Minerals Alert November 2003

  1. Geoscience Australia annual minerals seminar - Perth, 4 December 2003
  2. New products and tools for web delivery of Geoscience Australia data
  3. Australia's Geoscience database goes international
  4. Summaries of some presentations from the annual minerals seminar
  5. National Mines Atlas Stage 2
  6. About Minerals Alert

1. Geoscience Australia Annual Minerals Seminar - Perth, 4 December 2003

Geoscience Australia will host a one-day seminar at The Esplanade Hotel in Fremantle on Thursday 4 December 2003, to present the results of its research to the mineral exploration community.

2. New Products and Tools for Web Delivery of Geoscience Australia data

New products and tools for web delivery of GA data will be unveiled through November and early December and will be demonstrated at the Perth minerals seminar. A brief review of these items follows:

  • Geoscience Australia's airborne geophysics and onshore gravity data are now available for free download from the newly implemented Geoscience Australia Data Delivery System (GADDS). Users can select an area of interest from a map, enter coordinates of interest, or by map sheet, choose from the data available and download the data to their own computer. Data available to date include grids and flight line data. The system has on-screen help.
  • Access to Geoscience Australia's geochronology database is now made easy with a map-based interface that allows users to select regions, lithologies, stratigraphic units and age dating methods and deliver the available geochronology in a table to the computer screen. Users can download the table, or bury deeper into the database by selecting highlighted data points of interest. Concordia plots of SHRIMP ages are also provided so users can make their own judgement of the data quality. This facility will be available in late November. The URL will be announced in What's New on the GA web site.
  • Ever wanted to use Geoscience Australia's geochemistry data? Try our new on-line plotting system PLOT-IT. With PLOT-IT you can extract data directly from our geochemistry database into a table, then sort, select and group data from the table before plotting it in X-Y, ternary, spidergram and histogram plots. Users have access to a simple HTML-enabled version, or to a Java-enabled version that allows them to zoom, pan and manipulate the plotting characteristics, such as colour, symbols etc. Tables of data and plots can be downloaded to the users' PC for later manipulation and display. An on-line help manual is available. PLOT-IT will be available from 18 November.
  • A new 1:1 million scale digital geology dataset of Tasmania is available from Geoscience Australia and Mineral Resources Tasmania. The Tasmanian dataset is the first part of a new 1:1 million scale compilation of the outcrop geology of Australia being carried out at Geoscience Australia. Similar datasets of Victoria and south Queensland are also nearing completion. The new digital data will provide the most detailed and current geological map of the whole nation for explorers, resource managers and land use decision-makers. The new Tasmanian dataset is generalised slightly from the 1:500 000 scale digital "Geology of Tasmania" map released by Mineral Resources Tasmania in 1999. Geological polygons and lines are attributed with stratigraphic, lithological and age information, with standardised descriptions that will be incorporated into the national coverage. The dataset can be downloaded from the Free Downloads page, or ordered on CD in ESRI and Mapinfo formats from the GA Sales Centre.

3. Australia's Geoscience Database goes International

Access to Australian research material about geoscience has been given a new lease of life thanks to a new agreement between Geoscience Australia and the American Geological Institute. "The agreement will provide tangible benefits for the Australian geoscience, mining and petroleum exploration communities. Since the Australian Earth Sciences Information Service (AESIS) folded in 2001, it has become increasingly difficult to find relevant Australian geoscience research material," said Dr Neil Williams, CEO of Geoscience Australia. All major Australian geoscientific publications will now be included on the international GeoRef database so they can be found easily under specifications such as title, author, subject and publication date.The GeoRef database, established by the American Geological Institute in 1966, is the most comprehensive geoscience database in the world and contains 2.4 million references to geoscience journals, books, maps, conference proceedings, reports and theses. Indexed material from Geoscience Australia will appear in GeoRef by November 2003. Geoscience Australia is working in collaboration with State and Territory government geoscience agencies to comprehensively index government geoscience publications and we will also be contacting universities, professional associations and other publishers to include any material they might have. Access to the database, either via the Web or on CD, will be via subscription. Researchers will be able to subscribe to the full GeoRef database, to the Australian content only (AusGeoRef) or to an individually customised alert service. More details about accessing or subscribing to GeoRef are available from the Geoscience Portal www.geoscience.gov.au or www.agiweb.org/georef/index.html

4. Summaries of some presentations from the annual minerals seminar

  • Yilgarn Craton geochronology. Results of U-Pb and Sm-Nd geochronology are used to systematically map the age distribution of granites and felsic volcanic rocks (and their source regions) across the Yilgarn Craton. The results provide new temporal constraints on terrane and domain boundaries, and delineate crustal blocks of varying mineral endowment. For example, in the Eastern Goldfields Province, world-class Au deposits are hosted in regions of relatively 'old' crust. For more information contact Kevin Cassidy on +61 8 6249 9577 or by email at kevin.cassidy@ga.wa.gov.au.
  • Yilgarn Craton deformation framework. A new deformation framework was established by systematically determining the relative event history for granites of different ages in a transect across the late Archaean eastern Yilgarn Craton. The results show many similarities with modern convergent settings viz complexity, rapidity, episodicity, diachroneity, switching tectonic mode (compression-extension), changing stress vectors, and events that are correlatable in time-space. Fluid flow related to orogenic gold may be related to the episodic switches in apparent palaeostress (which may reflect extensional events). For more information contact Richard Blewett on + 61 2 6249 9713 or by email at richard.blewett@ga.gov.au
  • Lode gold mineral systems of the Tanami region: architecture, fluids and timing. This talk presents two aspects of joint GA-NTGS research in the Tanami region. The regional architecture of the Tanami region, which has been inferred using forward modelling of potential field data, will be illustrated using a web-based VRML. A regional study combining fluid inclusions and Ar-Ar dating indicates that CO2-rich fluids with nominal Ar-Ar ages that match that of the Callie deposit are present north of a line that passes from the central Highland Rocks 1:250 000 sheet into the Lander Rock 1:250 000 sheets. South of this line, CO2-rich fluids were not recognized, and the Ar-Ar ages were significantly younger. This latter area, which overlaps with a zone of higher-grade metamorphism, is inferred to represent a deeper crustal level compared with the area to the north. For more information contact David Huston on +61 2 6249 9577 or by email at David.Huston@ga.gov.au
  • Base metal potential of the Tanami-Arunta. This talk presents joint results of GA-NTGS research mainly in the Arunta region. The first aspect covered is a demonstration of the NAP on-line GIS which allows access to geological, geophysical and geochronological data. The GIS allows easy access to the results of SHRIMP and other goechronological investigations. The talk will also present the results of an analysis of base metal occurrences in the eastern Arunta. Our results suggest that although a large number of these deposits are metamorphosed VHMS deposits, other deposit classes, including possible IOCG and carbonate replacement Zn-Cu, are also present. Possible IOCG occurrences may be present elsewhere in the Arunta region. For more information contact David Huston on +61 2 6249 9577 or by email at David.Huston@ga.gov.au
  • A 3D and temporal framework for copper-gold exploration in the Gawler Craton. The Gawler Craton is one of Australia's premier addresses for Proterozoic iron oxide-copper-gold (IOCG) exploration. New results, including geochronology, geochemistry, and 3D inversion modelling of regional magnetic and gravity data, will be presented for the >500 km long Olympic Cu-Au province. These results confirm that Cu-Au-forming hydrothermal systems were active at similar times (~1590-1575 Ma), but at differing crustal levels, in the Mt Woods Inlier, Olympic Dam region and Moonta-Wallaroo district. Preliminary data suggest the gold-only mineralisation in the recently recognised central Gawler gold province also formed over this period. Inversion of geophysical data is showing important relationships in 3D between crustal-scale NW- and NE-trending faults and magnetite- and hematite-rich alteration zones. Several tools will be presented for discriminating potentially mineralised from barren alteration systems, and vectoring towards high-grade mineralisation within them. For more information contact Roger Skirrow on +61 2 6249 9442 or by email at Roger.Skirrow@ga.gov.au.
  • Central Gawler Gold Province. Geoscience Australia, the Minerals Resources Group in the South Australian Department of Primary Industry and Resources and the Co-operative Research Centre for Landscape, Environments and Mineral Exploration have recently established a collaborative research project on the newly identified Central Gawler Gold Province. The province is poorly known and poorly explored principally because of the extensive regolith cover. The project is focused on reducing the risk attached to exploration through cover by developing a methodology for integrating the interpretation of geochemical and geophysical and calcrete geochemical data to establish ranked drilling targets at known prospects.
  • New regional geophysical tools and approaches. Initial regional gravity and magnetic inversions in the Olympic Dam region have returned encouraging results. A 3D geological model of the region is being built and future inversions will use this as a reference. This will help to refine the 3D geological model and ensure that it is consistent with the gravity and magnetic data. Surveys involving airborne gravity and airborne gravity gradiometer systems have been flown. These data are being evaluated so that we can properly consider the role of these new technologies, together with existing ground methods, for upgrading the regional gravity coverage of Australia. For more information contact Richard Lane on +61 2 6249 9264 or by email at richard.lane@ga.gov.au.

5. National Mines Atlas Stage 2

Geoscience Australia is moving to upgrade the National Mines Atlas (NMA) following the award a grant of $20,000 under the Commonwealth Government's Regional Minerals Program to enhance its functionality. The grant will be matched by the same (or a higher) level of funding from the Minerals Council of Australia, a partner in the project. The Council is keen to enhance the functionality of the NMA to meet student and teacher needs. It also views it as a valuable tool in its broader communication strategy. Stage 2 of the NMA, inter alia, will implement the latest MapServer software and an advanced search capability. To view the NMA visit www.nationalminesatlas.gov.au.

For more information contact Bill McKay at +61 2 6249 9003 or email bill.mckay@ga.gov.au

6. 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