Mineral Potential of Australia Project
This project concluded on 30 June 2006.
The Mineral Potential of Australia project completed a GIS-based national 1:2.5 million scale assessment of the potential for undiscovered mineral resources in Australia. Assessments were conducted in consultation with the state and Northern Territory Geological Surveys and were made in response to requests from Australian Government agencies for input on the mineral potential of specific regions. More recent mineral potential assessments can be accessed at the Australian Mines Atlas.
The project also provided advice and reports on potential undiscovered mineral resources to facilitate informed policy decisions on land use, including land access for mineral exploration and mining, in response to requests from Australian Government agencies.
The assessment function of the project is now undertaken by the National Mineral Resources and Advice project.
Background and methodologies
Areas of assessment varied from a few square kilometres to regions in excess of 100 000 square kilometres. Three broad scales of assessments were used::
- detailed assessments of specific regions at a scale of 1:250 000
- regional geoprovince scale of around 1:1 million
- national scale geoprovince scale assessments at 1:2.5 million.
Most mineral potential assessments in the past had been conducted using qualitative methods of mineral potential assessment, but a major project undertaken jointly with State geological surveys involved a GIS-based qualitative assessment. Carried out at a scale of 1:250 000, the assessment involved a total of 12 areas in five States as part of the Regional Forest Agreement (RFA) process. The GIS-based qualitative assessment method that was developed combined:
- elements of a qualitative method used by the United States Geological Survey
- mineral deposit models compiled by Cox and Singer (1986)
- numerical ranking of levels of mineral potential and the weighting of different types of mineral deposits to facilitate computer processing and visualisation of assessment results.
Regional-scale criteria for specific types of mineral deposits was used to delineate mineral potential tracts for each deposit style and assign levels of mineral potential as High, Moderate to High, Moderate, Low to Moderate, Low and Unknown. Levels of certainty for each tract also were assigned according to the amount of information available for each tract.
Assessments for individual deposit styles in the same area were then combined to produce 'composite' and 'cumulative' mineral potential maps for the region. Individual deposit styles also were weighted against each other in terms of economic significance and weighted tracts were combined to produce 'weighted composite' and 'weighted cumulative' mineral potential maps.
The assessment methodology used for the RFA regions is fully described in the reports on mineral resource assessments for southwest Western Australia RFA and for the upper north east RFA region in New South Wales.
Mineral potential assessments at 1:1 million scale were introduced for the assessment of mineral potential of some geological regions studied by Geoscience Australia and the State and Territory Geological Surveys under the National Geoscience Agreement such as the North Australia Project.
An emphasis for the project was the preliminary national geoprovince 1:2.5 million scale assessment of selected significant mineral deposit styles for gold, base metals and uranium. The boundaries of these geoprovinces were largely defined on Geoscience Australia's 1995 1:2.5 million scale geotectonic province map based on WD Palfreyman's Bureau of Mineral Resources Bulletin 181 and on the map of major structural elements (D'Addario, Palfreyman and Bultitude, 1979). Boundaries of subdomains of these geoprovinces were derived from more recent datasets defined by past and current Geoscience Australia regional projects.
Initially, preliminary assessments for selected types of mineral deposits in specific geoprovinces were prepared by Geoscience Australia to trial the methodology being used. The follow-up stage of the assessments involved consultation with the State and Northern Territory Geological Surveys to advance the preliminary assessments, incorporated data from the geological surveys and integrated results of assessments of mineral potential by the States and the Northern Territory.
The methodology used was a modified version of the GIS-based qualitative assessment applied by Geoscience Australia for the assessment of RFA areas. The stages of assessment included:
- compilation of the geology mineral occurrences/deposits for the geoprovince being assessed
- determination of styles of mineral deposits likely to be present in the area including:
- types of mineral deposits known to exist in the geoprovince
- those not known to be present but for which assessment criteria indicate that a favourable environment exists in the geoprovince
- compilation and updating of time-event plots for the geoprovince
- preparation of descriptive mineral deposit models incorporating minerals systems criteria for source of elements/fluid pathways/traps
- definition of geoprovince scale assessment criteria for deposit styles.
Australia's Mineral Resource Assessment