Introduction

• Introduction
• National Resource Classification Scheme
• Accessible Resources
• Resource Life

Geoscience Australia and its predecessors have prepared annual assessments of Australia's mineral resources since 1975. The resource data and related information from Australia's Identified Mineral Resources are used by the Australian Bureau of Statistics and provide input into Australian Government policy decisions associated with the minerals sector, sustainable development of resources and financial allocations. Other Australian Government departments and agencies to utilise the data included the Department of Resources, Energy and Tourism (formerly Department of Industry, Tourism and Resources), the Department of Prime Minister and Cabinet, the Department of Environment, Water, Heritage and the Arts, the Department of Defence, the Office of National Assessments, and the Department of Foreign Affairs and Trade.

Australia's Identified Mineral Resources 2008 presents estimates of Australia's mineral resources for all major and several minor mineral commodities (Table 1) based on published and unpublished data available to Geoscience Australia to the end of December 2007. These resource estimates provide a long term view of what is likely to be mined. They are compared with national totals of ore reserves for each commodity, which provide the industry view of what is likely to be mined in the short to medium term. Mine production data are based on the Australian Bureau of Agricultural and Resource Economics figures. World ranking of Australia's mineral resources have been calculated mainly from information in publications of the United States Geological Survey. A summary of significant industry developments also is presented.

Australia's Identified Mineral Resources 2008 provides information on and analysis of mineral exploration expenditures in Australia for 2006-07 and the calendar year 2007. Trends in expenditure are presented and discussed.

The mineral resource classification scheme used for Australia's national inventory is based on two general criteria: i) the geological certainty of existence of the mineral resource, and ii) the economic feasibility of its extraction over the long term (see Appendix 2 'National classification system for identified mineral resources'). The classification category 'Economic Demonstrated Resources' is used instead of 'reserves' for national totals of economic resources. This is because the term 'reserves' has a specific meaning for individual mineral deposits under the criteria of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, which is known as the JORC Code and is used by industry for reporting ore reserves and mineral resources.

Economic Demonstrated Resources, or EDR, are defined as the total of measured and indicated resources as shown in Appendix 2 for which profitable extraction or production had been established, analytically demonstrated or assumed with reasonable certainty using defined investment assumptions (refer Guideline (iii) in Appendix 2). EDR provided a basis for meaningful comparisons of Australia's economic resources with those of other nations. Ore is generally mined from resources in the EDR category. Longterm trends in EDR for bauxite, black coal, iron ore, gold, copper, nickel, lead, zinc, mineral sands and uranium are presented and the reasons for significant changes in resource trends are noted.

Geoscience Australia also assesses the amount of resources within EDR which are accessible for development and mining. Some mineral deposits are inaccessible for mining currently because of government policies or various environmental and land-access restrictions such as location within National/State parks and conservation zones, military training areas or environmental protection areas or areas over which mining approval has not been granted by traditional owners. Accessible economic demonstrated resources (AEDR) as shown in Table 1 represent the resources within the EDR category that are accessible for mining. It should be noted that the factors which restrict access for mining could be changed or abolished in future.

The national total ore reserves (OR) figures shown in Table 1 are from estimates prepared by companies for mine planning and marketing purposes and generally have a shorter term outlook than EDR. The ratios of EDR/production, AEDR/production and OR/production provide information on the resource life of Australia's mineral commodities based on production rates at the time of assessment. Each of these have deficiencies as an indicator of resource life. OR/production is a more conservative indicator of resource life, and for some commodities very much more conservative, than EDR/ production. The ratios can change quite rapidly through various influences such as major changes in production rates and changes in metal prices.