Minerals Alert September 2003
- Geoscience Australia Annual Minerals Seminars
- Yilgarn Craton Online GIS
- Airborne Gravity Survey West Arnhem Land, Northern Territory
- Seismic Acquisition Olympic Dam region, South Australia
- Hydrogeochemistry Used to Vector Towards Mineralisation Under Cover
- North Australia Project 2003 Field Program
- Airborne Geophysical and Gravity Program Leader Leaves
- About Email Alert
Geoscience Australia will be hosting two one-day seminars to present the results of its research to the mineral exploration community later this year. Full details of the seminar program are currently being finalised. The first seminar will be held in Brisbane at The Eagle Street Conference Centre on Tuesday 18 November and a second will be held at The Esplanade Hotel in Fremantle on Thursday 4 December 2003.
If you would like to receive information on these seminars as it becomes available please contact Mike Huleatt on +61 (0)2 6249 9087 or by email at Mike.Huleatt@ga.gov.au.
The Yilgarn online GIS displays a wide range of data including geological datasets, topographical data, geophysical images and seismic traverses, whole rock geochemistry and geochronology samples. It provides an aeromagnetic interpretation (lithology distribution and structure) and a geological interpretation of the Archaean Yilgarn Craton, one of Australia's key mineral provinces. The online GIS also focuses on the Leonora-Neale Transect, by providing a detailed solid geology interpretation of the section. The Yilgarn Craton is in Western Australia and covers 20% of the Australian continent. Exposure of bedrock is extremely poor throughout the region and most known mineral deposits occur within or adjacent to sparse outcrop. The online GIS provides a view through the poorly magnetised cover to display bedrock distribution. Interpreted rock types of the region include granite, granitic gneiss, layered intrusions and sills. Interpreted structural elements include lithologi! cal banding, faults, and dyke swarms. Also presented are several surrounding and partially overlying Proterozoic and Phanerozoic basins and provinces. The Yilgarn Craton is arguably Australia's premier mineral province, attracting more than half the mineral exploration expenditure, and producing two thirds of the gold and most of the nickel mined in the country. For this reason, the online GIS provides the ability to display all deposits in the region or the option of displaying gold or nickel deposits only. Distribution of mineral deposits can be compared to other data layers including geology, and aeromagnetic domains.
For more details and to view the GIS visit Yilgarn Craton GeoPDF
Geoscience Australia, with the Northern Territory Geological Survey and private companies, is contributing to an airborne gravity survey conducted by Fugro Airborne Surveys employing the GT2A gravity meter supplied by Canadian Microgravity. The GT2A system records the vertical component of the total gravity field, in contrast to airborne gravity gradiometers such as Falcon. Previous tests of the GT2A meter, conducted in the Kalgoorlie region, indicated a repeatability of about 0.5 mgal when a 220 s filter was applied to the data. The survey is being conducted in the west Arnhem Land region of the Northern Territory and is expected to be completed in the first half of September.
Contact Mario Bacchin on +61 (0)2 6249 9308 or at Mario.Bacchin@ga.gov.au.
Geoscience Australia completed the acquisition of 250 km of seismic profiles centred on Olympic Dam, South Australia, in August. The data were acquired on two lines - a longer line oriented approximately NNE-SSW along the Woomera-Olympic Dam and Borefield roads, and a shorter line oriented E-W. The field plots show the data to be of high quality, with a range of different structural styles north and south of Olympic Dam. Data processing has commenced and should be completed for a data release in early-mid-2004. Data were acquired using the ANSIR major national research facility.
Contact Roger Skirrow on +61 (0)2 6249 9442 or at Roger.Skirrow@ga.gov.au
A geochemical and isotopic survey of groundwater composition in the Broken Hill region is highlighting areas where mineralisation under cover may exist. The results stem from the combination of trace element analysis with isotopic analysis of mainly sulfur and lead. Mineralisation in the area has specific sulfur and lead isotopic signatures, and these are being used to identify samples that may have been in contact with oxidising sulfides. The addition of trace element concentrations (Cu, Zn) and reactive transport modelling suggests that, in a number of places, the groundwaters were sampled from within a few kilometres from mineralisation. This tool has the potential to be used in combination with the more conventional exploration arsenal, particularly in the role of area selection for further testing and target ranking. It is particularly effective in areas of thin to thick regolith cover, which is where significant future mineral discoveries in Australia are most likel! y to be made.
The North Australia Project is in the middle of its field program for 2003, the results of which will be reported at AGES in March 2004. This program is being undertaken in close collaboration with NTGS geologists. The fieldwork addresses five problems identified in the last three years of the project:
- Arunta-Davenport transect: assessment of the effects of the Strangways and Chewings orogenies, dating supracrustal units in the Davenport, and dating mineral systems in the Davenport.
- Tanami geochronology: determining the ages of poorly constrained units in the Tanami Region.
- High-grade metamorphism: determining the ages of undated high-grade metamorphic rocks in the Arunta.
- Fluids in the Birrindudu area: documenting fluid types that have affected the Birrindudu region north of the Tanami.
- Mineral systems in the eastern Huckitta 2:250 000 sheet: Documenting, dating and synthesising Cu-Au-W-Pb-Zn-Mo mineral systems between Molyhil and Jervois.
For more information contact David Huston on +61 (0)2 6249 9577 or David.Huston@ga.gov.au.
Ian Hone is resigning from Geoscience Australia on 22 September, after 30 years working on a range of geophysical programs. Ian will be known to many people for his leadership over recent years of Geoscience Australia's airborne geophysical and gravity programs. We wish Ian well for the future.
Any queries regarding Geoscience Australia's airborne data should now be directed to Mr Murray Richardson on +61 (0)2 6249 9229 or at Murray.Richardson@ga.gov.au. Queries regarding gravity data should be directed to Mr Mario Bacchin on +61 (0)2 6249 9308 or at Mario.Bacchin@ga.gov.au.
For more information contact Mike Huleatt on +61 (0)2 6149 9087 or by email at Mike.Huleatt@ga.gov.au
For more information contact Mike Huleatt on +61 2 6249 9087 or email email@example.com.
To view past editions of Geoscience Australia's Minerals Alert, visit the Minerals Alert Newsletter Archive.
Topic contact: firstname.lastname@example.org Last updated: October 4, 2013