Minerals Alert August 2004

  1. Geoscience Australia Minerals Division Annual Seminar
  2. Surface geology: Northwest Queensland - western Cape York & Torres Strait (digital)
  3. New information for gold and nickel exploration in the North Australia
  4. Updated 3D model and GIS for the North Australia Craton
  5. Australian Stratigraphic Units Database - updated search features
  6. The Virtual Centre for Geofluids and Thermodynamic Data
  7. Precambrian Palaeolatitudes for Australia: an Update
  8. About "Minerals Alert"

1. Geoscience Australia Minerals Division Annual Seminar

The 2004 Geoscience Australia Minerals Exploration Seminar will be held in Perth on November 29. Themes in the program will be the regional geology and prospectivity of the Yilgarn, Tanami and Gawler; mineral systems, resources and potential particularly for gold and nickel and topics on exploring under cover. Full details of the program and registration details will be available in the next Minerals Alert.

To receive further information as it becomes available please contact Mike Huleatt.

2. Surface geology: Northwest Queensland - western Cape York & Torres Strait (digital)

A new digital data set of northern Queensland has been released as part of a national compilation of the 'Surface Geology of Australia, 1:1,000,000 scale'. It covers the area from the Mount Isa Inlier, Murphy Tectonic Ridge, and eastern McArthur Basin, north to the Torres Strait. The data set was mainly compiled from regional 1:500,000 maps but updated and in filled with 2nd generation 1:250 000 geology. Limited interpretation of Landsat TM and Gamma-ray spectrometric data was also incorporated. The digital data are intended for use at 1:1M scale and have a spatial accuracy of approximately 1 km. Geological unit polygon attributes include stratigraphic names and descriptions, Geoscience Australia stratigraphic index numbers, age, and summary lithology to provide users additional flexibility in search options. Major deposits/resources within the area of the data set include: Mount Isa / George Fisher (Cu-Pb-Zn-Ag); Century (Zn); Ernest Henry (Cu-Au); Cannington (Ag-Pb-Zn); Osborne (Cu-Au); Tick Hill (Au); Duchess Phosphate (P) and Weipa (Al).

This data set can be downloaded from the Geoscience Australia's Free Downloads page, or ordered on CD in ESRI and Mapinfo formats from the Geoscience Australia Sales Centre.

For more details or to provide feedback phone Alan Whitaker

3. New information for gold and nickel exploration in the North Australia Craton

The North Australia Project (NAP) announces the web release of two new products and updates to existing data sets. Geoscience Australia Record 2003-29 uses geophysical datasets to define the extent and 3-D geometry of mafic intrusions in the southern Arunta Province. This analysis has identified a series of concealed mafic bodies along a prominent gravity ridge that includes the Andrew Young Hills Complex. 2-D forward modelling indicates that many of these bodies and the sub-cropping parts of exposed mafic bodies are buried less than 120 m below the surface. Previous work reported in Geoscience Australia Record 2001-39, indicated that these mafic bodies have potential for orthomagmatic Ni-Cu deposits.

A comprehensive proposal for seismic data acquisition in the Tanami Region is also available. This proposal summarises the scientific rationale and logistics of a joint GA-NTGS-GSWA program of seismic acquisition for fiscal year 2004-2005. The seismic data should provide a better understanding of the structural, stratigraphic and magmatic architecture that controls mineralisation in the gold-rich Tanami Region.

For further information contact David Huston.

4. Updated 3D model and GIS for the North Australia Craton

The web-based Tanami 3-D model has been updated to include all major faults as well as magnetic strings, regolith geology and proposed seismic lines, as well as new features to assist in viewing the model. The architecture presented in this model, which was developed by integrating forward modelling of potential field data with existing solid geology interpretations, provides a provisional model which will be tested and refined using inversion and seismic methods. The 3-D model has been developed to assist gold exploration by providing regional architecture of the Tanami Region.

The North Australia Project on-line GIS has been updated to include the majority of geochronological data for the Arunta and Tanami Regions. The update resulted in an increase of 27% in SHRIMP data (to 247 samples). The online GIS also includes fluid inclusion data collected by Geoscience Australia as part of studies of gold mineralisation. This dataset allows for a better understanding of the evolution of the southern North Australia Craton, allowing a more critical assessment of exploration models for Au, Ni-Cu and Zn-Cu-Pb mineralisation.

For further information contact David Huston.

5. Australian Stratigraphic Units Database - updated search features

The Australian Stratigraphic Units Database stores data on defined stratigraphic units in Australia. The database has been expanded to capture and record far more information about geological units within Australia. This information is now even more accessible to users. Recent updates to the website query pages, allow the user to search by a number of criteria including, name, state, age, currency, originator, status or combinations of criteria. View the Stratigraphic Units Database.

6. The Virtual Centre for Geofluids and Thermodynamic Data

The Virtual Centre for Geofluids and Thermodynamic Data has been revamped. It was established by the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC) so that chemical data relevant to geofluids may be stored in and accessed from a single point with the aims of providing an up to date reference centre for thermodynamic data and geofluids from various geological settings. The Cooperative Research Centre for Landscape Environments and Mineral Exploration (CRCLEME) has also contributed to this project so that physical and chemical conditions relevant to the regolith environment can be incorporated.

The new Virtual Centre pages now provide improved web-based access to the new Geoscience Australia FreeGs Thermodynamic Database, which is a database of thermodynamic data of geologically related substances. New styles of reports are available which provide on-the-fly processing of these data to ensure standardisation of input parameters to thermodynamic modelling packages to eliminate inconsistencies.

Full explanation of the FreeGs Database and Reports systems.

For more information contact Evgeniy Bastrakov.

7. Precambrian Palaeolatitudes for Australia: an Update

The Australian Mineral Systems project has produced an updated report on the palaeolatitudes for Precambrian Australia to assist with studies of mineralisation in northern Australia. The last major report on the palaeolatitudes for Precambrian Australia was published in 1988. A serious limitation at that time was the sparseness of palaeomagnetic data. While the Australian Precambrian still lacks palaeomagnetic data on the whole, two intervals within it have since become much better defined. These are the late Palaeoproterozoic to earliest Mesoproterozoic and late the Mesoproterozoic to middle Neoproterozoic. Improvements to the former resulted from multidisciplinary studies in the 1990s by the then AGSO to provide a geological framework for mineral exploration in northern Australia; improvements to the latter are largely due a quest led by the University of Western Australia to determine the configuration of the late Proterozoic supercontinent Rodinia. Download the updated report on the palaeolatitudes for Precambrian Australia.

For more information contact Terry Mernagh.

8. 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.

Topic contact: media@ga.gov.au Last updated: October 4, 2013