for Metallogeny summarises the geology, geodynamic evolution and metallogeny of North Queensland and uses these data to predict areas with mineral potential, including areas under cover, by integrating mineral systems and geodynamic setting.

For further information, email richard.chopping@ga.gov.au, or phone +61 2 6249 9349.

5. Kombolgie – Pine Creek airborne electromagnetic survey

Airborne Electromagnetic (AEM) data for the Kombolgie area of the Pine Creek Project, Northern Territory, was released on 4 December 2009. The data acquired for Geoscience Australia were collected using the VTEM time-domain system on flight lines with spacings of 5km and include a block of infill at 1.66km in the Nabarlek (U) area.

The survey extends southwards from the northern coast line down the eastern side of Kakadu National Park, to just east of Katherine. The survey results provide insights into the local conductivity characteristics of Pine Creek Orogen metamorphic rocks, overlying Kombolgie Subgroup and Mesozoic sedimentary rocks, as well as coastal and estuarine deposits. A very preliminary assessment of the final data suggests that there are discontinuous conductivity anomalies approximating the inferred position of the unconformity between the Pine Creek Orogen metamorphic rocks and the overlying Kombolgie Subgroup sedimentary rocks. The intersection of regional structural features with these conductivity anomalies may well define prime targets for unconformity-uranium mineralisation.

Much of the survey area is underlain by resistive rocks and will therefore be suitable for more detailed AEM surveys in the future.

For further information, email alan.whitaker@ga.gov.au; or phone +61 2 6249 9702.

6. Expanding our knowledge of North Queensland

North Queensland is one of the most richly mineralised regions in Australia, both in terms of total resources, and the variety of commodities and deposit types. To better understand regional geological controls on these resources, especially energy resources, Geoscience Australia, in collaboration with the Geological Survey of Queensland and AuScope, undertook a deep-crustal seismic survey in the region in 2007. The results of this survey and complementary research and syntheses have identified fundamental new crustal boundaries and provinces in North Queensland and point to areas of previously unknown potential for mineral and energy resources.

For further information see the December 2009 issue of AusGeo News.

7. Reliable subsurface models for mineral exploration

The ability to visualise subsurface geological features and materials over a large area is a critical time and money saving tool for mineral explorers. Geoscience Australia and the University of British Columbia Geophysical Inversion Facility researchers have developed a new method for rapidly building 3D geological models using only limited exploration observations. These models are key inputs for generating predictive 3D images of the subsurface from geophysical observations.

For further information see the December 2009 issue of AusGeo News.

8. Cooper Basin region now in 3D

The new Cooper Basin region 3D map will aid explorers in a region identified as highly prospective for geothermal energy. The map incorporates the two fundamental components which define a hot rock geothermal play: the potential heat source (high-heat producing granites) and the thermal insulation (overlying sedimentary rocks).

For further information see the December 2009 issue of AusGeo News.

9. Australian mineral exploration retreats from record high

Australian and global mineral exploration expenditure reached record highs in 2008, but dropped significantly in 2009 as a consequence of the Global Financial Crisis. Australian mineral exploration expenditure fell by 9.7% from a record $2461 million in 2007-08 to $2223 million in 2008-09 according to data from the Australian Bureau of Statistics.

For further information see the December 2009 issue of AusGeo News.

10. Workshop on new seismic and MT datasets in South Australia

There will be a one-day workshop on Thursday 6 May 2010 in Adelaide to present the results of new seismic reflection and refraction and magnetotelluric data collected during 2008 and 2009 in South Australia in conjunction with the Department of Primary Industries and Resources, South Australia. The seismic lines presented include the Curnamona, Gawler-Curnamona link, Arrowie and Eyre Peninsula transects. More details and registration requirements will be available early in 2010.

For further information contact russell.korsch@ga.gov.au; or phone +61 2 6249 9495.

11. Update on geophysical data releases

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

Central Canning, Broome (North Canning 1) and Mt Anderson-McLarty Hills (North Canning 3) Airborne magnetic and radiometric surveys have been released via Geophysical Archive Data Delivery System (GADDS).

For further information, email murray.richardson@ga.gov.au; or phone +61 2 6249 9229.

12. About Minerals Alert

For more information contact Mike Huleatt on +61 2 6249 9087 or email mike.huleatt@ga.gov.au.

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